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| author | Kartik Agaram <vc@akkartik.com> | 2021-03-23 22:27:46 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2021-03-23 22:27:59 -0700 |
| commit | 3120f938c660ab5fcecb579122440d487ccd798e (patch) | |
| tree | da0f72f0ffd3001fa8dc01528d1aeab78bfcda66 /html/boot.subx.html | |
| parent | b663b5797ab5852f4698e5375bff00a413de6396 (diff) | |
| download | mu-3120f938c660ab5fcecb579122440d487ccd798e.tar.gz | |
.
Diffstat (limited to 'html/boot.subx.html')
| -rw-r--r-- | html/boot.subx.html | 1281 |
1 files changed, 552 insertions, 729 deletions
diff --git a/html/boot.subx.html b/html/boot.subx.html index 4518b0d0..5fa48c95 100644 --- a/html/boot.subx.html +++ b/html/boot.subx.html @@ -69,178 +69,178 @@ if ('onhashchange' in window) { <span id="L10" class="LineNr"> 10 </span><span class="subxComment"># uses:</span> <span id="L11" class="LineNr"> 11 </span><span class="subxComment"># - sigils only support 32-bit general-purpose registers, so don't work with segment registers or 16-bit or 8-bit registers</span> <span id="L12" class="LineNr"> 12 </span><span class="subxComment"># - metadata like rm32 and r32 can sometimes misleadingly refer to only the bottom 16 bits of the register; pay attention to the register name</span> -<span id="L13" class="LineNr"> 13 </span> -<span id="L14" class="LineNr"> 14 </span><span class="subxComment"># Memory map of a Mu computer:</span> -<span id="L15" class="LineNr"> 15 </span><span class="subxComment"># code: 4 tracks of disk to [0x00007c00, 0x00027400)</span> -<span id="L16" class="LineNr"> 16 </span><span class="subxComment"># stack grows down from 0x00070000</span> -<span id="L17" class="LineNr"> 17 </span><span class="subxComment"># see below</span> -<span id="L18" class="LineNr"> 18 </span><span class="subxComment"># heap: [0x01000000, 0x02000000)</span> -<span id="L19" class="LineNr"> 19 </span><span class="subxComment"># see 120allocate.subx</span> -<span id="L20" class="LineNr"> 20 </span><span class="subxComment"># Consult <a href="https://wiki.osdev.org/Memory_Map_(x86)">https://wiki.osdev.org/Memory_Map_(x86)</a> before modifying any of this.</span> -<span id="L21" class="LineNr"> 21 </span> -<span id="L22" class="LineNr"> 22 </span>== code +<span id="L13" class="LineNr"> 13 </span><span class="subxComment">#</span> +<span id="L14" class="LineNr"> 14 </span><span class="subxComment"># While most of Mu is thoroughly tested, this file is not. I don't yet</span> +<span id="L15" class="LineNr"> 15 </span><span class="subxComment"># understand hardware interfaces well enough to explain to others.</span> +<span id="L16" class="LineNr"> 16 </span> +<span id="L17" class="LineNr"> 17 </span><span class="subxComment"># Memory map of a Mu computer:</span> +<span id="L18" class="LineNr"> 18 </span><span class="subxComment"># code: currently 4 tracks loaded from the primary disk to [0x00007c00, 0x00027400)</span> +<span id="L19" class="LineNr"> 19 </span><span class="subxComment"># stack: grows down from 0x00070000</span> +<span id="L20" class="LineNr"> 20 </span><span class="subxComment"># heap: [0x01000000, 0x02000000)</span> +<span id="L21" class="LineNr"> 21 </span><span class="subxComment"># see 120allocate.subx</span> +<span id="L22" class="LineNr"> 22 </span><span class="subxComment"># Consult <a href="https://wiki.osdev.org/Memory_Map_(x86)">https://wiki.osdev.org/Memory_Map_(x86)</a> before modifying any of this.</span> <span id="L23" class="LineNr"> 23 </span> -<span id="L24" class="LineNr"> 24 </span><span class="subxComment">## 16-bit entry point: 0x7c00</span> +<span id="L24" class="LineNr"> 24 </span>== code <span id="L25" class="LineNr"> 25 </span> -<span id="L26" class="LineNr"> 26 </span><span class="subxComment"># Upon reset, the IBM PC:</span> -<span id="L27" class="LineNr"> 27 </span><span class="subxComment"># - loads the first sector (512 bytes)</span> -<span id="L28" class="LineNr"> 28 </span><span class="subxComment"># from some bootable image (look for the boot-sector-marker further down this file)</span> -<span id="L29" class="LineNr"> 29 </span><span class="subxComment"># to the address range [0x7c00, 0x7e00)</span> -<span id="L30" class="LineNr"> 30 </span><span class="subxComment"># - starts executing code at address 0x7c00</span> -<span id="L31" class="LineNr"> 31 </span> -<span id="L32" class="LineNr"> 32 </span> fa/disable-interrupts +<span id="L26" class="LineNr"> 26 </span><span class="subxComment">## 16-bit entry point: 0x7c00</span> +<span id="L27" class="LineNr"> 27 </span> +<span id="L28" class="LineNr"> 28 </span><span class="subxComment"># Upon reset, the IBM PC:</span> +<span id="L29" class="LineNr"> 29 </span><span class="subxComment"># - loads the first sector (512 bytes)</span> +<span id="L30" class="LineNr"> 30 </span><span class="subxComment"># from some bootable image (look for the boot-sector-marker further down this file)</span> +<span id="L31" class="LineNr"> 31 </span><span class="subxComment"># to the address range [0x7c00, 0x7e00)</span> +<span id="L32" class="LineNr"> 32 </span><span class="subxComment"># - starts executing code at address 0x7c00</span> <span id="L33" class="LineNr"> 33 </span> -<span id="L34" class="LineNr"> 34 </span> <span class="subxComment"># initialize segment registers</span> -<span id="L35" class="LineNr"> 35 </span> b8/copy-to-ax 0/imm16 -<span id="L36" class="LineNr"> 36 </span> 8e/->seg 3/mod/direct 0/rm32/ax 3/r32/ds -<span id="L37" class="LineNr"> 37 </span> 8e/->seg 3/mod/direct 0/rm32/ax 0/r32/es -<span id="L38" class="LineNr"> 38 </span> 8e/->seg 3/mod/direct 0/rm32/ax 4/r32/fs -<span id="L39" class="LineNr"> 39 </span> 8e/->seg 3/mod/direct 0/rm32/ax 5/r32/gs -<span id="L40" class="LineNr"> 40 </span> -<span id="L41" class="LineNr"> 41 </span> <span class="subxComment"># initialize stack to 0x00070000</span> -<span id="L42" class="LineNr"> 42 </span> <span class="subxComment"># We don't read or write the stack before we get to 32-bit mode, but BIOS</span> -<span id="L43" class="LineNr"> 43 </span> <span class="subxComment"># calls do. We need to move the stack in case BIOS initializes it to some</span> -<span id="L44" class="LineNr"> 44 </span> <span class="subxComment"># low address that we want to write code into.</span> -<span id="L45" class="LineNr"> 45 </span> b8/copy-to-ax 0x7000/imm16 -<span id="L46" class="LineNr"> 46 </span> 8e/->seg 3/mod/direct 0/rm32/ax 2/r32/ss -<span id="L47" class="LineNr"> 47 </span> bc/copy-to-esp 0/imm16 -<span id="L48" class="LineNr"> 48 </span> -<span id="L49" class="LineNr"> 49 </span> <span class="subxComment"># undo the A20 hack: <a href="https://en.wikipedia.org/wiki/A20_line">https://en.wikipedia.org/wiki/A20_line</a></span> -<span id="L50" class="LineNr"> 50 </span> <span class="subxComment"># this is from <a href="https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S">https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S</a></span> -<span id="L51" class="LineNr"> 51 </span> { -<span id="L52" class="LineNr"> 52 </span> e4/read-port-into-al 0x64/imm8 -<span id="L53" class="LineNr"> 53 </span> a8/test-bits-in-al 0x02/imm8 <span class="subxComment"># set zf if bit 1 (second-least significant) is not set</span> -<span id="L54" class="LineNr"> 54 </span> 75/jump-if-!zero <span class="Constant">loop</span>/imm8 -<span id="L55" class="LineNr"> 55 </span> b0/copy-to-al 0xd1/imm8 -<span id="L56" class="LineNr"> 56 </span> e6/write-al-into-port 0x64/imm8 -<span id="L57" class="LineNr"> 57 </span> } -<span id="L58" class="LineNr"> 58 </span> { -<span id="L59" class="LineNr"> 59 </span> e4/read-port-into-al 0x64/imm8 -<span id="L60" class="LineNr"> 60 </span> a8/test-bits-in-al 0x02/imm8 <span class="subxComment"># set zf if bit 1 (second-least significant) is not set</span> -<span id="L61" class="LineNr"> 61 </span> 75/jump-if-!zero <span class="Constant">loop</span>/imm8 -<span id="L62" class="LineNr"> 62 </span> b0/copy-to-al 0xdf/imm8 -<span id="L63" class="LineNr"> 63 </span> e6/write-al-into-port 0x64/imm8 -<span id="L64" class="LineNr"> 64 </span> } -<span id="L65" class="LineNr"> 65 </span> -<span id="L66" class="LineNr"> 66 </span> <span class="subxComment"># load remaining sectors from first two tracks of disk into addresses [0x7e00, 0x17800)</span> -<span id="L67" class="LineNr"> 67 </span> b4/copy-to-ah 2/imm8/read-drive -<span id="L68" class="LineNr"> 68 </span> <span class="subxComment"># dl comes conveniently initialized at boot time with the index of the device being booted</span> -<span id="L69" class="LineNr"> 69 </span> b5/copy-to-ch 0/imm8/cylinder -<span id="L70" class="LineNr"> 70 </span> b6/copy-to-dh 0/imm8/head -<span id="L71" class="LineNr"> 71 </span> b1/copy-to-cl 2/imm8/sector <span class="subxComment"># 1-based</span> -<span id="L72" class="LineNr"> 72 </span> b0/copy-to-al 0x7d/imm8/num-sectors <span class="subxComment"># 2*63 - 1 = 125</span> -<span id="L73" class="LineNr"> 73 </span> <span class="subxComment"># address to write sectors to = es:bx = 0x7e00, contiguous with boot segment</span> -<span id="L74" class="LineNr"> 74 </span> bb/copy-to-bx 0/imm16 -<span id="L75" class="LineNr"> 75 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es -<span id="L76" class="LineNr"> 76 </span> bb/copy-to-bx 0x7e00/imm16 -<span id="L77" class="LineNr"> 77 </span> cd/syscall 0x13/imm8/bios-disk-services -<span id="L78" class="LineNr"> 78 </span> 0f 82/jump-if-carry <a href='boot.subx.html#L144'>disk_error</a>/disp16 -<span id="L79" class="LineNr"> 79 </span> -<span id="L80" class="LineNr"> 80 </span> <span class="subxComment"># load two more tracks of disk into addresses [0x17800, 0x27400)</span> -<span id="L81" class="LineNr"> 81 </span> b4/copy-to-ah 2/imm8/read-drive -<span id="L82" class="LineNr"> 82 </span> <span class="subxComment"># dl comes conveniently initialized at boot time with the index of the device being booted</span> -<span id="L83" class="LineNr"> 83 </span> b5/copy-to-ch 0/imm8/cylinder -<span id="L84" class="LineNr"> 84 </span> b6/copy-to-dh 2/imm8/head -<span id="L85" class="LineNr"> 85 </span> b1/copy-to-cl 1/imm8/sector <span class="subxComment"># 1-based</span> -<span id="L86" class="LineNr"> 86 </span> b0/copy-to-al 0x7e/imm8/num-sectors <span class="subxComment"># 2*63 = 126</span> -<span id="L87" class="LineNr"> 87 </span> <span class="subxComment"># address to write sectors to = es:bx = 0x17800, contiguous with boot segment</span> -<span id="L88" class="LineNr"> 88 </span> bb/copy-to-bx 0x1780/imm16 -<span id="L89" class="LineNr"> 89 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es -<span id="L90" class="LineNr"> 90 </span> bb/copy-to-bx 0/imm16 -<span id="L91" class="LineNr"> 91 </span> cd/syscall 0x13/imm8/bios-disk-services -<span id="L92" class="LineNr"> 92 </span> 0f 82/jump-if-carry <a href='boot.subx.html#L144'>disk_error</a>/disp16 -<span id="L93" class="LineNr"> 93 </span> -<span id="L94" class="LineNr"> 94 </span> <span class="subxComment"># load two more tracks of disk into addresses [0x27400, 0x37000)</span> -<span id="L95" class="LineNr"> 95 </span> b4/copy-to-ah 2/imm8/read-drive -<span id="L96" class="LineNr"> 96 </span> <span class="subxComment"># dl comes conveniently initialized at boot time with the index of the device being booted</span> -<span id="L97" class="LineNr"> 97 </span> b5/copy-to-ch 0/imm8/cylinder -<span id="L98" class="LineNr"> 98 </span> b6/copy-to-dh 4/imm8/head -<span id="L99" class="LineNr"> 99 </span> b1/copy-to-cl 1/imm8/sector <span class="subxComment"># 1-based</span> -<span id="L100" class="LineNr"> 100 </span> b0/copy-to-al 0x7e/imm8/num-sectors <span class="subxComment"># 2*63 = 126</span> -<span id="L101" class="LineNr"> 101 </span> <span class="subxComment"># address to write sectors to = es:bx = 0x27400, contiguous with boot segment</span> -<span id="L102" class="LineNr"> 102 </span> bb/copy-to-bx 0x2740/imm16 -<span id="L103" class="LineNr"> 103 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es -<span id="L104" class="LineNr"> 104 </span> bb/copy-to-bx 0/imm16 -<span id="L105" class="LineNr"> 105 </span> cd/syscall 0x13/imm8/bios-disk-services -<span id="L106" class="LineNr"> 106 </span> 0f 82/jump-if-carry <a href='boot.subx.html#L144'>disk_error</a>/disp16 -<span id="L107" class="LineNr"> 107 </span> -<span id="L108" class="LineNr"> 108 </span> <span class="subxComment"># reset es</span> -<span id="L109" class="LineNr"> 109 </span> bb/copy-to-bx 0/imm16 -<span id="L110" class="LineNr"> 110 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es -<span id="L111" class="LineNr"> 111 </span> -<span id="L112" class="LineNr"> 112 </span> <span class="subxComment"># adjust video mode</span> -<span id="L113" class="LineNr"> 113 </span> b4/copy-to-ah 0x4f/imm8 <span class="subxComment"># VBE commands</span> -<span id="L114" class="LineNr"> 114 </span> b0/copy-to-al 2/imm8 <span class="subxComment"># set video mode</span> -<span id="L115" class="LineNr"> 115 </span> bb/copy-to-bx 0x4105/imm16 <span class="subxComment"># 0x0105 | 0x4000</span> -<span id="L116" class="LineNr"> 116 </span> <span class="subxComment"># 0x0105 = graphics mode 1024x768x256</span> -<span id="L117" class="LineNr"> 117 </span> <span class="subxComment"># (alternative candidate: 0x0101 for 640x480x256)</span> -<span id="L118" class="LineNr"> 118 </span> <span class="subxComment"># 0x4000 bit = configure linear frame buffer in Bochs emulator; hopefully this doesn't hurt anything when running natively</span> -<span id="L119" class="LineNr"> 119 </span> cd/syscall 0x10/imm8/bios-video-services -<span id="L120" class="LineNr"> 120 </span> -<span id="L121" class="LineNr"> 121 </span> <span class="subxComment"># load information for the (hopefully) current video mode</span> -<span id="L122" class="LineNr"> 122 </span> <span class="subxComment"># mostly just for the address to the linear frame buffer</span> -<span id="L123" class="LineNr"> 123 </span> b4/copy-to-ah 0x4f/imm8 <span class="subxComment"># VBE commands</span> -<span id="L124" class="LineNr"> 124 </span> b0/copy-to-al 1/imm8 <span class="subxComment"># get video mode info</span> -<span id="L125" class="LineNr"> 125 </span> b9/copy-to-cx 0x0105/imm16 <span class="subxComment"># mode we requested</span> -<span id="L126" class="LineNr"> 126 </span> bf/copy-to-di <span class="SpecialChar"><a href='boot.subx.html#L385'>Video-mode-info</a></span>/imm16 -<span id="L127" class="LineNr"> 127 </span> cd/syscall 0x10/imm8/bios-video-services -<span id="L128" class="LineNr"> 128 </span> -<span id="L129" class="LineNr"> 129 </span> <span class="subxComment">## switch to 32-bit mode</span> -<span id="L130" class="LineNr"> 130 </span> <span class="subxComment"># load global descriptor table</span> -<span id="L131" class="LineNr"> 131 </span> <span class="subxComment"># We can't refer to the label directly because SubX doesn't do the right</span> -<span id="L132" class="LineNr"> 132 </span> <span class="subxComment"># thing for lgdt, so rather than make errors worse in most places we instead</span> -<span id="L133" class="LineNr"> 133 </span> <span class="subxComment"># pin gdt_descriptor below.</span> -<span id="L134" class="LineNr"> 134 </span> 0f 01 2/subop/lgdt 0/mod/indirect 6/rm32/use-disp16 0x7cf8/disp16/gdt_descriptor -<span id="L135" class="LineNr"> 135 </span> <span class="subxComment"># enable paging</span> -<span id="L136" class="LineNr"> 136 </span> 0f 20/<-cr 3/mod/direct 0/rm32/eax 0/r32/cr0 -<span id="L137" class="LineNr"> 137 </span> 66 83 1/subop/or 3/mod/direct 0/rm32/eax 1/imm8 <span class="subxComment"># eax <- or 0x1</span> -<span id="L138" class="LineNr"> 138 </span> 0f 22/->cr 3/mod/direct 0/rm32/eax 0/r32/cr0 -<span id="L139" class="LineNr"> 139 </span> <span class="subxComment"># far jump to initialize_32bit_mode that sets cs to offset 8 in the gdt in the process</span> -<span id="L140" class="LineNr"> 140 </span> <span class="subxComment"># We can't refer to the label directly because SubX doesn't have syntax for</span> -<span id="L141" class="LineNr"> 141 </span> <span class="subxComment"># segment selectors. So we instead pin initialize_32bit_mode below.</span> -<span id="L142" class="LineNr"> 142 </span> ea/jump-far-absolute 0x00087d00/disp32 <span class="subxComment"># address 0x7d00 in offset 8 of the gdt</span> -<span id="L143" class="LineNr"> 143 </span> -<span id="L144" class="LineNr"> 144 </span><span class="subxFunction">disk_error</span>: -<span id="L145" class="LineNr"> 145 </span> <span class="subxComment"># print 'D' to top-left of screen to indicate disk error</span> -<span id="L146" class="LineNr"> 146 </span> <span class="subxComment"># *0xb8000 <- 0x0f44</span> -<span id="L147" class="LineNr"> 147 </span> bb/copy-to-bx 0xb800/imm16 -<span id="L148" class="LineNr"> 148 </span> 8e/->seg 3/mod/direct 3/rm32/bx 3/r32/ds -<span id="L149" class="LineNr"> 149 </span> b0/copy-to-al 0x44/imm8/D -<span id="L150" class="LineNr"> 150 </span> b4/copy-to-ah 0x0f/imm8/white-on-black -<span id="L151" class="LineNr"> 151 </span> bb/copy-to-bx 0/imm16 -<span id="L152" class="LineNr"> 152 </span> 89/<- 0/mod/indirect 7/rm32/bx 0/r32/ax <span class="subxComment"># *ds:bx <- ax</span> -<span id="L153" class="LineNr"> 153 </span> <span class="subxComment"># loop forever</span> -<span id="L154" class="LineNr"> 154 </span> { -<span id="L155" class="LineNr"> 155 </span> eb/jump <span class="Constant">loop</span>/disp8 -<span id="L156" class="LineNr"> 156 </span> } -<span id="L157" class="LineNr"> 157 </span> -<span id="L158" class="LineNr"> 158 </span><span class="subxComment">## GDT: 3 records of 8 bytes each</span> -<span id="L159" class="LineNr"> 159 </span>== data -<span id="L160" class="LineNr"> 160 </span> -<span id="L161" class="LineNr"> 161 </span><span class="subxFunction">gdt_start</span>: -<span id="L162" class="LineNr"> 162 </span><span class="subxComment"># offset 0: gdt_null: mandatory null descriptor</span> -<span id="L163" class="LineNr"> 163 </span> 00 00 00 00 00 00 00 00 -<span id="L164" class="LineNr"> 164 </span><span class="subxComment"># offset 8: gdt_code</span> -<span id="L165" class="LineNr"> 165 </span> ff ff <span class="subxComment"># limit[0:16]</span> -<span id="L166" class="LineNr"> 166 </span> 00 00 00 <span class="subxComment"># base[0:24]</span> -<span id="L167" class="LineNr"> 167 </span> 9a <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span> -<span id="L168" class="LineNr"> 168 </span> <span class="subxComment"># 1/code 0/conforming 1/readable 0/accessed = 1010b</span> -<span id="L169" class="LineNr"> 169 </span> cf <span class="subxComment"># 1/granularity 1/32-bit 0/64-bit-segment 0/AVL = 1100b</span> -<span id="L170" class="LineNr"> 170 </span> <span class="subxComment"># limit[16:20] = 1111b</span> -<span id="L171" class="LineNr"> 171 </span> 00 <span class="subxComment"># base[24:32]</span> -<span id="L172" class="LineNr"> 172 </span><span class="subxComment"># offset 16: gdt_data</span> -<span id="L173" class="LineNr"> 173 </span> ff ff <span class="subxComment"># limit[0:16]</span> -<span id="L174" class="LineNr"> 174 </span> 00 00 00 <span class="subxComment"># base[0:24]</span> -<span id="L175" class="LineNr"> 175 </span> 92 <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span> -<span id="L176" class="LineNr"> 176 </span> <span class="subxComment"># 0/data 0/conforming 1/readable 0/accessed = 0010b</span> -<span id="L177" class="LineNr"> 177 </span> cf <span class="subxComment"># same as gdt_code</span> -<span id="L178" class="LineNr"> 178 </span> 00 <span class="subxComment"># base[24:32]</span> -<span id="L179" class="LineNr"> 179 </span><span class="subxComment"># gdt_end:</span> -<span id="L180" class="LineNr"> 180 </span> -<span id="L181" class="LineNr"> 181 </span>== data 0x7cf8 -<span id="L182" class="LineNr"> 182 </span><span class="subxFunction">gdt_descriptor</span>: -<span id="L183" class="LineNr"> 183 </span> 0x17/imm16 <span class="subxComment"># final index of gdt = size of gdt - 1</span> -<span id="L184" class="LineNr"> 184 </span> <a href='boot.subx.html#L161'>gdt_start</a>/imm32/start +<span id="L34" class="LineNr"> 34 </span> fa/disable-interrupts +<span id="L35" class="LineNr"> 35 </span> +<span id="L36" class="LineNr"> 36 </span> <span class="subxComment"># initialize segment registers</span> +<span id="L37" class="LineNr"> 37 </span> b8/copy-to-ax 0/imm16 +<span id="L38" class="LineNr"> 38 </span> 8e/->seg 3/mod/direct 0/rm32/ax 3/r32/ds +<span id="L39" class="LineNr"> 39 </span> 8e/->seg 3/mod/direct 0/rm32/ax 0/r32/es +<span id="L40" class="LineNr"> 40 </span> 8e/->seg 3/mod/direct 0/rm32/ax 4/r32/fs +<span id="L41" class="LineNr"> 41 </span> 8e/->seg 3/mod/direct 0/rm32/ax 5/r32/gs +<span id="L42" class="LineNr"> 42 </span> +<span id="L43" class="LineNr"> 43 </span> <span class="subxComment"># initialize stack to 0x00070000</span> +<span id="L44" class="LineNr"> 44 </span> <span class="subxComment"># We don't read or write the stack before we get to 32-bit mode, but BIOS</span> +<span id="L45" class="LineNr"> 45 </span> <span class="subxComment"># calls do. We need to move the stack in case BIOS initializes it to some</span> +<span id="L46" class="LineNr"> 46 </span> <span class="subxComment"># low address that we want to write code into.</span> +<span id="L47" class="LineNr"> 47 </span> b8/copy-to-ax 0x7000/imm16 +<span id="L48" class="LineNr"> 48 </span> 8e/->seg 3/mod/direct 0/rm32/ax 2/r32/ss +<span id="L49" class="LineNr"> 49 </span> bc/copy-to-esp 0/imm16 +<span id="L50" class="LineNr"> 50 </span> +<span id="L51" class="LineNr"> 51 </span> <span class="subxComment"># undo the A20 hack: <a href="https://en.wikipedia.org/wiki/A20_line">https://en.wikipedia.org/wiki/A20_line</a></span> +<span id="L52" class="LineNr"> 52 </span> <span class="subxComment"># this is from <a href="https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S">https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S</a></span> +<span id="L53" class="LineNr"> 53 </span> { +<span id="L54" class="LineNr"> 54 </span> e4/read-port-into-al 0x64/imm8 +<span id="L55" class="LineNr"> 55 </span> a8/test-bits-in-al 0x02/imm8 <span class="subxComment"># set zf if bit 1 (second-least significant) is not set</span> +<span id="L56" class="LineNr"> 56 </span> 75/jump-if-!zero <span class="Constant">loop</span>/imm8 +<span id="L57" class="LineNr"> 57 </span> b0/copy-to-al 0xd1/imm8 +<span id="L58" class="LineNr"> 58 </span> e6/write-al-into-port 0x64/imm8 +<span id="L59" class="LineNr"> 59 </span> } +<span id="L60" class="LineNr"> 60 </span> { +<span id="L61" class="LineNr"> 61 </span> e4/read-port-into-al 0x64/imm8 +<span id="L62" class="LineNr"> 62 </span> a8/test-bits-in-al 0x02/imm8 <span class="subxComment"># set zf if bit 1 (second-least significant) is not set</span> +<span id="L63" class="LineNr"> 63 </span> 75/jump-if-!zero <span class="Constant">loop</span>/imm8 +<span id="L64" class="LineNr"> 64 </span> b0/copy-to-al 0xdf/imm8 +<span id="L65" class="LineNr"> 65 </span> e6/write-al-into-port 0x64/imm8 +<span id="L66" class="LineNr"> 66 </span> } +<span id="L67" class="LineNr"> 67 </span> +<span id="L68" class="LineNr"> 68 </span> <span class="subxComment"># load remaining sectors from first two tracks of disk into addresses [0x7e00, 0x17800)</span> +<span id="L69" class="LineNr"> 69 </span> b4/copy-to-ah 2/imm8/read-drive +<span id="L70" class="LineNr"> 70 </span> <span class="subxComment"># dl comes conveniently initialized at boot time with the index of the device being booted</span> +<span id="L71" class="LineNr"> 71 </span> b5/copy-to-ch 0/imm8/cylinder +<span id="L72" class="LineNr"> 72 </span> b6/copy-to-dh 0/imm8/head +<span id="L73" class="LineNr"> 73 </span> b1/copy-to-cl 2/imm8/sector <span class="subxComment"># 1-based</span> +<span id="L74" class="LineNr"> 74 </span> b0/copy-to-al 0x7d/imm8/num-sectors <span class="subxComment"># 2*63 - 1 = 125</span> +<span id="L75" class="LineNr"> 75 </span> <span class="subxComment"># address to write sectors to = es:bx = 0x7e00, contiguous with boot segment</span> +<span id="L76" class="LineNr"> 76 </span> bb/copy-to-bx 0/imm16 +<span id="L77" class="LineNr"> 77 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es +<span id="L78" class="LineNr"> 78 </span> bb/copy-to-bx 0x7e00/imm16 +<span id="L79" class="LineNr"> 79 </span> cd/syscall 0x13/imm8/bios-disk-services +<span id="L80" class="LineNr"> 80 </span> 0f 82/jump-if-carry <a href='boot.subx.html#L146'>disk_error</a>/disp16 +<span id="L81" class="LineNr"> 81 </span> +<span id="L82" class="LineNr"> 82 </span> <span class="subxComment"># load two more tracks of disk into addresses [0x17800, 0x27400)</span> +<span id="L83" class="LineNr"> 83 </span> b4/copy-to-ah 2/imm8/read-drive +<span id="L84" class="LineNr"> 84 </span> <span class="subxComment"># dl comes conveniently initialized at boot time with the index of the device being booted</span> +<span id="L85" class="LineNr"> 85 </span> b5/copy-to-ch 0/imm8/cylinder +<span id="L86" class="LineNr"> 86 </span> b6/copy-to-dh 2/imm8/head +<span id="L87" class="LineNr"> 87 </span> b1/copy-to-cl 1/imm8/sector <span class="subxComment"># 1-based</span> +<span id="L88" class="LineNr"> 88 </span> b0/copy-to-al 0x7e/imm8/num-sectors <span class="subxComment"># 2*63 = 126</span> +<span id="L89" class="LineNr"> 89 </span> <span class="subxComment"># address to write sectors to = es:bx = 0x17800, contiguous with boot segment</span> +<span id="L90" class="LineNr"> 90 </span> bb/copy-to-bx 0x1780/imm16 +<span id="L91" class="LineNr"> 91 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es +<span id="L92" class="LineNr"> 92 </span> bb/copy-to-bx 0/imm16 +<span id="L93" class="LineNr"> 93 </span> cd/syscall 0x13/imm8/bios-disk-services +<span id="L94" class="LineNr"> 94 </span> 0f 82/jump-if-carry <a href='boot.subx.html#L146'>disk_error</a>/disp16 +<span id="L95" class="LineNr"> 95 </span> +<span id="L96" class="LineNr"> 96 </span> <span class="subxComment"># load two more tracks of disk into addresses [0x27400, 0x37000)</span> +<span id="L97" class="LineNr"> 97 </span> b4/copy-to-ah 2/imm8/read-drive +<span id="L98" class="LineNr"> 98 </span> <span class="subxComment"># dl comes conveniently initialized at boot time with the index of the device being booted</span> +<span id="L99" class="LineNr"> 99 </span> b5/copy-to-ch 0/imm8/cylinder +<span id="L100" class="LineNr"> 100 </span> b6/copy-to-dh 4/imm8/head +<span id="L101" class="LineNr"> 101 </span> b1/copy-to-cl 1/imm8/sector <span class="subxComment"># 1-based</span> +<span id="L102" class="LineNr"> 102 </span> b0/copy-to-al 0x7e/imm8/num-sectors <span class="subxComment"># 2*63 = 126</span> +<span id="L103" class="LineNr"> 103 </span> <span class="subxComment"># address to write sectors to = es:bx = 0x27400, contiguous with boot segment</span> +<span id="L104" class="LineNr"> 104 </span> bb/copy-to-bx 0x2740/imm16 +<span id="L105" class="LineNr"> 105 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es +<span id="L106" class="LineNr"> 106 </span> bb/copy-to-bx 0/imm16 +<span id="L107" class="LineNr"> 107 </span> cd/syscall 0x13/imm8/bios-disk-services +<span id="L108" class="LineNr"> 108 </span> 0f 82/jump-if-carry <a href='boot.subx.html#L146'>disk_error</a>/disp16 +<span id="L109" class="LineNr"> 109 </span> +<span id="L110" class="LineNr"> 110 </span> <span class="subxComment"># reset es</span> +<span id="L111" class="LineNr"> 111 </span> bb/copy-to-bx 0/imm16 +<span id="L112" class="LineNr"> 112 </span> 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es +<span id="L113" class="LineNr"> 113 </span> +<span id="L114" class="LineNr"> 114 </span> <span class="subxComment"># adjust video mode</span> +<span id="L115" class="LineNr"> 115 </span> b4/copy-to-ah 0x4f/imm8 <span class="subxComment"># VBE commands</span> +<span id="L116" class="LineNr"> 116 </span> b0/copy-to-al 2/imm8 <span class="subxComment"># set video mode</span> +<span id="L117" class="LineNr"> 117 </span> bb/copy-to-bx 0x4105/imm16 <span class="subxComment"># 0x0105 | 0x4000</span> +<span id="L118" class="LineNr"> 118 </span> <span class="subxComment"># 0x0105 = graphics mode 1024x768x256</span> +<span id="L119" class="LineNr"> 119 </span> <span class="subxComment"># (alternative candidate: 0x0101 for 640x480x256)</span> +<span id="L120" class="LineNr"> 120 </span> <span class="subxComment"># 0x4000 bit = configure linear frame buffer in Bochs emulator; hopefully this doesn't hurt anything when running natively</span> +<span id="L121" class="LineNr"> 121 </span> cd/syscall 0x10/imm8/bios-video-services +<span id="L122" class="LineNr"> 122 </span> +<span id="L123" class="LineNr"> 123 </span> <span class="subxComment"># load information for the (hopefully) current video mode</span> +<span id="L124" class="LineNr"> 124 </span> <span class="subxComment"># mostly just for the address to the linear frame buffer</span> +<span id="L125" class="LineNr"> 125 </span> b4/copy-to-ah 0x4f/imm8 <span class="subxComment"># VBE commands</span> +<span id="L126" class="LineNr"> 126 </span> b0/copy-to-al 1/imm8 <span class="subxComment"># get video mode info</span> +<span id="L127" class="LineNr"> 127 </span> b9/copy-to-cx 0x0105/imm16 <span class="subxComment"># mode we requested</span> +<span id="L128" class="LineNr"> 128 </span> bf/copy-to-di <span class="SpecialChar"><a href='boot.subx.html#L513'>Video-mode-info</a></span>/imm16 +<span id="L129" class="LineNr"> 129 </span> cd/syscall 0x10/imm8/bios-video-services +<span id="L130" class="LineNr"> 130 </span> +<span id="L131" class="LineNr"> 131 </span> <span class="subxComment">## switch to 32-bit mode</span> +<span id="L132" class="LineNr"> 132 </span> <span class="subxComment"># load global descriptor table</span> +<span id="L133" class="LineNr"> 133 </span> <span class="subxComment"># We can't refer to the label directly because SubX doesn't do the right</span> +<span id="L134" class="LineNr"> 134 </span> <span class="subxComment"># thing for lgdt, so rather than make errors worse in most places we instead</span> +<span id="L135" class="LineNr"> 135 </span> <span class="subxComment"># pin gdt_descriptor below.</span> +<span id="L136" class="LineNr"> 136 </span> 0f 01 2/subop/lgdt 0/mod/indirect 6/rm32/use-disp16 0x7ce0/disp16/gdt_descriptor +<span id="L137" class="LineNr"> 137 </span> <span class="subxComment"># enable paging</span> +<span id="L138" class="LineNr"> 138 </span> 0f 20/<-cr 3/mod/direct 0/rm32/eax 0/r32/cr0 +<span id="L139" class="LineNr"> 139 </span> 66 83 1/subop/or 3/mod/direct 0/rm32/eax 1/imm8 <span class="subxComment"># eax <- or 0x1</span> +<span id="L140" class="LineNr"> 140 </span> 0f 22/->cr 3/mod/direct 0/rm32/eax 0/r32/cr0 +<span id="L141" class="LineNr"> 141 </span> <span class="subxComment"># far jump to initialize_32bit_mode that sets cs to offset 8 in the gdt in the process</span> +<span id="L142" class="LineNr"> 142 </span> <span class="subxComment"># We can't refer to the label directly because SubX doesn't have syntax for</span> +<span id="L143" class="LineNr"> 143 </span> <span class="subxComment"># segment selectors. So we instead pin initialize_32bit_mode below.</span> +<span id="L144" class="LineNr"> 144 </span> ea/jump-far-absolute 0x00087d00/disp32 <span class="subxComment"># address 0x7d00 in offset 8 of the gdt</span> +<span id="L145" class="LineNr"> 145 </span> +<span id="L146" class="LineNr"> 146 </span><span class="subxFunction">disk_error</span>: +<span id="L147" class="LineNr"> 147 </span> <span class="subxComment"># print 'D' to top-left of screen to indicate disk error</span> +<span id="L148" class="LineNr"> 148 </span> <span class="subxComment"># *0xb8000 <- 0x0f44</span> +<span id="L149" class="LineNr"> 149 </span> bb/copy-to-bx 0xb800/imm16 +<span id="L150" class="LineNr"> 150 </span> 8e/->seg 3/mod/direct 3/rm32/bx 3/r32/ds +<span id="L151" class="LineNr"> 151 </span> b0/copy-to-al 0x44/imm8/D +<span id="L152" class="LineNr"> 152 </span> b4/copy-to-ah 0x0f/imm8/white-on-black +<span id="L153" class="LineNr"> 153 </span> bb/copy-to-bx 0/imm16 +<span id="L154" class="LineNr"> 154 </span> 89/<- 0/mod/indirect 7/rm32/bx 0/r32/ax <span class="subxComment"># *ds:bx <- ax</span> +<span id="L155" class="LineNr"> 155 </span> <span class="subxComment"># loop forever</span> +<span id="L156" class="LineNr"> 156 </span> { +<span id="L157" class="LineNr"> 157 </span> eb/jump <span class="Constant">loop</span>/disp8 +<span id="L158" class="LineNr"> 158 </span> } +<span id="L159" class="LineNr"> 159 </span> +<span id="L160" class="LineNr"> 160 </span><span class="subxComment">## GDT: 3 records of 8 bytes each</span> +<span id="L161" class="LineNr"> 161 </span>== data 0x7ce0 +<span id="L162" class="LineNr"> 162 </span><span class="subxFunction">gdt_descriptor</span>: +<span id="L163" class="LineNr"> 163 </span> 0x17/imm16 <span class="subxComment"># final index of gdt = size of gdt - 1</span> +<span id="L164" class="LineNr"> 164 </span> <a href='boot.subx.html#L166'>gdt_start</a>/imm32/start +<span id="L165" class="LineNr"> 165 </span> +<span id="L166" class="LineNr"> 166 </span><span class="subxFunction">gdt_start</span>: +<span id="L167" class="LineNr"> 167 </span><span class="subxComment"># offset 0: gdt_null: mandatory null descriptor</span> +<span id="L168" class="LineNr"> 168 </span> 00 00 00 00 00 00 00 00 +<span id="L169" class="LineNr"> 169 </span><span class="subxComment"># offset 8: gdt_code</span> +<span id="L170" class="LineNr"> 170 </span> ff ff <span class="subxComment"># limit[0:16]</span> +<span id="L171" class="LineNr"> 171 </span> 00 00 00 <span class="subxComment"># base[0:24]</span> +<span id="L172" class="LineNr"> 172 </span> 9a <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span> +<span id="L173" class="LineNr"> 173 </span> <span class="subxComment"># 1/code 0/conforming 1/readable 0/accessed = 1010b</span> +<span id="L174" class="LineNr"> 174 </span> cf <span class="subxComment"># 1/granularity 1/32-bit 0/64-bit-segment 0/AVL = 1100b</span> +<span id="L175" class="LineNr"> 175 </span> <span class="subxComment"># limit[16:20] = 1111b</span> +<span id="L176" class="LineNr"> 176 </span> 00 <span class="subxComment"># base[24:32]</span> +<span id="L177" class="LineNr"> 177 </span><span class="subxComment"># offset 16: gdt_data</span> +<span id="L178" class="LineNr"> 178 </span> ff ff <span class="subxComment"># limit[0:16]</span> +<span id="L179" class="LineNr"> 179 </span> 00 00 00 <span class="subxComment"># base[0:24]</span> +<span id="L180" class="LineNr"> 180 </span> 92 <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span> +<span id="L181" class="LineNr"> 181 </span> <span class="subxComment"># 0/data 0/conforming 1/readable 0/accessed = 0010b</span> +<span id="L182" class="LineNr"> 182 </span> cf <span class="subxComment"># same as gdt_code</span> +<span id="L183" class="LineNr"> 183 </span> 00 <span class="subxComment"># base[24:32]</span> +<span id="L184" class="LineNr"> 184 </span><span class="subxComment"># gdt_end:</span> <span id="L185" class="LineNr"> 185 </span> <span id="L186" class="LineNr"> 186 </span><span class="subxComment">## 32-bit code from this point</span> <span id="L187" class="LineNr"> 187 </span> @@ -259,7 +259,7 @@ if ('onhashchange' in window) { <span id="L200" class="LineNr"> 200 </span> <span class="subxComment"># We can't refer to the label directly because SubX doesn't do the right</span> <span id="L201" class="LineNr"> 201 </span> <span class="subxComment"># thing for lidt, so rather than make errors worse in most places we instead</span> <span id="L202" class="LineNr"> 202 </span> <span class="subxComment"># pin idt_descriptor below.</span> -<span id="L203" class="LineNr"> 203 </span> 0f 01 3/subop/lidt 0/mod/indirect 5/rm32/use-disp32 0x8000/disp32/idt_descriptor +<span id="L203" class="LineNr"> 203 </span> 0f 01 3/subop/lidt 0/mod/indirect 5/rm32/use-disp32 0x7e00/disp32/idt_descriptor <span id="L204" class="LineNr"> 204 </span> <span id="L205" class="LineNr"> 205 </span> <span class="subxComment"># For now, not bothering reprogramming the IRQ to not conflict with software</span> <span id="L206" class="LineNr"> 206 </span> <span class="subxComment"># exceptions.</span> @@ -276,566 +276,389 @@ if ('onhashchange' in window) { <span id="L217" class="LineNr"> 217 </span> <span id="L218" class="LineNr"> 218 </span> fb/enable-interrupts <span id="L219" class="LineNr"> 219 </span> -<span id="L220" class="LineNr"> 220 </span> <span class="subxComment">## enable floating point</span> -<span id="L221" class="LineNr"> 221 </span> db/floating-point-coprocessor e3/initialize -<span id="L222" class="LineNr"> 222 </span> <span class="subxComment"># eax <- cr4</span> -<span id="L223" class="LineNr"> 223 </span> 0f 20/<-cr 3/mod/direct 0/rm32/eax 4/r32/cr4 -<span id="L224" class="LineNr"> 224 </span> <span class="subxComment"># eax <- or bit 9</span> -<span id="L225" class="LineNr"> 225 </span> 0f ba/bit-test 5/subop/bit-test-and-set 3/mod/direct 0/rm32/eax 9/imm8 -<span id="L226" class="LineNr"> 226 </span> <span class="subxComment"># cr4 <- eax</span> -<span id="L227" class="LineNr"> 227 </span> 0f 22/->cr 3/mod/direct 0/rm32/eax 4/r32/cr4 -<span id="L228" class="LineNr"> 228 </span> -<span id="L229" class="LineNr"> 229 </span> e9/jump <span class="SpecialChar">Entry</span>/disp32 +<span id="L220" class="LineNr"> 220 </span> (<a href='boot.subx.html#L1277'>initialize-mouse</a>) +<span id="L221" class="LineNr"> 221 </span> +<span id="L222" class="LineNr"> 222 </span> <span class="subxComment">## enable floating point</span> +<span id="L223" class="LineNr"> 223 </span> db/floating-point-coprocessor e3/initialize +<span id="L224" class="LineNr"> 224 </span> <span class="subxComment"># eax <- cr4</span> +<span id="L225" class="LineNr"> 225 </span> 0f 20/<-cr 3/mod/direct 0/rm32/eax 4/r32/cr4 +<span id="L226" class="LineNr"> 226 </span> <span class="subxComment"># eax <- or bit 9</span> +<span id="L227" class="LineNr"> 227 </span> 0f ba/bit-test 5/subop/bit-test-and-set 3/mod/direct 0/rm32/eax 9/imm8 +<span id="L228" class="LineNr"> 228 </span> <span class="subxComment"># cr4 <- eax</span> +<span id="L229" class="LineNr"> 229 </span> 0f 22/->cr 3/mod/direct 0/rm32/eax 4/r32/cr4 <span id="L230" class="LineNr"> 230 </span> -<span id="L231" class="LineNr"> 231 </span>== boot-sector-marker 0x7dfe -<span id="L232" class="LineNr"> 232 </span><span class="subxComment"># final 2 bytes of boot sector</span> -<span id="L233" class="LineNr"> 233 </span>55 aa -<span id="L234" class="LineNr"> 234 </span> -<span id="L235" class="LineNr"> 235 </span><span class="subxComment">## sector 2 onwards loaded by load_disk, not automatically on boot</span> -<span id="L236" class="LineNr"> 236 </span>== code -<span id="L237" class="LineNr"> 237 </span> -<span id="L238" class="LineNr"> 238 </span><span class="subxFunction">null-interrupt-handler</span>: -<span id="L239" class="LineNr"> 239 </span> cf/return-from-interrupt -<span id="L240" class="LineNr"> 240 </span> -<span id="L241" class="LineNr"> 241 </span><span class="subxFunction">keyboard-interrupt-handler</span>: -<span id="L242" class="LineNr"> 242 </span> <span class="subxComment"># prologue</span> -<span id="L243" class="LineNr"> 243 </span> fa/disable-interrupts -<span id="L244" class="LineNr"> 244 </span> 60/push-all-registers -<span id="L245" class="LineNr"> 245 </span> <span class="subxComment"># acknowledge interrupt</span> -<span id="L246" class="LineNr"> 246 </span> b0/copy-to-al 0x20/imm8 -<span id="L247" class="LineNr"> 247 </span> e6/write-al-into-port 0x20/imm8 -<span id="L248" class="LineNr"> 248 </span> 31/xor %eax 0/r32/eax -<span id="L249" class="LineNr"> 249 </span> <span class="subxComment"># check output buffer of 8042 keyboard controller (<a href="https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)">https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)</a></span> -<span id="L250" class="LineNr"> 250 </span> e4/read-port-into-al 0x64/imm8 -<span id="L251" class="LineNr"> 251 </span> a8/test-bits-in-al 0x01/imm8 <span class="subxComment"># set zf if bit 0 (least significant) is not set</span> -<span id="L252" class="LineNr"> 252 </span> 74/jump-if-not-set $keyboard-interrupt-handler:epilogue/disp8 -<span id="L253" class="LineNr"> 253 </span> <span class="subxH1Comment"># - if keyboard buffer is full, return</span> -<span id="L254" class="LineNr"> 254 </span> <span class="subxComment"># var dest-addr/ecx: (addr byte) = (keyboard-buffer + *keyboard-buffer:write)</span> -<span id="L255" class="LineNr"> 255 </span> 31/xor %ecx 1/r32/ecx -<span id="L256" class="LineNr"> 256 </span> 8a/byte-> *<span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a> 1/r32/cl -<span id="L257" class="LineNr"> 257 </span> 81 0/subop/add %ecx <span class="SpecialChar">Keyboard-buffer</span>:data/imm32 -<span id="L258" class="LineNr"> 258 </span> <span class="subxComment"># al = *dest-addr</span> -<span id="L259" class="LineNr"> 259 </span> 8a/byte-> *ecx 0/r32/al -<span id="L260" class="LineNr"> 260 </span> <span class="subxComment"># if (al != 0) return</span> -<span id="L261" class="LineNr"> 261 </span> 3c/compare-al-and 0/imm8 -<span id="L262" class="LineNr"> 262 </span> 75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8 -<span id="L263" class="LineNr"> 263 </span> <span class="subxH1Comment"># - read keycode</span> -<span id="L264" class="LineNr"> 264 </span> e4/read-port-into-al 0x60/imm8 -<span id="L265" class="LineNr"> 265 </span> <span class="subxH1Comment"># - key released</span> -<span id="L266" class="LineNr"> 266 </span> <span class="subxComment"># if (al == 0xaa) shift = false # left shift is being lifted</span> -<span id="L267" class="LineNr"> 267 </span> { -<span id="L268" class="LineNr"> 268 </span> 3c/compare-al-and 0xaa/imm8 -<span id="L269" class="LineNr"> 269 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L270" class="LineNr"> 270 </span> <span class="subxComment"># *shift = 0</span> -<span id="L271" class="LineNr"> 271 </span> c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32 -<span id="L272" class="LineNr"> 272 </span> } -<span id="L273" class="LineNr"> 273 </span> <span class="subxComment"># if (al == 0xb6) shift = false # right shift is being lifted</span> -<span id="L274" class="LineNr"> 274 </span> { -<span id="L275" class="LineNr"> 275 </span> 3c/compare-al-and 0xb6/imm8 -<span id="L276" class="LineNr"> 276 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L277" class="LineNr"> 277 </span> <span class="subxComment"># *shift = 0</span> -<span id="L278" class="LineNr"> 278 </span> c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32 -<span id="L279" class="LineNr"> 279 </span> } -<span id="L280" class="LineNr"> 280 </span> <span class="subxComment"># if (al == 0x9d) ctrl = false # ctrl is being lifted</span> -<span id="L281" class="LineNr"> 281 </span> { -<span id="L282" class="LineNr"> 282 </span> 3c/compare-al-and 0x9d/imm8 -<span id="L283" class="LineNr"> 283 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L284" class="LineNr"> 284 </span> <span class="subxComment"># *ctrl = 0</span> -<span id="L285" class="LineNr"> 285 </span> c7 0/subop/copy *Keyboard-ctrl-pressed? 0/imm32 -<span id="L286" class="LineNr"> 286 </span> } -<span id="L287" class="LineNr"> 287 </span> <span class="subxComment"># if (al & 0x80) a key is being lifted; return</span> -<span id="L288" class="LineNr"> 288 </span> 50/push-eax -<span id="L289" class="LineNr"> 289 </span> 24/and-al-with 0x80/imm8 -<span id="L290" class="LineNr"> 290 </span> 3c/compare-al-and 0/imm8 -<span id="L291" class="LineNr"> 291 </span> 58/pop-to-eax -<span id="L292" class="LineNr"> 292 </span> 75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8 -<span id="L293" class="LineNr"> 293 </span> <span class="subxH1Comment"># - key pressed</span> -<span id="L294" class="LineNr"> 294 </span> <span class="subxComment"># if (al == 0x2a) shift = true, return # left shift pressed</span> -<span id="L295" class="LineNr"> 295 </span> { -<span id="L296" class="LineNr"> 296 </span> 3c/compare-al-and 0x2a/imm8 -<span id="L297" class="LineNr"> 297 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L298" class="LineNr"> 298 </span> <span class="subxComment"># *shift = 1</span> -<span id="L299" class="LineNr"> 299 </span> c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32 -<span id="L300" class="LineNr"> 300 </span> <span class="subxComment"># return</span> -<span id="L301" class="LineNr"> 301 </span> eb/jump $keyboard-interrupt-handler:epilogue/disp8 -<span id="L302" class="LineNr"> 302 </span> } -<span id="L303" class="LineNr"> 303 </span> <span class="subxComment"># if (al == 0x36) shift = true, return # right shift pressed</span> -<span id="L304" class="LineNr"> 304 </span> { -<span id="L305" class="LineNr"> 305 </span> 3c/compare-al-and 0x36/imm8 -<span id="L306" class="LineNr"> 306 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L307" class="LineNr"> 307 </span> <span class="subxComment"># *shift = 1</span> -<span id="L308" class="LineNr"> 308 </span> c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32 -<span id="L309" class="LineNr"> 309 </span> <span class="subxComment"># return</span> -<span id="L310" class="LineNr"> 310 </span> eb/jump $keyboard-interrupt-handler:epilogue/disp8 -<span id="L311" class="LineNr"> 311 </span> } -<span id="L312" class="LineNr"> 312 </span> <span class="subxComment"># if (al == 0x1d) ctrl = true, return</span> -<span id="L313" class="LineNr"> 313 </span> { -<span id="L314" class="LineNr"> 314 </span> 3c/compare-al-and 0x1d/imm8 -<span id="L315" class="LineNr"> 315 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L316" class="LineNr"> 316 </span> <span class="subxComment"># *ctrl = 1</span> -<span id="L317" class="LineNr"> 317 </span> c7 0/subop/copy *Keyboard-ctrl-pressed? 1/imm32 -<span id="L318" class="LineNr"> 318 </span> <span class="subxComment"># return</span> -<span id="L319" class="LineNr"> 319 </span> eb/jump $keyboard-interrupt-handler:epilogue/disp8 -<span id="L320" class="LineNr"> 320 </span> } -<span id="L321" class="LineNr"> 321 </span> <span class="subxH1Comment"># - convert key to character</span> -<span id="L322" class="LineNr"> 322 </span> <span class="subxComment"># if (shift) use keyboard shift map</span> -<span id="L323" class="LineNr"> 323 </span> { -<span id="L324" class="LineNr"> 324 </span> 81 7/subop/compare *Keyboard-shift-pressed? 0/imm32 -<span id="L325" class="LineNr"> 325 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L326" class="LineNr"> 326 </span> <span class="subxComment"># sigils don't currently support labels inside *(eax+label)</span> -<span id="L327" class="LineNr"> 327 </span> 05/add-to-eax <span class="SpecialChar"><a href='boot.subx.html#L634'>Keyboard-shift-map</a></span>/imm32 -<span id="L328" class="LineNr"> 328 </span> 8a/byte-> *eax 0/r32/al -<span id="L329" class="LineNr"> 329 </span> eb/jump $keyboard-interrupt-handler:select-map-done/disp8 -<span id="L330" class="LineNr"> 330 </span> } -<span id="L331" class="LineNr"> 331 </span> <span class="subxComment"># if (ctrl) al = *(ctrl map + al)</span> -<span id="L332" class="LineNr"> 332 </span> { -<span id="L333" class="LineNr"> 333 </span> 81 7/subop/compare *Keyboard-ctrl-pressed? 0/imm32 -<span id="L334" class="LineNr"> 334 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L335" class="LineNr"> 335 </span> 05/add-to-eax <span class="SpecialChar"><a href='boot.subx.html#L661'>Keyboard-ctrl-map</a></span>/imm32 -<span id="L336" class="LineNr"> 336 </span> 8a/byte-> *eax 0/r32/al -<span id="L337" class="LineNr"> 337 </span> eb/jump $keyboard-interrupt-handler:select-map-done/disp8 -<span id="L338" class="LineNr"> 338 </span> } -<span id="L339" class="LineNr"> 339 </span> <span class="subxComment"># otherwise al = *(normal map + al)</span> -<span id="L340" class="LineNr"> 340 </span> 05/add-to-eax <span class="SpecialChar"><a href='boot.subx.html#L605'>Keyboard-normal-map</a></span>/imm32 -<span id="L341" class="LineNr"> 341 </span> 8a/byte-> *eax 0/r32/al -<span id="L342" class="LineNr"> 342 </span><span class="Constant">$keyboard-interrupt-handler:select-map-done</span>: -<span id="L343" class="LineNr"> 343 </span> <span class="subxH1Comment"># - if there's no character mapping, return</span> -<span id="L344" class="LineNr"> 344 </span> { -<span id="L345" class="LineNr"> 345 </span> 3c/compare-al-and 0/imm8 -<span id="L346" class="LineNr"> 346 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L347" class="LineNr"> 347 </span> <span class="subxH1Comment"># - store al in keyboard buffer</span> -<span id="L348" class="LineNr"> 348 </span> 88/<- *ecx 0/r32/al -<span id="L349" class="LineNr"> 349 </span> <span class="subxComment"># increment index</span> -<span id="L350" class="LineNr"> 350 </span> fe/increment-byte *<span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a> -<span id="L351" class="LineNr"> 351 </span> <span class="subxComment"># clear top nibble of index (keyboard buffer is circular)</span> -<span id="L352" class="LineNr"> 352 </span> 80 4/subop/and-byte *<span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a> 0x0f/imm8 -<span id="L353" class="LineNr"> 353 </span> } -<span id="L354" class="LineNr"> 354 </span><span class="Constant">$keyboard-interrupt-handler:epilogue</span>: -<span id="L355" class="LineNr"> 355 </span> <span class="subxComment"># epilogue</span> -<span id="L356" class="LineNr"> 356 </span> 61/pop-all-registers -<span id="L357" class="LineNr"> 357 </span> fb/enable-interrupts -<span id="L358" class="LineNr"> 358 </span> cf/return-from-interrupt -<span id="L359" class="LineNr"> 359 </span> -<span id="L360" class="LineNr"> 360 </span><span class="subxComment">## the rest of this file is all data</span> -<span id="L361" class="LineNr"> 361 </span> -<span id="L362" class="LineNr"> 362 </span>== data 0x8000 -<span id="L363" class="LineNr"> 363 </span><span class="subxFunction">idt_descriptor</span>: -<span id="L364" class="LineNr"> 364 </span> ff 03 <span class="subxComment"># final index of idt = size of idt - 1</span> -<span id="L365" class="LineNr"> 365 </span> <a href='boot.subx.html#L443'>idt_start</a>/imm32/start -<span id="L366" class="LineNr"> 366 </span> -<span id="L367" class="LineNr"> 367 </span>Keyboard-shift-pressed?: <span class="subxComment"># boolean</span> -<span id="L368" class="LineNr"> 368 </span> 0/imm32 -<span id="L369" class="LineNr"> 369 </span> -<span id="L370" class="LineNr"> 370 </span>Keyboard-ctrl-pressed?: <span class="subxComment"># boolean</span> -<span id="L371" class="LineNr"> 371 </span> 0/imm32 -<span id="L372" class="LineNr"> 372 </span> -<span id="L373" class="LineNr"> 373 </span><span class="subxComment"># var keyboard circular buffer</span> -<span id="L374" class="LineNr"> 374 </span><span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a>: <span class="subxComment"># nibble</span> -<span id="L375" class="LineNr"> 375 </span> 0/imm32 -<span id="L376" class="LineNr"> 376 </span><span class="SpecialChar">Keyboard-buffer</span>:read: <span class="subxComment"># nibble</span> -<span id="L377" class="LineNr"> 377 </span> 0/imm32 -<span id="L378" class="LineNr"> 378 </span><span class="SpecialChar">Keyboard-buffer</span>:data: <span class="subxComment"># byte[16]</span> -<span id="L379" class="LineNr"> 379 </span> 00 00 00 00 -<span id="L380" class="LineNr"> 380 </span> 00 00 00 00 -<span id="L381" class="LineNr"> 381 </span> 00 00 00 00 -<span id="L382" class="LineNr"> 382 </span> 00 00 00 00 -<span id="L383" class="LineNr"> 383 </span> -<span id="L384" class="LineNr"> 384 </span>== data 0x8100 -<span id="L385" class="LineNr"> 385 </span><span class="SpecialChar">Video-mode-info</span>: -<span id="L386" class="Folded"> 386 </span><span class="Folded">+-- 53 lines: # video mode info ---------------------------------------------------------------------------------------------------------------------------------------------------------</span> -<span id="L439" class="LineNr"> 439 </span> -<span id="L440" class="LineNr"> 440 </span>== data 0x8200 -<span id="L441" class="Folded"> 441 </span><span class="Folded">+--161 lines: # interrupt descriptor table ----------------------------------------------------------------------------------------------------------------------------------------------</span> -<span id="L602" class="LineNr"> 602 </span> -<span id="L603" class="LineNr"> 603 </span>== data 0x8600 -<span id="L604" class="Folded"> 604 </span><span class="Folded">+-- 72 lines: # translating keys to ASCII -----------------------------------------------------------------------------------------------------------------------------------------------</span> -<span id="L676" class="LineNr"> 676 </span> -<span id="L677" class="LineNr"> 677 </span>== data 0x8c00 -<span id="L678" class="LineNr"> 678 </span><span class="SpecialChar">Font</span>: -<span id="L679" class="Folded"> 679 </span><span class="Folded">+--236 lines: # Bitmaps for some ASCII characters (soon Unicode) ------------------------------------------------------------------------------------------------------------------------</span> -<span id="L915" class="LineNr"> 915 </span> -<span id="L916" class="LineNr"> 916 </span><span class="subxComment"># offset 1800 (address 0x9400)</span> -<span id="L917" class="LineNr"> 917 </span>== code 0x9400 -<span id="L918" class="LineNr"> 918 </span> -<span id="L919" class="LineNr"> 919 </span><span class="subxComment"># Use 28-bit PIO mode to read the first sector (512 bytes) from an IDE (ATA)</span> -<span id="L920" class="LineNr"> 920 </span><span class="subxComment"># disk drive.</span> -<span id="L921" class="LineNr"> 921 </span><span class="subxComment"># Inspired by <a href="https://colorforth.github.io/ide.html">https://colorforth.github.io/ide.html</a></span> -<span id="L922" class="LineNr"> 922 </span><span class="subxComment">#</span> -<span id="L923" class="LineNr"> 923 </span><span class="subxComment"># Resources:</span> -<span id="L924" class="LineNr"> 924 </span><span class="subxComment"># <a href="https://wiki.osdev.org/ATA_PIO_Mode">https://wiki.osdev.org/ATA_PIO_Mode</a></span> -<span id="L925" class="LineNr"> 925 </span><span class="subxComment"># <a href="https://forum.osdev.org/viewtopic.php?f=1&p=167798">https://forum.osdev.org/viewtopic.php?f=1&p=167798</a></span> -<span id="L926" class="LineNr"> 926 </span><span class="subxComment"># read-sector, according to <a href="https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf">https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf</a></span> -<span id="L927" class="LineNr"> 927 </span><span class="subxFunction">load-first-sector-from-primary-bus-secondary-drive</span>: <span class="subxComment"># out: (addr stream byte)</span> -<span id="L928" class="LineNr"> 928 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L929" class="LineNr"> 929 </span> 55/push-ebp -<span id="L930" class="LineNr"> 930 </span> 89/<- %ebp 4/r32/esp -<span id="L931" class="LineNr"> 931 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L932" class="LineNr"> 932 </span> 50/push-eax -<span id="L933" class="LineNr"> 933 </span> 51/push-ecx -<span id="L934" class="LineNr"> 934 </span> 52/push-edx -<span id="L935" class="LineNr"> 935 </span> <span class="subxComment"># check for drive</span> -<span id="L936" class="LineNr"> 936 </span> (<a href='boot.subx.html#L1059'>secondary-drive-exists?</a>) <span class="subxComment"># => eax</span> -<span id="L937" class="LineNr"> 937 </span> 3d/compare-eax-and 0/imm32/false -<span id="L938" class="LineNr"> 938 </span> 0f 84/jump-if-= $load-first-sector-from-primary-bus-secondary-drive:end/disp32 -<span id="L939" class="LineNr"> 939 </span> <span class="subxComment"># kick off read</span> -<span id="L940" class="LineNr"> 940 </span> (<a href='boot.subx.html#L1119'>ata-drive-select</a> 0xf0) <span class="subxComment"># primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0)</span> -<span id="L941" class="LineNr"> 941 </span> (<a href='boot.subx.html#L1139'>clear-ata-error</a>) -<span id="L942" class="LineNr"> 942 </span> (<a href='boot.subx.html#L1159'>ata-sector-count</a> 1) -<span id="L943" class="LineNr"> 943 </span> (<a href='boot.subx.html#L1179'>ata-lba</a> 0 0 0) <span class="subxComment"># lower 24 bits of LBA, all 0</span> -<span id="L944" class="LineNr"> 944 </span> (<a href='boot.subx.html#L1237'>ata-command</a> 0x20) <span class="subxComment"># read sectors with retries</span> -<span id="L945" class="LineNr"> 945 </span> <span class="subxComment"># poll for results</span> -<span id="L946" class="LineNr"> 946 </span> (<a href='boot.subx.html#L1257'>while-ata-busy</a>) -<span id="L947" class="LineNr"> 947 </span> (<a href='boot.subx.html#L1275'>until-ata-data-available</a>) -<span id="L948" class="LineNr"> 948 </span> <span class="subxComment"># emit results</span> -<span id="L949" class="LineNr"> 949 </span> 31/xor %eax 0/r32/eax -<span id="L950" class="LineNr"> 950 </span> ba/copy-to-edx 0x1f0/imm32 -<span id="L951" class="LineNr"> 951 </span> b9/copy-to-ecx 0x200/imm32 <span class="subxComment"># 512 bytes per sector</span> -<span id="L952" class="LineNr"> 952 </span> { -<span id="L953" class="LineNr"> 953 </span> 81 7/subop/compare %ecx 0/imm32 -<span id="L954" class="LineNr"> 954 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L955" class="LineNr"> 955 </span> 66 ed/read-port-dx-into-ax -<span id="L956" class="LineNr"> 956 </span> <span class="subxComment"># write 2 bytes to stream one at a time</span> -<span id="L957" class="LineNr"> 957 </span> (<a href='115write-byte.subx.html#L12'>append-byte</a> *(ebp+8) %eax) -<span id="L958" class="LineNr"> 958 </span> 49/decrement-ecx -<span id="L959" class="LineNr"> 959 </span> c1/shift 5/subop/right-padding-zeroes %eax 8/imm8 -<span id="L960" class="LineNr"> 960 </span> (<a href='115write-byte.subx.html#L12'>append-byte</a> *(ebp+8) %eax) -<span id="L961" class="LineNr"> 961 </span> 49/decrement-ecx -<span id="L962" class="LineNr"> 962 </span> eb/jump <span class="Constant">loop</span>/disp8 -<span id="L963" class="LineNr"> 963 </span> } -<span id="L964" class="LineNr"> 964 </span><span class="Constant">$load-first-sector-from-primary-bus-secondary-drive:end</span>: -<span id="L965" class="LineNr"> 965 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L966" class="LineNr"> 966 </span> 5a/pop-to-edx -<span id="L967" class="LineNr"> 967 </span> 59/pop-to-ecx -<span id="L968" class="LineNr"> 968 </span> 58/pop-to-eax -<span id="L969" class="LineNr"> 969 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L970" class="LineNr"> 970 </span> 89/<- %esp 5/r32/ebp -<span id="L971" class="LineNr"> 971 </span> 5d/pop-to-ebp -<span id="L972" class="LineNr"> 972 </span> c3/return -<span id="L973" class="LineNr"> 973 </span> -<span id="L974" class="LineNr"> 974 </span><span class="subxFunction">store-first-sector-to-primary-bus-secondary-drive</span>: <span class="subxComment"># in: (addr stream byte)</span> -<span id="L975" class="LineNr"> 975 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L976" class="LineNr"> 976 </span> 55/push-ebp -<span id="L977" class="LineNr"> 977 </span> 89/<- %ebp 4/r32/esp -<span id="L978" class="LineNr"> 978 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L979" class="LineNr"> 979 </span> 50/push-eax -<span id="L980" class="LineNr"> 980 </span> 51/push-ecx -<span id="L981" class="LineNr"> 981 </span> 52/push-edx -<span id="L982" class="LineNr"> 982 </span> 53/push-ebx -<span id="L983" class="LineNr"> 983 </span> <span class="subxComment"># check for drive</span> -<span id="L984" class="LineNr"> 984 </span> (<a href='boot.subx.html#L1059'>secondary-drive-exists?</a>) <span class="subxComment"># => eax</span> -<span id="L985" class="LineNr"> 985 </span> 3d/compare-eax-and 0/imm32/false -<span id="L986" class="LineNr"> 986 </span> 0f 84/jump-if-= $store-first-sector-to-primary-bus-secondary-drive:end/disp32 -<span id="L987" class="LineNr"> 987 </span> <span class="subxComment"># kick off write</span> -<span id="L988" class="LineNr"> 988 </span> (<a href='boot.subx.html#L1119'>ata-drive-select</a> 0xf0) <span class="subxComment"># primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0)</span> -<span id="L989" class="LineNr"> 989 </span> (<a href='boot.subx.html#L1139'>clear-ata-error</a>) -<span id="L990" class="LineNr"> 990 </span> (<a href='boot.subx.html#L1159'>ata-sector-count</a> 1) -<span id="L991" class="LineNr"> 991 </span> (<a href='boot.subx.html#L1179'>ata-lba</a> 0 0 0) <span class="subxComment"># lower 24 bits of LBA, all 0</span> -<span id="L992" class="LineNr"> 992 </span> (<a href='boot.subx.html#L1237'>ata-command</a> 0x30) <span class="subxComment"># write sectors with retries</span> -<span id="L993" class="LineNr"> 993 </span> <span class="subxComment"># wait</span> -<span id="L994" class="LineNr"> 994 </span> (<a href='boot.subx.html#L1257'>while-ata-busy</a>) -<span id="L995" class="LineNr"> 995 </span> (<a href='boot.subx.html#L1293'>until-ata-ready-for-data</a>) -<span id="L996" class="LineNr"> 996 </span> <span class="subxComment"># send data</span> -<span id="L997" class="LineNr"> 997 </span> ba/copy-to-edx 0x1f0/imm32 -<span id="L998" class="LineNr"> 998 </span> b9/copy-to-ecx 0x200/imm32 <span class="subxComment"># 512 bytes per sector</span> -<span id="L999" class="LineNr"> 999 </span> <span class="subxComment"># var first-byte/ebx: byte</span> -<span id="L1000" class="LineNr">1000 </span> <span class="subxComment"># when it's more than 0xff, we're at an even-numbered byte</span> -<span id="L1001" class="LineNr">1001 </span> bb/copy-to-ebx 0xffff/imm32 -<span id="L1002" class="LineNr">1002 </span><span class="Constant">$store-first-sector-to-primary-bus-secondary-drive:loop</span>: -<span id="L1003" class="LineNr">1003 </span> { -<span id="L1004" class="LineNr">1004 </span> 81 7/subop/compare %ecx 0/imm32 -<span id="L1005" class="LineNr">1005 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L1006" class="LineNr">1006 </span> <span class="subxComment"># this loop is slow, but the ATA spec also requires a small delay</span> -<span id="L1007" class="LineNr">1007 </span> (<a href='309stream.subx.html#L6'>stream-empty?</a> *(ebp+8)) <span class="subxComment"># => eax</span> -<span id="L1008" class="LineNr">1008 </span> 3d/compare-eax-and 0/imm32/false -<span id="L1009" class="LineNr">1009 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L1010" class="LineNr">1010 </span> <span class="subxComment"># read byte from stream</span> -<span id="L1011" class="LineNr">1011 </span> (<a href='112read-byte.subx.html#L13'>read-byte</a> *(ebp+8)) <span class="subxComment"># => eax</span> -<span id="L1012" class="LineNr">1012 </span> <span class="subxComment"># if we're at an odd-numbered byte, save it to first-byte</span> -<span id="L1013" class="LineNr">1013 </span> 81 7/subop/compare %ebx 0xff/imm32 -<span id="L1014" class="LineNr">1014 </span> { -<span id="L1015" class="LineNr">1015 </span> 7e/jump-if-<= <span class="Constant">break</span>/disp8 -<span id="L1016" class="LineNr">1016 </span> 89/<- %ebx 0/r32/eax -<span id="L1017" class="LineNr">1017 </span> eb/jump $store-first-sector-to-primary-bus-secondary-drive:<span class="Constant">loop</span>/disp8 -<span id="L1018" class="LineNr">1018 </span> } -<span id="L1019" class="LineNr">1019 </span> <span class="subxComment"># otherwise OR it with first-byte and write it out</span> -<span id="L1020" class="LineNr">1020 </span> c1/shift 4/subop/left %eax 8/imm8 -<span id="L1021" class="LineNr">1021 </span> 09/or %eax 3/r32/ebx -<span id="L1022" class="LineNr">1022 </span> 66 ef/write-ax-into-port-dx -<span id="L1023" class="LineNr">1023 </span> 49/decrement-ecx -<span id="L1024" class="LineNr">1024 </span> 49/decrement-ecx -<span id="L1025" class="LineNr">1025 </span> <span class="subxComment"># reset first-byte</span> -<span id="L1026" class="LineNr">1026 </span> bb/copy-to-ebx 0xffff/imm32 -<span id="L1027" class="LineNr">1027 </span> eb/jump <span class="Constant">loop</span>/disp8 -<span id="L1028" class="LineNr">1028 </span> } -<span id="L1029" class="LineNr">1029 </span> <span class="subxComment"># write out first-byte if necessary</span> -<span id="L1030" class="LineNr">1030 </span> 81 7/subop/compare %ebx 0xff/imm32 -<span id="L1031" class="LineNr">1031 </span> { -<span id="L1032" class="LineNr">1032 </span> 7f/jump-if-> <span class="Constant">break</span>/disp8 -<span id="L1033" class="LineNr">1033 </span> 89/<- %eax 3/r32/ebx -<span id="L1034" class="LineNr">1034 </span> 66 ef/write-ax-into-port-dx -<span id="L1035" class="LineNr">1035 </span> 49/decrement-ecx -<span id="L1036" class="LineNr">1036 </span> 49/decrement-ecx -<span id="L1037" class="LineNr">1037 </span> } -<span id="L1038" class="LineNr">1038 </span> <span class="subxComment"># pad zeroes</span> -<span id="L1039" class="LineNr">1039 </span> 31/xor %eax 0/r32/eax -<span id="L1040" class="LineNr">1040 </span> { -<span id="L1041" class="LineNr">1041 </span> 81 7/subop/compare %ecx 0/imm32 -<span id="L1042" class="LineNr">1042 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L1043" class="LineNr">1043 </span> 66 ef/write-ax-into-port-dx -<span id="L1044" class="LineNr">1044 </span> 49/decrement-ecx -<span id="L1045" class="LineNr">1045 </span> 49/decrement-ecx -<span id="L1046" class="LineNr">1046 </span> eb/jump <span class="Constant">loop</span>/disp8 -<span id="L1047" class="LineNr">1047 </span> } -<span id="L1048" class="LineNr">1048 </span><span class="Constant">$store-first-sector-to-primary-bus-secondary-drive:end</span>: -<span id="L1049" class="LineNr">1049 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1050" class="LineNr">1050 </span> 5b/pop-to-ebx -<span id="L1051" class="LineNr">1051 </span> 5a/pop-to-edx -<span id="L1052" class="LineNr">1052 </span> 59/pop-to-ecx -<span id="L1053" class="LineNr">1053 </span> 58/pop-to-eax -<span id="L1054" class="LineNr">1054 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1055" class="LineNr">1055 </span> 89/<- %esp 5/r32/ebp -<span id="L1056" class="LineNr">1056 </span> 5d/pop-to-ebp -<span id="L1057" class="LineNr">1057 </span> c3/return -<span id="L1058" class="LineNr">1058 </span> -<span id="L1059" class="LineNr">1059 </span><span class="subxFunction">secondary-drive-exists?</span>: <span class="subxComment"># -> _/eax: boolean</span> -<span id="L1060" class="LineNr">1060 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1061" class="LineNr">1061 </span> 55/push-ebp -<span id="L1062" class="LineNr">1062 </span> 89/<- %ebp 4/r32/esp -<span id="L1063" class="LineNr">1063 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1064" class="LineNr">1064 </span> 52/push-edx -<span id="L1065" class="LineNr">1065 </span> <span class="subxComment"># check for floating bus</span> -<span id="L1066" class="LineNr">1066 </span> { -<span id="L1067" class="LineNr">1067 </span> 31/xor %eax 0/r32/eax -<span id="L1068" class="LineNr">1068 </span> ba/copy-to-edx 0x1f7/imm32 -<span id="L1069" class="LineNr">1069 </span> ec/read-port-dx-into-al -<span id="L1070" class="LineNr">1070 </span> 3d/compare-eax-and 0xff/imm32 -<span id="L1071" class="LineNr">1071 </span> <span class="subxComment"># if eax is 0xff, primary bus has no drives</span> -<span id="L1072" class="LineNr">1072 </span> b8/copy-to-eax 0/imm32/false -<span id="L1073" class="LineNr">1073 </span> 74/jump-if-= $secondary-drive-exists?:end/disp8 -<span id="L1074" class="LineNr">1074 </span> } -<span id="L1075" class="LineNr">1075 </span> <span class="subxComment"># identify</span> -<span id="L1076" class="LineNr">1076 </span> (<a href='boot.subx.html#L1119'>ata-drive-select</a> 0xb0) <span class="subxComment"># primary bus, secondary drive</span> -<span id="L1077" class="LineNr">1077 </span> (<a href='boot.subx.html#L1159'>ata-sector-count</a> 0) -<span id="L1078" class="LineNr">1078 </span> (<a href='boot.subx.html#L1179'>ata-lba</a> 0 0 0) -<span id="L1079" class="LineNr">1079 </span> (<a href='boot.subx.html#L1237'>ata-command</a> 0xec) <span class="subxComment"># identify</span> -<span id="L1080" class="LineNr">1080 </span> <span class="subxComment"># read status register</span> -<span id="L1081" class="LineNr">1081 </span> <span class="subxComment"># TODO: might need to spin here for 400ns: <a href="https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#400ns_delays">https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#400ns_delays</a></span> -<span id="L1082" class="LineNr">1082 </span> 31/xor %eax 0/r32/eax -<span id="L1083" class="LineNr">1083 </span> ba/copy-to-edx 0x1f7/imm32 -<span id="L1084" class="LineNr">1084 </span> ec/read-port-dx-into-al -<span id="L1085" class="LineNr">1085 </span> <span class="subxComment"># if eax is 0, secondary drive does not exist</span> -<span id="L1086" class="LineNr">1086 </span> 3d/compare-eax-and 0/imm32 -<span id="L1087" class="LineNr">1087 </span> { -<span id="L1088" class="LineNr">1088 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L1089" class="LineNr">1089 </span> b8/copy-to-eax 1/imm32/true -<span id="L1090" class="LineNr">1090 </span> eb/jump $secondary-drive-exists?:complete-identify/disp8 -<span id="L1091" class="LineNr">1091 </span> } -<span id="L1092" class="LineNr">1092 </span> <span class="subxComment"># TODO: might need to perform remaining steps at <a href="https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#IDENTIFY_command">https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#IDENTIFY_command</a></span> -<span id="L1093" class="LineNr">1093 </span> b8/copy-to-eax 0/imm32/false -<span id="L1094" class="LineNr">1094 </span><span class="Constant">$secondary-drive-exists?:complete-identify</span>: -<span id="L1095" class="LineNr">1095 </span> 50/push-eax -<span id="L1096" class="LineNr">1096 </span> <span class="subxComment"># clear FIFO from the drive</span> -<span id="L1097" class="LineNr">1097 </span> ba/copy-to-edx 0x1f0/imm32 -<span id="L1098" class="LineNr">1098 </span> b9/copy-to-ecx 0x200/imm32 -<span id="L1099" class="LineNr">1099 </span> { -<span id="L1100" class="LineNr">1100 </span> 81 7/subop/compare %ecx 0/imm32 -<span id="L1101" class="LineNr">1101 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L1102" class="LineNr">1102 </span> <span class="subxComment"># read 4 bytes</span> -<span id="L1103" class="LineNr">1103 </span> ed/read-port-dx-into-eax -<span id="L1104" class="LineNr">1104 </span> 49/decrement-ecx -<span id="L1105" class="LineNr">1105 </span> 49/decrement-ecx -<span id="L1106" class="LineNr">1106 </span> 49/decrement-ecx -<span id="L1107" class="LineNr">1107 </span> 49/decrement-ecx -<span id="L1108" class="LineNr">1108 </span> eb/jump <span class="Constant">loop</span>/disp8 -<span id="L1109" class="LineNr">1109 </span> } -<span id="L1110" class="LineNr">1110 </span> 58/pop-to-eax -<span id="L1111" class="LineNr">1111 </span><span class="Constant">$secondary-drive-exists?:end</span>: -<span id="L1112" class="LineNr">1112 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1113" class="LineNr">1113 </span> 5a/pop-to-edx -<span id="L1114" class="LineNr">1114 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1115" class="LineNr">1115 </span> 89/<- %esp 5/r32/ebp -<span id="L1116" class="LineNr">1116 </span> 5d/pop-to-ebp -<span id="L1117" class="LineNr">1117 </span> c3/return -<span id="L1118" class="LineNr">1118 </span> -<span id="L1119" class="LineNr">1119 </span><span class="subxFunction">ata-drive-select</span>: <span class="subxComment"># n: byte</span> -<span id="L1120" class="LineNr">1120 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1121" class="LineNr">1121 </span> 55/push-ebp -<span id="L1122" class="LineNr">1122 </span> 89/<- %ebp 4/r32/esp -<span id="L1123" class="LineNr">1123 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1124" class="LineNr">1124 </span> 50/push-eax -<span id="L1125" class="LineNr">1125 </span> 52/push-edx -<span id="L1126" class="LineNr">1126 </span> <span class="subxComment">#</span> -<span id="L1127" class="LineNr">1127 </span> 8b/-> *(ebp+8) 0/r32/eax -<span id="L1128" class="LineNr">1128 </span> ba/copy-to-edx 0x1f6/imm32 -<span id="L1129" class="LineNr">1129 </span> ee/write-al-into-port-dx -<span id="L1130" class="LineNr">1130 </span><span class="Constant">$ata-drive-select:end</span>: -<span id="L1131" class="LineNr">1131 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1132" class="LineNr">1132 </span> 5a/pop-to-edx -<span id="L1133" class="LineNr">1133 </span> 58/pop-to-eax -<span id="L1134" class="LineNr">1134 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1135" class="LineNr">1135 </span> 89/<- %esp 5/r32/ebp -<span id="L1136" class="LineNr">1136 </span> 5d/pop-to-ebp -<span id="L1137" class="LineNr">1137 </span> c3/return -<span id="L1138" class="LineNr">1138 </span> -<span id="L1139" class="LineNr">1139 </span><span class="subxFunction">clear-ata-error</span>: -<span id="L1140" class="LineNr">1140 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1141" class="LineNr">1141 </span> 55/push-ebp -<span id="L1142" class="LineNr">1142 </span> 89/<- %ebp 4/r32/esp -<span id="L1143" class="LineNr">1143 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1144" class="LineNr">1144 </span> 50/push-eax -<span id="L1145" class="LineNr">1145 </span> 52/push-edx -<span id="L1146" class="LineNr">1146 </span> <span class="subxComment">#</span> -<span id="L1147" class="LineNr">1147 </span> b8/copy-to-eax 0/imm32 -<span id="L1148" class="LineNr">1148 </span> ba/copy-to-edx 0x1f1/imm32 -<span id="L1149" class="LineNr">1149 </span> ee/write-al-into-port-dx -<span id="L1150" class="LineNr">1150 </span><span class="Constant">$ata-error:end</span>: -<span id="L1151" class="LineNr">1151 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1152" class="LineNr">1152 </span> 5a/pop-to-edx -<span id="L1153" class="LineNr">1153 </span> 58/pop-to-eax -<span id="L1154" class="LineNr">1154 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1155" class="LineNr">1155 </span> 89/<- %esp 5/r32/ebp -<span id="L1156" class="LineNr">1156 </span> 5d/pop-to-ebp -<span id="L1157" class="LineNr">1157 </span> c3/return -<span id="L1158" class="LineNr">1158 </span> -<span id="L1159" class="LineNr">1159 </span><span class="subxFunction">ata-sector-count</span>: <span class="subxComment"># n: byte</span> -<span id="L1160" class="LineNr">1160 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1161" class="LineNr">1161 </span> 55/push-ebp -<span id="L1162" class="LineNr">1162 </span> 89/<- %ebp 4/r32/esp -<span id="L1163" class="LineNr">1163 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1164" class="LineNr">1164 </span> 50/push-eax -<span id="L1165" class="LineNr">1165 </span> 52/push-edx -<span id="L1166" class="LineNr">1166 </span> <span class="subxComment">#</span> -<span id="L1167" class="LineNr">1167 </span> 8b/-> *(ebp+8) 0/r32/eax -<span id="L1168" class="LineNr">1168 </span> ba/copy-to-edx 0x1f2/imm32 -<span id="L1169" class="LineNr">1169 </span> ee/write-al-into-port-dx -<span id="L1170" class="LineNr">1170 </span><span class="Constant">$ata-sector-count:end</span>: -<span id="L1171" class="LineNr">1171 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1172" class="LineNr">1172 </span> 5a/pop-to-edx -<span id="L1173" class="LineNr">1173 </span> 58/pop-to-eax -<span id="L1174" class="LineNr">1174 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1175" class="LineNr">1175 </span> 89/<- %esp 5/r32/ebp -<span id="L1176" class="LineNr">1176 </span> 5d/pop-to-ebp -<span id="L1177" class="LineNr">1177 </span> c3/return -<span id="L1178" class="LineNr">1178 </span> -<span id="L1179" class="LineNr">1179 </span><span class="subxFunction">ata-lba</span>: <span class="subxComment"># lo: byte, mid: byte, hi: byte</span> -<span id="L1180" class="LineNr">1180 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1181" class="LineNr">1181 </span> 55/push-ebp -<span id="L1182" class="LineNr">1182 </span> 89/<- %ebp 4/r32/esp -<span id="L1183" class="LineNr">1183 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1184" class="LineNr">1184 </span> 50/push-eax -<span id="L1185" class="LineNr">1185 </span> 52/push-edx -<span id="L1186" class="LineNr">1186 </span> <span class="subxComment"># lo</span> -<span id="L1187" class="LineNr">1187 </span> 8b/-> *(ebp+8) 0/r32/eax -<span id="L1188" class="LineNr">1188 </span> ba/copy-to-edx 0x1f3/imm32 -<span id="L1189" class="LineNr">1189 </span> ee/write-al-into-port-dx -<span id="L1190" class="LineNr">1190 </span> <span class="subxComment"># mid</span> -<span id="L1191" class="LineNr">1191 </span> 8b/-> *(ebp+0xc) 0/r32/eax -<span id="L1192" class="LineNr">1192 </span> ba/copy-to-edx 0x1f4/imm32 -<span id="L1193" class="LineNr">1193 </span> ee/write-al-into-port-dx -<span id="L1194" class="LineNr">1194 </span> <span class="subxComment"># hi</span> -<span id="L1195" class="LineNr">1195 </span> 8b/-> *(ebp+0x10) 0/r32/eax -<span id="L1196" class="LineNr">1196 </span> ba/copy-to-edx 0x1f5/imm32 -<span id="L1197" class="LineNr">1197 </span> ee/write-al-into-port-dx -<span id="L1198" class="LineNr">1198 </span><span class="Constant">$ata-lba:end</span>: -<span id="L1199" class="LineNr">1199 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1200" class="LineNr">1200 </span> 5a/pop-to-edx -<span id="L1201" class="LineNr">1201 </span> 58/pop-to-eax -<span id="L1202" class="LineNr">1202 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1203" class="LineNr">1203 </span> 89/<- %esp 5/r32/ebp -<span id="L1204" class="LineNr">1204 </span> 5d/pop-to-ebp -<span id="L1205" class="LineNr">1205 </span> c3/return -<span id="L1206" class="LineNr">1206 </span> -<span id="L1207" class="LineNr">1207 </span><span class="subxComment"># sector: [1, 63]</span> -<span id="L1208" class="LineNr">1208 </span><span class="subxComment"># cylinder: [0, 1023]</span> -<span id="L1209" class="LineNr">1209 </span><span class="subxFunction">ata-cyl-sector</span>: <span class="subxComment"># sector: byte, cyl-lo: byte, cyl-hi: byte</span> -<span id="L1210" class="LineNr">1210 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1211" class="LineNr">1211 </span> 55/push-ebp -<span id="L1212" class="LineNr">1212 </span> 89/<- %ebp 4/r32/esp -<span id="L1213" class="LineNr">1213 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1214" class="LineNr">1214 </span> 50/push-eax -<span id="L1215" class="LineNr">1215 </span> 52/push-edx -<span id="L1216" class="LineNr">1216 </span> <span class="subxComment"># sector</span> -<span id="L1217" class="LineNr">1217 </span> 8b/-> *(ebp+8) 0/r32/eax -<span id="L1218" class="LineNr">1218 </span> ba/copy-to-edx 0x1f3/imm32 -<span id="L1219" class="LineNr">1219 </span> ee/write-al-into-port-dx -<span id="L1220" class="LineNr">1220 </span> <span class="subxComment"># cyl-lo</span> -<span id="L1221" class="LineNr">1221 </span> 8b/-> *(ebp+0xc) 0/r32/eax -<span id="L1222" class="LineNr">1222 </span> ba/copy-to-edx 0x1f4/imm32 -<span id="L1223" class="LineNr">1223 </span> ee/write-al-into-port-dx -<span id="L1224" class="LineNr">1224 </span> <span class="subxComment"># cyl-hi</span> -<span id="L1225" class="LineNr">1225 </span> 8b/-> *(ebp+0x10) 0/r32/eax -<span id="L1226" class="LineNr">1226 </span> ba/copy-to-edx 0x1f5/imm32 -<span id="L1227" class="LineNr">1227 </span> ee/write-al-into-port-dx -<span id="L1228" class="LineNr">1228 </span><span class="Constant">$ata-lba:end</span>: -<span id="L1229" class="LineNr">1229 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1230" class="LineNr">1230 </span> 5a/pop-to-edx -<span id="L1231" class="LineNr">1231 </span> 58/pop-to-eax -<span id="L1232" class="LineNr">1232 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1233" class="LineNr">1233 </span> 89/<- %esp 5/r32/ebp -<span id="L1234" class="LineNr">1234 </span> 5d/pop-to-ebp -<span id="L1235" class="LineNr">1235 </span> c3/return -<span id="L1236" class="LineNr">1236 </span> -<span id="L1237" class="LineNr">1237 </span><span class="subxFunction">ata-command</span>: <span class="subxComment"># cmd: byte</span> -<span id="L1238" class="LineNr">1238 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L1239" class="LineNr">1239 </span> 55/push-ebp -<span id="L1240" class="LineNr">1240 </span> 89/<- %ebp 4/r32/esp -<span id="L1241" class="LineNr">1241 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1242" class="LineNr">1242 </span> 50/push-eax -<span id="L1243" class="LineNr">1243 </span> 52/push-edx -<span id="L1244" class="LineNr">1244 </span> <span class="subxComment">#</span> -<span id="L1245" class="LineNr">1245 </span> 8b/-> *(ebp+8) 0/r32/eax -<span id="L1246" class="LineNr">1246 </span> ba/copy-to-edx 0x1f7/imm32 -<span id="L1247" class="LineNr">1247 </span> ee/write-al-into-port-dx -<span id="L1248" class="LineNr">1248 </span><span class="Constant">$ata-command:end</span>: -<span id="L1249" class="LineNr">1249 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1250" class="LineNr">1250 </span> 5a/pop-to-edx -<span id="L1251" class="LineNr">1251 </span> 58/pop-to-eax -<span id="L1252" class="LineNr">1252 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1253" class="LineNr">1253 </span> 89/<- %esp 5/r32/ebp -<span id="L1254" class="LineNr">1254 </span> 5d/pop-to-ebp -<span id="L1255" class="LineNr">1255 </span> c3/return -<span id="L1256" class="LineNr">1256 </span> -<span id="L1257" class="LineNr">1257 </span><span class="subxFunction">while-ata-busy</span>: -<span id="L1258" class="LineNr">1258 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1259" class="LineNr">1259 </span> 50/push-eax -<span id="L1260" class="LineNr">1260 </span> 52/push-edx -<span id="L1261" class="LineNr">1261 </span> <span class="subxComment">#</span> -<span id="L1262" class="LineNr">1262 </span> ba/copy-to-edx 0x1f7/imm32 -<span id="L1263" class="LineNr">1263 </span> { -<span id="L1264" class="LineNr">1264 </span> ec/read-port-dx-into-al -<span id="L1265" class="LineNr">1265 </span> a8/test-bits-in-al 0x80/imm8/bsy <span class="subxComment"># set zf if bit 7 (most significant) is not set</span> -<span id="L1266" class="LineNr">1266 </span> 75/jump-if-zf-not-set-and-bit-7-set <span class="Constant">loop</span>/disp8 -<span id="L1267" class="LineNr">1267 </span> } -<span id="L1268" class="LineNr">1268 </span><span class="Constant">$while-ata-busy:end</span>: -<span id="L1269" class="LineNr">1269 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1270" class="LineNr">1270 </span> 5a/pop-to-edx -<span id="L1271" class="LineNr">1271 </span> 58/pop-to-eax -<span id="L1272" class="LineNr">1272 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1273" class="LineNr">1273 </span> c3/return -<span id="L1274" class="LineNr">1274 </span> -<span id="L1275" class="LineNr">1275 </span><span class="subxFunction">until-ata-data-available</span>: -<span id="L1276" class="LineNr">1276 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L1277" class="LineNr">1277 </span> 50/push-eax -<span id="L1278" class="LineNr">1278 </span> 52/push-edx -<span id="L1279" class="LineNr">1279 </span> <span class="subxComment">#</span> -<span id="L1280" class="LineNr">1280 </span> ba/copy-to-edx 0x1f7/imm32 -<span id="L1281" class="LineNr">1281 </span> { -<span id="L1282" class="LineNr">1282 </span> ec/read-port-dx-into-al -<span id="L1283" class="LineNr">1283 </span> a8/test-bits-in-al 8/imm8/drq <span class="subxComment"># set zf if bit 3 is not set</span> -<span id="L1284" class="LineNr">1284 </span> 74/jump-if-zf-set-and-bit-3-not-set <span class="Constant">loop</span>/disp8 -<span id="L1285" class="LineNr">1285 </span> } -<span id="L1286" class="LineNr">1286 </span><span class="Constant">$while-ata-busy:end</span>: -<span id="L1287" class="LineNr">1287 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L1288" class="LineNr">1288 </span> 5a/pop-to-edx -<span id="L1289" class="LineNr">1289 </span> 58/pop-to-eax -<span id="L1290" class="LineNr">1290 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L1291" class="LineNr">1291 </span> c3/return -<span id="L1292" class="LineNr">1292 </span> -<span id="L1293" class="LineNr">1293 </span><span class="subxFunction">until-ata-ready-for-data</span>: -<span id="L1294" class="LineNr">1294 </span> (<a href='boot.subx.html#L1275'>until-ata-data-available</a>) -<span id="L1295" class="LineNr">1295 </span> c3/return -<span id="L1296" class="LineNr">1296 </span> -<span id="L1297" class="LineNr">1297 </span><span class="subxComment"># vim:ft=subx</span> +<span id="L231" class="LineNr"> 231 </span> e9/jump <span class="SpecialChar">Entry</span>/disp32 +<span id="L232" class="LineNr"> 232 </span> +<span id="L233" class="LineNr"> 233 </span>== boot-sector-marker 0x7dfe +<span id="L234" class="LineNr"> 234 </span><span class="subxComment"># final 2 bytes of boot sector</span> +<span id="L235" class="LineNr"> 235 </span>55 aa +<span id="L236" class="LineNr"> 236 </span> +<span id="L237" class="LineNr"> 237 </span><span class="subxComment">## sector 2 onwards loaded by load_disk, not automatically on boot</span> +<span id="L238" class="LineNr"> 238 </span> +<span id="L239" class="LineNr"> 239 </span>== data 0x7e00 +<span id="L240" class="LineNr"> 240 </span><span class="subxFunction">idt_descriptor</span>: +<span id="L241" class="LineNr"> 241 </span> ff 03 <span class="subxComment"># final index of idt = size of idt - 1</span> +<span id="L242" class="LineNr"> 242 </span> <a href='boot.subx.html#L246'>idt_start</a>/imm32/start +<span id="L243" class="LineNr"> 243 </span> +<span id="L244" class="Folded"> 244 </span><span class="Folded">+-- 55 lines: # interrupt descriptor table ----------------------------------------------------------------------------------------------------------------------------------------------</span> +<span id="L299" class="LineNr"> 299 </span> +<span id="L300" class="LineNr"> 300 </span>== code +<span id="L301" class="LineNr"> 301 </span> +<span id="L302" class="LineNr"> 302 </span><span class="subxFunction">null-interrupt-handler</span>: +<span id="L303" class="LineNr"> 303 </span> cf/return-from-interrupt +<span id="L304" class="LineNr"> 304 </span> +<span id="L305" class="LineNr"> 305 </span><span class="subxFunction">keyboard-interrupt-handler</span>: +<span id="L306" class="LineNr"> 306 </span> <span class="subxComment"># prologue</span> +<span id="L307" class="LineNr"> 307 </span> fa/disable-interrupts +<span id="L308" class="LineNr"> 308 </span> 60/push-all-registers +<span id="L309" class="LineNr"> 309 </span> <span class="subxComment"># acknowledge interrupt</span> +<span id="L310" class="LineNr"> 310 </span> b0/copy-to-al 0x20/imm8 +<span id="L311" class="LineNr"> 311 </span> e6/write-al-into-port 0x20/imm8 +<span id="L312" class="LineNr"> 312 </span> 31/xor %eax 0/r32/eax +<span id="L313" class="LineNr"> 313 </span> <span class="subxComment"># check output buffer of 8042 keyboard controller (<a href="https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)">https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)</a></span> +<span id="L314" class="LineNr"> 314 </span> e4/read-port-into-al 0x64/imm8 +<span id="L315" class="LineNr"> 315 </span> a8/test-bits-in-al 0x01/imm8 <span class="subxComment"># set zf if bit 0 (least significant) is not set</span> +<span id="L316" class="LineNr"> 316 </span> 74/jump-if-not-set $keyboard-interrupt-handler:epilogue/disp8 +<span id="L317" class="LineNr"> 317 </span> <span class="subxH1Comment"># - if keyboard buffer is full, return</span> +<span id="L318" class="LineNr"> 318 </span> <span class="subxComment"># var dest-addr/ecx: (addr byte) = (keyboard-buffer + *keyboard-buffer:write)</span> +<span id="L319" class="LineNr"> 319 </span> 31/xor %ecx 1/r32/ecx +<span id="L320" class="LineNr"> 320 </span> 8a/byte-> *<span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a> 1/r32/cl +<span id="L321" class="LineNr"> 321 </span> 81 0/subop/add %ecx <span class="SpecialChar">Keyboard-buffer</span>:data/imm32 +<span id="L322" class="LineNr"> 322 </span> <span class="subxComment"># al = *dest-addr</span> +<span id="L323" class="LineNr"> 323 </span> 8a/byte-> *ecx 0/r32/al +<span id="L324" class="LineNr"> 324 </span> <span class="subxComment"># if (al != 0) return</span> +<span id="L325" class="LineNr"> 325 </span> 3c/compare-al-and 0/imm8 +<span id="L326" class="LineNr"> 326 </span> 75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8 +<span id="L327" class="LineNr"> 327 </span> <span class="subxH1Comment"># - read keycode</span> +<span id="L328" class="LineNr"> 328 </span> e4/read-port-into-al 0x60/imm8 +<span id="L329" class="LineNr"> 329 </span> <span class="subxH1Comment"># - key released</span> +<span id="L330" class="LineNr"> 330 </span> <span class="subxComment"># if (al == 0xaa) shift = false # left shift is being lifted</span> +<span id="L331" class="LineNr"> 331 </span> { +<span id="L332" class="LineNr"> 332 </span> 3c/compare-al-and 0xaa/imm8 +<span id="L333" class="LineNr"> 333 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L334" class="LineNr"> 334 </span> <span class="subxComment"># *shift = 0</span> +<span id="L335" class="LineNr"> 335 </span> c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32 +<span id="L336" class="LineNr"> 336 </span> } +<span id="L337" class="LineNr"> 337 </span> <span class="subxComment"># if (al == 0xb6) shift = false # right shift is being lifted</span> +<span id="L338" class="LineNr"> 338 </span> { +<span id="L339" class="LineNr"> 339 </span> 3c/compare-al-and 0xb6/imm8 +<span id="L340" class="LineNr"> 340 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L341" class="LineNr"> 341 </span> <span class="subxComment"># *shift = 0</span> +<span id="L342" class="LineNr"> 342 </span> c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32 +<span id="L343" class="LineNr"> 343 </span> } +<span id="L344" class="LineNr"> 344 </span> <span class="subxComment"># if (al == 0x9d) ctrl = false # ctrl is being lifted</span> +<span id="L345" class="LineNr"> 345 </span> { +<span id="L346" class="LineNr"> 346 </span> 3c/compare-al-and 0x9d/imm8 +<span id="L347" class="LineNr"> 347 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L348" class="LineNr"> 348 </span> <span class="subxComment"># *ctrl = 0</span> +<span id="L349" class="LineNr"> 349 </span> c7 0/subop/copy *Keyboard-ctrl-pressed? 0/imm32 +<span id="L350" class="LineNr"> 350 </span> } +<span id="L351" class="LineNr"> 351 </span> <span class="subxComment"># if (al & 0x80) a key is being lifted; return</span> +<span id="L352" class="LineNr"> 352 </span> 50/push-eax +<span id="L353" class="LineNr"> 353 </span> 24/and-al-with 0x80/imm8 +<span id="L354" class="LineNr"> 354 </span> 3c/compare-al-and 0/imm8 +<span id="L355" class="LineNr"> 355 </span> 58/pop-to-eax +<span id="L356" class="LineNr"> 356 </span> 75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8 +<span id="L357" class="LineNr"> 357 </span> <span class="subxH1Comment"># - key pressed</span> +<span id="L358" class="LineNr"> 358 </span> <span class="subxComment"># if (al == 0x2a) shift = true, return # left shift pressed</span> +<span id="L359" class="LineNr"> 359 </span> { +<span id="L360" class="LineNr"> 360 </span> 3c/compare-al-and 0x2a/imm8 +<span id="L361" class="LineNr"> 361 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L362" class="LineNr"> 362 </span> <span class="subxComment"># *shift = 1</span> +<span id="L363" class="LineNr"> 363 </span> c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32 +<span id="L364" class="LineNr"> 364 </span> <span class="subxComment"># return</span> +<span id="L365" class="LineNr"> 365 </span> eb/jump $keyboard-interrupt-handler:epilogue/disp8 +<span id="L366" class="LineNr"> 366 </span> } +<span id="L367" class="LineNr"> 367 </span> <span class="subxComment"># if (al == 0x36) shift = true, return # right shift pressed</span> +<span id="L368" class="LineNr"> 368 </span> { +<span id="L369" class="LineNr"> 369 </span> 3c/compare-al-and 0x36/imm8 +<span id="L370" class="LineNr"> 370 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L371" class="LineNr"> 371 </span> <span class="subxComment"># *shift = 1</span> +<span id="L372" class="LineNr"> 372 </span> c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32 +<span id="L373" class="LineNr"> 373 </span> <span class="subxComment"># return</span> +<span id="L374" class="LineNr"> 374 </span> eb/jump $keyboard-interrupt-handler:epilogue/disp8 +<span id="L375" class="LineNr"> 375 </span> } +<span id="L376" class="LineNr"> 376 </span> <span class="subxComment"># if (al == 0x1d) ctrl = true, return</span> +<span id="L377" class="LineNr"> 377 </span> { +<span id="L378" class="LineNr"> 378 </span> 3c/compare-al-and 0x1d/imm8 +<span id="L379" class="LineNr"> 379 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L380" class="LineNr"> 380 </span> <span class="subxComment"># *ctrl = 1</span> +<span id="L381" class="LineNr"> 381 </span> c7 0/subop/copy *Keyboard-ctrl-pressed? 1/imm32 +<span id="L382" class="LineNr"> 382 </span> <span class="subxComment"># return</span> +<span id="L383" class="LineNr"> 383 </span> eb/jump $keyboard-interrupt-handler:epilogue/disp8 +<span id="L384" class="LineNr"> 384 </span> } +<span id="L385" class="LineNr"> 385 </span> <span class="subxH1Comment"># - convert key to character</span> +<span id="L386" class="LineNr"> 386 </span> <span class="subxComment"># if (shift) use keyboard shift map</span> +<span id="L387" class="LineNr"> 387 </span> { +<span id="L388" class="LineNr"> 388 </span> 81 7/subop/compare *Keyboard-shift-pressed? 0/imm32 +<span id="L389" class="LineNr"> 389 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L390" class="LineNr"> 390 </span> <span class="subxComment"># sigils don't currently support labels inside *(eax+label)</span> +<span id="L391" class="LineNr"> 391 </span> 05/add-to-eax <span class="SpecialChar"><a href='boot.subx.html#L471'>Keyboard-shift-map</a></span>/imm32 +<span id="L392" class="LineNr"> 392 </span> 8a/byte-> *eax 0/r32/al +<span id="L393" class="LineNr"> 393 </span> eb/jump $keyboard-interrupt-handler:select-map-done/disp8 +<span id="L394" class="LineNr"> 394 </span> } +<span id="L395" class="LineNr"> 395 </span> <span class="subxComment"># if (ctrl) al = *(ctrl map + al)</span> +<span id="L396" class="LineNr"> 396 </span> { +<span id="L397" class="LineNr"> 397 </span> 81 7/subop/compare *Keyboard-ctrl-pressed? 0/imm32 +<span id="L398" class="LineNr"> 398 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L399" class="LineNr"> 399 </span> 05/add-to-eax <span class="SpecialChar"><a href='boot.subx.html#L497'>Keyboard-ctrl-map</a></span>/imm32 +<span id="L400" class="LineNr"> 400 </span> 8a/byte-> *eax 0/r32/al +<span id="L401" class="LineNr"> 401 </span> eb/jump $keyboard-interrupt-handler:select-map-done/disp8 +<span id="L402" class="LineNr"> 402 </span> } +<span id="L403" class="LineNr"> 403 </span> <span class="subxComment"># otherwise al = *(normal map + al)</span> +<span id="L404" class="LineNr"> 404 </span> 05/add-to-eax <span class="SpecialChar"><a href='boot.subx.html#L443'>Keyboard-normal-map</a></span>/imm32 +<span id="L405" class="LineNr"> 405 </span> 8a/byte-> *eax 0/r32/al +<span id="L406" class="LineNr"> 406 </span><span class="Constant">$keyboard-interrupt-handler:select-map-done</span>: +<span id="L407" class="LineNr"> 407 </span> <span class="subxH1Comment"># - if there's no character mapping, return</span> +<span id="L408" class="LineNr"> 408 </span> { +<span id="L409" class="LineNr"> 409 </span> 3c/compare-al-and 0/imm8 +<span id="L410" class="LineNr"> 410 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L411" class="LineNr"> 411 </span> <span class="subxH1Comment"># - store al in keyboard buffer</span> +<span id="L412" class="LineNr"> 412 </span> 88/<- *ecx 0/r32/al +<span id="L413" class="LineNr"> 413 </span> <span class="subxComment"># increment index</span> +<span id="L414" class="LineNr"> 414 </span> fe/increment-byte *<span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a> +<span id="L415" class="LineNr"> 415 </span> <span class="subxComment"># clear top nibble of index (keyboard buffer is circular)</span> +<span id="L416" class="LineNr"> 416 </span> 80 4/subop/and-byte *<span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a> 0x0f/imm8 +<span id="L417" class="LineNr"> 417 </span> } +<span id="L418" class="LineNr"> 418 </span><span class="Constant">$keyboard-interrupt-handler:epilogue</span>: +<span id="L419" class="LineNr"> 419 </span> <span class="subxComment"># epilogue</span> +<span id="L420" class="LineNr"> 420 </span> 61/pop-all-registers +<span id="L421" class="LineNr"> 421 </span> fb/enable-interrupts +<span id="L422" class="LineNr"> 422 </span> cf/return-from-interrupt +<span id="L423" class="LineNr"> 423 </span> +<span id="L424" class="LineNr"> 424 </span>== data +<span id="L425" class="LineNr"> 425 </span>Keyboard-shift-pressed?: <span class="subxComment"># boolean</span> +<span id="L426" class="LineNr"> 426 </span> 0/imm32 +<span id="L427" class="LineNr"> 427 </span> +<span id="L428" class="LineNr"> 428 </span>Keyboard-ctrl-pressed?: <span class="subxComment"># boolean</span> +<span id="L429" class="LineNr"> 429 </span> 0/imm32 +<span id="L430" class="LineNr"> 430 </span> +<span id="L431" class="LineNr"> 431 </span><span class="subxComment"># var keyboard circular buffer</span> +<span id="L432" class="LineNr"> 432 </span><span class="SpecialChar">Keyboard-buffer</span>:<a href='108write.subx.html#L11'>write</a>: <span class="subxComment"># nibble</span> +<span id="L433" class="LineNr"> 433 </span> 0/imm32 +<span id="L434" class="LineNr"> 434 </span><span class="SpecialChar">Keyboard-buffer</span>:read: <span class="subxComment"># nibble</span> +<span id="L435" class="LineNr"> 435 </span> 0/imm32 +<span id="L436" class="LineNr"> 436 </span><span class="SpecialChar">Keyboard-buffer</span>:data: <span class="subxComment"># byte[16]</span> +<span id="L437" class="LineNr"> 437 </span> 00 00 00 00 +<span id="L438" class="LineNr"> 438 </span> 00 00 00 00 +<span id="L439" class="LineNr"> 439 </span> 00 00 00 00 +<span id="L440" class="LineNr"> 440 </span> 00 00 00 00 +<span id="L441" class="LineNr"> 441 </span> +<span id="L442" class="Folded"> 442 </span><span class="Folded">+-- 70 lines: # Keyboard maps for translating keys to ASCII -----------------------------------------------------------------------------------------------------------------------------</span> +<span id="L512" class="LineNr"> 512 </span> +<span id="L513" class="LineNr"> 513 </span><span class="SpecialChar">Video-mode-info</span>: +<span id="L514" class="Folded"> 514 </span><span class="Folded">+-- 53 lines: # video mode info ---------------------------------------------------------------------------------------------------------------------------------------------------------</span> +<span id="L567" class="LineNr"> 567 </span> +<span id="L568" class="LineNr"> 568 </span><span class="SpecialChar">Font</span>: +<span id="L569" class="Folded"> 569 </span><span class="Folded">+--236 lines: # Bitmaps for some ASCII characters (soon Unicode) ------------------------------------------------------------------------------------------------------------------------</span> +<span id="L805" class="LineNr"> 805 </span> +<span id="L806" class="LineNr"> 806 </span>== code +<span id="L807" class="LineNr"> 807 </span> +<span id="L808" class="LineNr"> 808 </span><span class="subxComment">## Controlling IDE (ATA) hard disks</span> +<span id="L809" class="LineNr"> 809 </span><span class="subxComment"># Uses 28-bit PIO mode.</span> +<span id="L810" class="LineNr"> 810 </span><span class="subxComment"># Inspired by <a href="https://colorforth.github.io/ide.html">https://colorforth.github.io/ide.html</a></span> +<span id="L811" class="LineNr"> 811 </span><span class="subxComment">#</span> +<span id="L812" class="LineNr"> 812 </span><span class="subxComment"># Resources:</span> +<span id="L813" class="LineNr"> 813 </span><span class="subxComment"># <a href="https://wiki.osdev.org/ATA_PIO_Mode">https://wiki.osdev.org/ATA_PIO_Mode</a></span> +<span id="L814" class="LineNr"> 814 </span><span class="subxComment"># <a href="https://forum.osdev.org/viewtopic.php?f=1&p=167798">https://forum.osdev.org/viewtopic.php?f=1&p=167798</a></span> +<span id="L815" class="LineNr"> 815 </span><span class="subxComment"># read-sector, according to <a href="https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf">https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf</a></span> +<span id="L816" class="LineNr"> 816 </span> +<span id="L817" class="LineNr"> 817 </span><span class="subxFunction">load-first-sector-from-primary-bus-secondary-drive</span>: <span class="subxComment"># out: (addr stream byte)</span> +<span id="L818" class="LineNr"> 818 </span> <span class="subxS1Comment"># . prologue</span> +<span id="L819" class="LineNr"> 819 </span> 55/push-ebp +<span id="L820" class="LineNr"> 820 </span> 89/<- %ebp 4/r32/esp +<span id="L821" class="LineNr"> 821 </span> <span class="subxS1Comment"># . save registers</span> +<span id="L822" class="LineNr"> 822 </span> 50/push-eax +<span id="L823" class="LineNr"> 823 </span> 51/push-ecx +<span id="L824" class="LineNr"> 824 </span> 52/push-edx +<span id="L825" class="LineNr"> 825 </span> <span class="subxComment"># check for drive</span> +<span id="L826" class="LineNr"> 826 </span> (<a href='boot.subx.html#L951'>secondary-drive-exists?</a>) <span class="subxComment"># => eax</span> +<span id="L827" class="LineNr"> 827 </span> 3d/compare-eax-and 0/imm32/false +<span id="L828" class="LineNr"> 828 </span> 0f 84/jump-if-= $load-first-sector-from-primary-bus-secondary-drive:end/disp32 +<span id="L829" class="LineNr"> 829 </span> <span class="subxComment"># kick off read</span> +<span id="L830" class="LineNr"> 830 </span> (<a href='boot.subx.html#L1011'>ata-drive-select</a> 0xf0) <span class="subxComment"># primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0)</span> +<span id="L831" class="LineNr"> 831 </span> (<a href='boot.subx.html#L1031'>clear-ata-error</a>) +<span id="L832" class="LineNr"> 832 </span> (<a href='boot.subx.html#L1051'>ata-sector-count</a> 1) +<span id="L833" class="LineNr"> 833 </span> (<a href='boot.subx.html#L1071'>ata-lba</a> 0 0 0) <span class="subxComment"># lower 24 bits of LBA, all 0</span> +<span id="L834" class="LineNr"> 834 </span> (<a href='boot.subx.html#L1129'>ata-command</a> 0x20) <span class="subxComment"># read sectors with retries</span> +<span id="L835" class="LineNr"> 835 </span> <span class="subxComment"># poll for results</span> +<span id="L836" class="LineNr"> 836 </span> (<a href='boot.subx.html#L1149'>while-ata-busy</a>) +<span id="L837" class="LineNr"> 837 </span> (<a href='boot.subx.html#L1167'>until-ata-data-available</a>) +<span id="L838" class="LineNr"> 838 </span> <span class="subxComment"># emit results</span> +<span id="L839" class="LineNr"> 839 </span> 31/xor %eax 0/r32/eax +<span id="L840" class="LineNr"> 840 </span> ba/copy-to-edx 0x1f0/imm32 +<span id="L841" class="LineNr"> 841 </span> b9/copy-to-ecx 0x200/imm32 <span class="subxComment"># 512 bytes per sector</span> +<span id="L842" class="LineNr"> 842 </span> { +<span id="L843" class="LineNr"> 843 </span> 81 7/subop/compare %ecx 0/imm32 +<span id="L844" class="LineNr"> 844 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L845" class="LineNr"> 845 </span> 66 ed/read-port-dx-into-ax +<span id="L846" class="LineNr"> 846 </span> <span class="subxComment"># write 2 bytes to stream one at a time</span> +<span id="L847" class="LineNr"> 847 </span> (<a href='115write-byte.subx.html#L12'>append-byte</a> *(ebp+8) %eax) +<span id="L848" class="LineNr"> 848 </span> 49/decrement-ecx +<span id="L849" class="LineNr"> 849 </span> c1/shift 5/subop/right-padding-zeroes %eax 8/imm8 +<span id="L850" class="LineNr"> 850 </span> (<a href='115write-byte.subx.html#L12'>append-byte</a> *(ebp+8) %eax) +<span id="L851" class="LineNr"> 851 </span> 49/decrement-ecx +<span id="L852" class="LineNr"> 852 </span> eb/jump <span class="Constant">loop</span>/disp8 +<span id="L853" class="LineNr"> 853 </span> } +<span id="L854" class="LineNr"> 854 </span><span class="Constant">$load-first-sector-from-primary-bus-secondary-drive:end</span>: +<span id="L855" class="LineNr"> 855 </span> <span class="subxS1Comment"># . restore registers</span> +<span id="L856" class="LineNr"> 856 </span> 5a/pop-to-edx +<span id="L857" class="LineNr"> 857 </span> 59/pop-to-ecx +<span id="L858" class="LineNr"> 858 </span> 58/pop-to-eax +<span id="L859" class="LineNr"> 859 </span> <span class="subxS1Comment"># . epilogue</span> +<span id="L860" class="LineNr"> 860 </span> 89/<- %esp 5/r32/ebp +<span id="L861" class="LineNr"> 861 </span> 5d/pop-to-ebp +<span id="L862" class="LineNr"> 862 </span> c3/return +<span id="L863" class="LineNr"> 863 </span> +<span id="L864" class="LineNr"> 864 </span><span class="subxFunction">store-first-sector-to-primary-bus-secondary-drive</span>: <span class="subxComment"># in: (addr stream byte)</span> +<span id="L865" class="LineNr"> 865 </span> <span class="subxS1Comment"># . prologue</span> +<span id="L866" class="LineNr"> 866 </span> 55/push-ebp +<span id="L867" class="LineNr"> 867 </span> 89/<- %ebp 4/r32/esp +<span id="L868" class="LineNr"> 868 </span> <span class="subxS1Comment"># . save registers</span> +<span id="L869" class="LineNr"> 869 </span> 50/push-eax +<span id="L870" class="LineNr"> 870 </span> 51/push-ecx +<span id="L871" class="LineNr"> 871 </span> 52/push-edx +<span id="L872" class="LineNr"> 872 </span> 53/push-ebx +<span id="L873" class="LineNr"> 873 </span> <span class="subxComment"># check for drive</span> +<span id="L874" class="LineNr"> 874 </span> (<a href='boot.subx.html#L951'>secondary-drive-exists?</a>) <span class="subxComment"># => eax</span> +<span id="L875" class="LineNr"> 875 </span> 3d/compare-eax-and 0/imm32/false +<span id="L876" class="LineNr"> 876 </span> 0f 84/jump-if-= $store-first-sector-to-primary-bus-secondary-drive:end/disp32 +<span id="L877" class="LineNr"> 877 </span> <span class="subxComment"># kick off write</span> +<span id="L878" class="LineNr"> 878 </span> (<a href='boot.subx.html#L1011'>ata-drive-select</a> 0xf0) <span class="subxComment"># primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0)</span> +<span id="L879" class="LineNr"> 879 </span> (<a href='boot.subx.html#L1031'>clear-ata-error</a>) +<span id="L880" class="LineNr"> 880 </span> (<a href='boot.subx.html#L1051'>ata-sector-count</a> 1) +<span id="L881" class="LineNr"> 881 </span> (<a href='boot.subx.html#L1071'>ata-lba</a> 0 0 0) <span class="subxComment"># lower 24 bits of LBA, all 0</span> +<span id="L882" class="LineNr"> 882 </span> (<a href='boot.subx.html#L1129'>ata-command</a> 0x30) <span class="subxComment"># write sectors with retries</span> +<span id="L883" class="LineNr"> 883 </span> <span class="subxComment"># wait</span> +<span id="L884" class="LineNr"> 884 </span> (<a href='boot.subx.html#L1149'>while-ata-busy</a>) +<span id="L885" class="LineNr"> 885 </span> (<a href='boot.subx.html#L1185'>until-ata-ready-for-data</a>) +<span id="L886" class="LineNr"> 886 </span> <span class="subxComment"># send data</span> +<span id="L887" class="LineNr"> 887 </span> ba/copy-to-edx 0x1f0/imm32 +<span id="L888" class="LineNr"> 888 </span> b9/copy-to-ecx 0x200/imm32 <span class="subxComment"># 512 bytes per sector</span> +<span id="L889" class="LineNr"> 889 </span> <span class="subxComment"># var first-byte/ebx: byte</span> +<span id="L890" class="LineNr"> 890 </span> <span class="subxComment"># when it's more than 0xff, we're at an even-numbered byte</span> +<span id="L891" class="LineNr"> 891 </span> bb/copy-to-ebx 0xffff/imm32 +<span id="L892" class="LineNr"> 892 </span><span class="Constant">$store-first-sector-to-primary-bus-secondary-drive:loop</span>: +<span id="L893" class="LineNr"> 893 </span> { +<span id="L894" class="LineNr"> 894 </span> 81 7/subop/compare %ecx 0/imm32 +<span id="L895" class="LineNr"> 895 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L896" class="LineNr"> 896 </span> <span class="subxComment"># this loop is slow, but the ATA spec also requires a small delay</span> +<span id="L897" class="LineNr"> 897 </span> (<a href='309stream.subx.html#L6'>stream-empty?</a> *(ebp+8)) <span class="subxComment"># => eax</span> +<span id="L898" class="LineNr"> 898 </span> 3d/compare-eax-and 0/imm32/false +<span id="L899" class="LineNr"> 899 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L900" class="LineNr"> 900 </span> <span class="subxComment"># read byte from stream</span> +<span id="L901" class="LineNr"> 901 </span> (<a href='112read-byte.subx.html#L13'>read-byte</a> *(ebp+8)) <span class="subxComment"># => eax</span> +<span id="L902" class="LineNr"> 902 </span> <span class="subxComment"># if we're at an odd-numbered byte, save it to first-byte</span> +<span id="L903" class="LineNr"> 903 </span> 81 7/subop/compare %ebx 0xff/imm32 +<span id="L904" class="LineNr"> 904 </span> { +<span id="L905" class="LineNr"> 905 </span> 7e/jump-if-<= <span class="Constant">break</span>/disp8 +<span id="L906" class="LineNr"> 906 </span> 89/<- %ebx 0/r32/eax +<span id="L907" class="LineNr"> 907 </span> eb/jump $store-first-sector-to-primary-bus-secondary-drive:<span class="Constant">loop</span>/disp8 +<span id="L908" class="LineNr"> 908 </span> } +<span id="L909" class="LineNr"> 909 </span> <span class="subxComment"># otherwise OR it with first-byte and write it out</span> +<span id="L910" class="LineNr"> 910 </span> c1/shift 4/subop/left %eax 8/imm8 +<span id="L911" class="LineNr"> 911 </span> 09/or %eax 3/r32/ebx +<span id="L912" class="LineNr"> 912 </span> 66 ef/write-ax-into-port-dx +<span id="L913" class="LineNr"> 913 </span> 49/decrement-ecx +<span id="L914" class="LineNr"> 914 </span> 49/decrement-ecx +<span id="L915" class="LineNr"> 915 </span> <span class="subxComment"># reset first-byte</span> +<span id="L916" class="LineNr"> 916 </span> bb/copy-to-ebx 0xffff/imm32 +<span id="L917" class="LineNr"> 917 </span> eb/jump <span class="Constant">loop</span>/disp8 +<span id="L918" class="LineNr"> 918 </span> } +<span id="L919" class="LineNr"> 919 </span> <span class="subxComment"># write out first-byte if necessary</span> +<span id="L920" class="LineNr"> 920 </span> 81 7/subop/compare %ebx 0xff/imm32 +<span id="L921" class="LineNr"> 921 </span> { +<span id="L922" class="LineNr"> 922 </span> 7f/jump-if-> <span class="Constant">break</span>/disp8 +<span id="L923" class="LineNr"> 923 </span> 89/<- %eax 3/r32/ebx +<span id="L924" class="LineNr"> 924 </span> 66 ef/write-ax-into-port-dx +<span id="L925" class="LineNr"> 925 </span> 49/decrement-ecx +<span id="L926" class="LineNr"> 926 </span> 49/decrement-ecx +<span id="L927" class="LineNr"> 927 </span> } +<span id="L928" class="LineNr"> 928 </span> <span class="subxComment"># pad zeroes</span> +<span id="L929" class="LineNr"> 929 </span> 31/xor %eax 0/r32/eax +<span id="L930" class="LineNr"> 930 </span> { +<span id="L931" class="LineNr"> 931 </span> 81 7/subop/compare %ecx 0/imm32 +<span id="L932" class="LineNr"> 932 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L933" class="LineNr"> 933 </span> 66 ef/write-ax-into-port-dx +<span id="L934" class="LineNr"> 934 </span> 49/decrement-ecx +<span id="L935" class="LineNr"> 935 </span> 49/decrement-ecx +<span id="L936" class="LineNr"> 936 </span> eb/jump <span class="Constant">loop</span>/disp8 +<span id="L937" class="LineNr"> 937 </span> } +<span id="L938" class="LineNr"> 938 </span><span class="Constant">$store-first-sector-to-primary-bus-secondary-drive:end</span>: +<span id="L939" class="LineNr"> 939 </span> <span class="subxS1Comment"># . restore registers</span> +<span id="L940" class="LineNr"> 940 </span> 5b/pop-to-ebx +<span id="L941" class="LineNr"> 941 </span> 5a/pop-to-edx +<span id="L942" class="LineNr"> 942 </span> 59/pop-to-ecx +<span id="L943" class="LineNr"> 943 </span> 58/pop-to-eax +<span id="L944" class="LineNr"> 944 </span> <span class="subxS1Comment"># . epilogue</span> +<span id="L945" class="LineNr"> 945 </span> 89/<- %esp 5/r32/ebp +<span id="L946" class="LineNr"> 946 </span> 5d/pop-to-ebp +<span id="L947" class="LineNr"> 947 </span> c3/return +<span id="L948" class="LineNr"> 948 </span> +<span id="L949" class="Folded"> 949 </span><span class="Folded">+--241 lines: # disk helpers ------------------------------------------------------------------------------------------------------------------------------------------------------------</span> +<span id="L1190" class="LineNr">1190 </span> +<span id="L1191" class="LineNr">1191 </span><span class="subxComment">## Controlling a PS/2 mouse</span> +<span id="L1192" class="LineNr">1192 </span><span class="subxComment"># Uses no IRQs, just polling.</span> +<span id="L1193" class="LineNr">1193 </span><span class="subxComment"># Thanks Dave Long: <a href="https://github.com/jtauber/cleese/blob/master/necco/kernel/bochs/py8042.py">https://github.com/jtauber/cleese/blob/master/necco/kernel/bochs/py8042.py</a></span> +<span id="L1194" class="LineNr">1194 </span><span class="subxComment">#</span> +<span id="L1195" class="LineNr">1195 </span><span class="subxComment"># Resources:</span> +<span id="L1196" class="LineNr">1196 </span><span class="subxComment"># <a href="https://wiki.osdev.org/Mouse_Input">https://wiki.osdev.org/Mouse_Input</a></span> +<span id="L1197" class="LineNr">1197 </span> +<span id="L1198" class="LineNr">1198 </span><span class="subxComment"># results x/eax, y/ecx range from -256 to +255</span> +<span id="L1199" class="LineNr">1199 </span><span class="subxComment"># See <a href="https://wiki.osdev.org/index.php?title=Mouse_Input&oldid=25663#Format_of_First_3_Packet_Bytes">https://wiki.osdev.org/index.php?title=Mouse_Input&oldid=25663#Format_of_First_3_Packet_Bytes</a></span> +<span id="L1200" class="LineNr">1200 </span><span class="subxFunction">read-mouse-event</span>: <span class="subxComment"># -> _/eax: int, _/ecx: int</span> +<span id="L1201" class="LineNr">1201 </span> <span class="subxS1Comment"># . prologue</span> +<span id="L1202" class="LineNr">1202 </span> 55/push-ebp +<span id="L1203" class="LineNr">1203 </span> 89/<- %ebp 4/r32/esp +<span id="L1204" class="LineNr">1204 </span> <span class="subxS1Comment"># . save registers</span> +<span id="L1205" class="LineNr">1205 </span> 52/push-edx +<span id="L1206" class="LineNr">1206 </span> 53/push-ebx +<span id="L1207" class="LineNr">1207 </span> <span class="subxComment"># if no event, return 0, 0</span> +<span id="L1208" class="LineNr">1208 </span> b8/copy-to-eax 0/imm32 +<span id="L1209" class="LineNr">1209 </span> b9/copy-to-ecx 0/imm32 +<span id="L1210" class="LineNr">1210 </span> (<a href='boot.subx.html#L1267'>any-mouse-event?</a>) <span class="subxComment"># => eax</span> +<span id="L1211" class="LineNr">1211 </span> 3d/compare-eax-and 0/imm32/false +<span id="L1212" class="LineNr">1212 </span> 74/jump-if-= $read-mouse-event:end/disp8 +<span id="L1213" class="LineNr">1213 </span> <span class="subxComment"># var f1/edx: byte = inb(0x60)</span> +<span id="L1214" class="LineNr">1214 </span> 31/xor %eax 0/r32/eax +<span id="L1215" class="LineNr">1215 </span> e4/read-port-into-al 0x60/imm8 +<span id="L1216" class="LineNr">1216 </span> 89/<- %edx 0/r32/eax +<span id="L1217" class="LineNr">1217 </span> (<a href='boot.subx.html#L1252'>wait-for-mouse-event</a>) +<span id="L1218" class="LineNr">1218 </span> <span class="subxComment"># var dx/ebx: byte = inb(0x60)</span> +<span id="L1219" class="LineNr">1219 </span> 31/xor %eax 0/r32/eax +<span id="L1220" class="LineNr">1220 </span> e4/read-port-into-al 0x60/imm8 +<span id="L1221" class="LineNr">1221 </span> 89/<- %ebx 0/r32/eax +<span id="L1222" class="LineNr">1222 </span> (<a href='boot.subx.html#L1252'>wait-for-mouse-event</a>) +<span id="L1223" class="LineNr">1223 </span> <span class="subxComment"># var dy/ecx: byte = inb(0x60)</span> +<span id="L1224" class="LineNr">1224 </span> 31/xor %eax 0/r32/eax +<span id="L1225" class="LineNr">1225 </span> e4/read-port-into-al 0x60/imm8 +<span id="L1226" class="LineNr">1226 </span> 89/<- %ecx 0/r32/eax +<span id="L1227" class="LineNr">1227 </span> <span class="subxComment"># eax = dx</span> +<span id="L1228" class="LineNr">1228 </span> 89/<- %eax 3/r32/ebx +<span id="L1229" class="LineNr">1229 </span> <span class="subxComment"># if (f1 & 0x10) dx = -dx</span> +<span id="L1230" class="LineNr">1230 </span> { +<span id="L1231" class="LineNr">1231 </span> f6 0/subop/test-bits %dl 0x10/imm8 +<span id="L1232" class="LineNr">1232 </span> 74/jump-if-zero <span class="Constant">break</span>/disp8 +<span id="L1233" class="LineNr">1233 </span> 0d/or-eax-with 0xffffff00/imm32 +<span id="L1234" class="LineNr">1234 </span> } +<span id="L1235" class="LineNr">1235 </span> <span class="subxComment"># if (f1 & 0x20) dy = -dy</span> +<span id="L1236" class="LineNr">1236 </span> { +<span id="L1237" class="LineNr">1237 </span> f6 0/subop/test-bits %dl 0x20/imm8 +<span id="L1238" class="LineNr">1238 </span> 74/jump-if-zero <span class="Constant">break</span>/disp8 +<span id="L1239" class="LineNr">1239 </span> 81 1/subop/or %ecx 0xffffff00/imm32 +<span id="L1240" class="LineNr">1240 </span> } +<span id="L1241" class="LineNr">1241 </span><span class="Constant">$read-mouse-event:end</span>: +<span id="L1242" class="LineNr">1242 </span> <span class="subxS1Comment"># . restore registers</span> +<span id="L1243" class="LineNr">1243 </span> 5b/pop-to-ebx +<span id="L1244" class="LineNr">1244 </span> 5a/pop-to-edx +<span id="L1245" class="LineNr">1245 </span> <span class="subxS1Comment"># . epilogue</span> +<span id="L1246" class="LineNr">1246 </span> 89/<- %esp 5/r32/ebp +<span id="L1247" class="LineNr">1247 </span> 5d/pop-to-ebp +<span id="L1248" class="LineNr">1248 </span> c3/return +<span id="L1249" class="LineNr">1249 </span> +<span id="L1250" class="Folded">1250 </span><span class="Folded">+--152 lines: # mouse helpers -----------------------------------------------------------------------------------------------------------------------------------------------------------</span> +<span id="L1402" class="LineNr">1402 </span> +<span id="L1403" class="LineNr">1403 </span><span class="subxComment"># vim:ft=subx</span> </pre> </body> </html> |