7438

3 files changed, 600 insertions, 244 deletions

diff --git a/html/baremetal/boot.hex.html b/html/baremetal/boot.hex.html
index 0e2909f3..f21c8efc 100644
--- a/html/baremetal/boot.hex.html
+++ b/html/baremetal/boot.hex.html
@@ -16,7 +16,7 @@ a { color:inherit; }
 * { font-size:12pt; font-size: 1em; }
 .subxComment { color: #005faf; }
 .LineNr { }
-.subxH1Comment { color: #005faf; text-decoration: underline; }
+.subxS1Comment { color: #0000af; }
 -->
 </style>
 
@@ -84,16 +84,16 @@ if ('onhashchange' in window) {
 <span id="L30" class="LineNr"> 30 </span><span class="subxComment"># Programs using this initialization:</span>
 <span id="L31" class="LineNr"> 31 </span><span class="subxComment">#   - can't use any syscalls</span>
 <span id="L32" class="LineNr"> 32 </span><span class="subxComment">#   - can't print text to video memory (past these boot sectors)</span>
-<span id="L33" class="LineNr"> 33 </span><span class="subxComment">#   - must only print raw pixels (256 colors) to video memory (resolution 1280x1024)</span>
-<span id="L34" class="LineNr"> 34 </span><span class="subxComment">#   - must store their entry-point at address 0x8000</span>
+<span id="L33" class="LineNr"> 33 </span><span class="subxComment">#   - must only print raw pixels (256 colors) to video memory (resolution 1024x768)</span>
+<span id="L34" class="LineNr"> 34 </span><span class="subxComment">#   - must store their entry-point at address 0x8800</span>
 <span id="L35" class="LineNr"> 35 </span>
 <span id="L36" class="LineNr"> 36 </span><span class="subxComment">## 16-bit entry point</span>
 <span id="L37" class="LineNr"> 37 </span>
 <span id="L38" class="LineNr"> 38 </span><span class="subxComment"># Upon reset, the IBM PC:</span>
-<span id="L39" class="LineNr"> 39 </span><span class="subxH1Comment"># - loads the first sector (512 bytes)</span>
-<span id="L40" class="LineNr"> 40 </span><span class="subxComment">#   from some bootable image (see the boot sector marker at the end of this file)</span>
-<span id="L41" class="LineNr"> 41 </span><span class="subxComment">#   to the address range [0x7c00, 0x7e00)</span>
-<span id="L42" class="LineNr"> 42 </span><span class="subxH1Comment"># - starts executing code at address 0x7c00</span>
+<span id="L39" class="LineNr"> 39 </span><span class="subxComment">#   - loads the first sector (512 bytes)</span>
+<span id="L40" class="LineNr"> 40 </span><span class="subxComment">#     from some bootable image (see the boot sector marker at the end of this file)</span>
+<span id="L41" class="LineNr"> 41 </span><span class="subxComment">#     to the address range [0x7c00, 0x7e00)</span>
+<span id="L42" class="LineNr"> 42 </span><span class="subxComment">#   - starts executing code at address 0x7c00</span>
 <span id="L43" class="LineNr"> 43 </span>
 <span id="L44" class="LineNr"> 44 </span><span class="subxComment"># offset 00 (address 0x7c00):</span>
 <span id="L45" class="LineNr"> 45 </span>  <span class="subxComment"># disable interrupts for this initialization</span>
@@ -118,13 +118,13 @@ if ('onhashchange' in window) {
 <span id="L64" class="LineNr"> 64 </span>  b5 00  <span class="subxComment"># ch &lt;- 0  # cylinder 0</span>
 <span id="L65" class="LineNr"> 65 </span>  b6 00  <span class="subxComment"># dh &lt;- 0  # track 0</span>
 <span id="L66" class="LineNr"> 66 </span>  b1 02  <span class="subxComment"># cl &lt;- 2  # second sector, 1-based</span>
-<span id="L67" class="LineNr"> 67 </span>  b0 04  <span class="subxComment"># al &lt;- 4  # number of sectors to read</span>
+<span id="L67" class="LineNr"> 67 </span>  b0 10  <span class="subxComment"># al &lt;- 16  # number of sectors to read; all sectors must be in a single track</span>
 <span id="L68" class="LineNr"> 68 </span>  <span class="subxComment"># address to write sectors to = es:bx = 0x7e00, contiguous with boot segment</span>
 <span id="L69" class="LineNr"> 69 </span>  bb 00 00  <span class="subxComment"># bx &lt;- 0</span>
 <span id="L70" class="LineNr"> 70 </span>  8e c3  <span class="subxComment"># es &lt;- bx</span>
-<span id="L71" class="LineNr"> 71 </span>  bb 00 7e  <span class="subxComment"># bx &lt;- 0x7e00</span>
+<span id="L71" class="LineNr"> 71 </span>  bb 00 7e  <span class="subxComment"># bx &lt;- 0x7e00 [label]</span>
 <span id="L72" class="LineNr"> 72 </span>  cd 13  <span class="subxComment"># int 13h, BIOS disk service</span>
-<span id="L73" class="LineNr"> 73 </span>  0f 82 76 00  <span class="subxComment"># jump-if-carry disk-error</span>
+<span id="L73" class="LineNr"> 73 </span>  0f 82 8a 00  <span class="subxComment"># jump-if-carry disk-error [label]</span>
 <span id="L74" class="LineNr"> 74 </span>
 <span id="L75" class="LineNr"> 75 </span><span class="subxComment"># 26:</span>
 <span id="L76" class="LineNr"> 76 </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>
@@ -150,246 +150,488 @@ if ('onhashchange' in window) {
 <span id="L96" class="LineNr"> 96 </span>  <span class="subxComment"># adjust video mode</span>
 <span id="L97" class="LineNr"> 97 </span>  b4 4f  <span class="subxComment"># ah &lt;- 4f (VBE)</span>
 <span id="L98" class="LineNr"> 98 </span>  b0 02  <span class="subxComment"># al &lt;- 02 (set video mode)</span>
-<span id="L99" class="LineNr"> 99 </span>  bb 07 01  <span class="subxComment"># bx &lt;- 0x0107 (graphics 1280x1024x256)</span>
-<span id="L100" class="LineNr">100 </span>            <span class="subxComment"># fallback: 0x0101 (640x480x256)</span>
-<span id="L101" class="LineNr">101 </span>            <span class="subxComment"># for other choices see <a href="http://www.ctyme.com/intr/rb-0069.htm">http://www.ctyme.com/intr/rb-0069.htm</a></span>
+<span id="L99" class="LineNr"> 99 </span>  bb 05 41  <span class="subxComment"># bx &lt;- 0x0105 (graphics 1024x768x256</span>
+<span id="L100" class="LineNr">100 </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="L101" class="LineNr">101 </span>            <span class="subxComment"># fallback mode: 0x0101 (640x480x256)</span>
 <span id="L102" class="LineNr">102 </span>  cd 10  <span class="subxComment"># int 10h, Vesa BIOS extensions</span>
 <span id="L103" class="LineNr">103 </span>
 <span id="L104" class="LineNr">104 </span><span class="subxComment"># 43:</span>
-<span id="L105" class="LineNr">105 </span>  <span class="subxComment"># switch to 32-bit mode</span>
-<span id="L106" class="LineNr">106 </span>  0f 01 16  <span class="subxComment"># lgdt 00/mod/indirect 010/subop 110/rm/use-disp16</span>
-<span id="L107" class="LineNr">107 </span>    80 7c  <span class="subxComment"># *gdt_descriptor</span>
-<span id="L108" class="LineNr">108 </span>  0f 20 c0  <span class="subxComment"># eax &lt;- cr0</span>
-<span id="L109" class="LineNr">109 </span>  66 83 c8 01  <span class="subxComment"># eax &lt;- or 0x1</span>
-<span id="L110" class="LineNr">110 </span>  0f 22 c0  <span class="subxComment"># cr0 &lt;- eax</span>
-<span id="L111" class="LineNr">111 </span>  ea c0 7c 08 00  <span class="subxComment"># far jump to initialize_32bit_mode after setting cs to the record at offset 8 in the gdt (gdt_code)</span>
+<span id="L105" class="LineNr">105 </span>  <span class="subxComment"># load information for the (hopefully) current video mode</span>
+<span id="L106" class="LineNr">106 </span>  <span class="subxComment"># mostly just for the address to the linear frame buffer</span>
+<span id="L107" class="LineNr">107 </span>  b4 4f  <span class="subxComment"># ah &lt;- 4f (VBE)</span>
+<span id="L108" class="LineNr">108 </span>  b0 01  <span class="subxComment"># al &lt;- 01 (get video mode)</span>
+<span id="L109" class="LineNr">109 </span>  b9 07 01  <span class="subxComment"># cx &lt;- 0x0107 (mode we requested)</span>
+<span id="L110" class="LineNr">110 </span>  bf 00 7f  <span class="subxComment"># di &lt;- 0x7f00 (video mode info) [label]</span>
+<span id="L111" class="LineNr">111 </span>  cd 10
 <span id="L112" class="LineNr">112 </span>
-<span id="L113" class="LineNr">113 </span><span class="subxComment"># padding</span>
-<span id="L114" class="LineNr">114 </span><span class="subxComment"># 57:</span>
-<span id="L115" class="LineNr">115 </span>                     00 00 00 00 00 00 00 00 00
-<span id="L116" class="LineNr">116 </span>
-<span id="L117" class="LineNr">117 </span><span class="subxComment">## GDT: 3 records of 8 bytes each</span>
-<span id="L118" class="LineNr">118 </span>
-<span id="L119" class="LineNr">119 </span><span class="subxComment"># 60:</span>
-<span id="L120" class="LineNr">120 </span><span class="subxComment"># gdt_start:</span>
-<span id="L121" class="LineNr">121 </span><span class="subxComment"># gdt_null:  mandatory null descriptor</span>
-<span id="L122" class="LineNr">122 </span>  00 00 00 00 00 00 00 00
-<span id="L123" class="LineNr">123 </span><span class="subxComment"># gdt_code:  (offset 8 from gdt_start)</span>
-<span id="L124" class="LineNr">124 </span>  ff ff  <span class="subxComment"># limit[0:16]</span>
-<span id="L125" class="LineNr">125 </span>  00 00 00  <span class="subxComment"># base[0:24]</span>
-<span id="L126" class="LineNr">126 </span>  9a  <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span>
-<span id="L127" class="LineNr">127 </span>      <span class="subxComment"># 1/code 0/conforming 1/readable 0/accessed = 1010b</span>
-<span id="L128" class="LineNr">128 </span>  cf  <span class="subxComment"># 1/granularity 1/32-bit 0/64-bit-segment 0/AVL = 1100b</span>
-<span id="L129" class="LineNr">129 </span>      <span class="subxComment"># limit[16:20] = 1111b</span>
-<span id="L130" class="LineNr">130 </span>  00  <span class="subxComment"># base[24:32]</span>
-<span id="L131" class="LineNr">131 </span><span class="subxComment"># gdt_data:  (offset 16 from gdt_start)</span>
-<span id="L132" class="LineNr">132 </span>  ff ff  <span class="subxComment"># limit[0:16]</span>
-<span id="L133" class="LineNr">133 </span>  00 00 00  <span class="subxComment"># base[0:24]</span>
-<span id="L134" class="LineNr">134 </span>  92  <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span>
-<span id="L135" class="LineNr">135 </span>      <span class="subxComment"># 0/data 0/conforming 1/readable 0/accessed = 0010b</span>
-<span id="L136" class="LineNr">136 </span>  cf  <span class="subxComment"># same as gdt_code</span>
-<span id="L137" class="LineNr">137 </span>  00  <span class="subxComment"># base[24:32]</span>
-<span id="L138" class="LineNr">138 </span><span class="subxComment"># gdt_end:</span>
-<span id="L139" class="LineNr">139 </span>
-<span id="L140" class="LineNr">140 </span><span class="subxComment"># padding</span>
-<span id="L141" class="LineNr">141 </span><span class="subxComment"># 78:</span>
-<span id="L142" class="LineNr">142 </span>                        00 00 00 00 00 00 00 00
-<span id="L143" class="LineNr">143 </span>
-<span id="L144" class="LineNr">144 </span><span class="subxComment"># 80:</span>
-<span id="L145" class="LineNr">145 </span><span class="subxComment"># gdt_descriptor:</span>
-<span id="L146" class="LineNr">146 </span>  17 00  <span class="subxComment"># final index of gdt = gdt_end - gdt_start - 1</span>
-<span id="L147" class="LineNr">147 </span>  60 7c 00 00  <span class="subxComment"># start = gdt_start</span>
-<span id="L148" class="LineNr">148 </span>
-<span id="L149" class="LineNr">149 </span><span class="subxComment"># padding</span>
-<span id="L150" class="LineNr">150 </span><span class="subxComment"># 85:</span>
-<span id="L151" class="LineNr">151 </span>                  00 00 00 00 00 00 00 00 00 00
-<span id="L152" class="LineNr">152 </span>
-<span id="L153" class="LineNr">153 </span><span class="subxComment"># 90:</span>
-<span id="L154" class="LineNr">154 </span><span class="subxComment"># disk_error:</span>
-<span id="L155" class="LineNr">155 </span>  <span class="subxComment"># print 'D' to top-left of screen to indicate disk error</span>
-<span id="L156" class="LineNr">156 </span>  <span class="subxComment"># *0xb8000 &lt;- 0x0f44</span>
-<span id="L157" class="LineNr">157 </span>  <span class="subxComment"># bx &lt;- 0xb800</span>
-<span id="L158" class="LineNr">158 </span>  bb 00 b8
-<span id="L159" class="LineNr">159 </span>  <span class="subxComment"># ds &lt;- bx</span>
-<span id="L160" class="LineNr">160 </span>  8e db  <span class="subxComment"># 11b/mod 011b/reg/ds 011b/rm/bx</span>
-<span id="L161" class="LineNr">161 </span>  <span class="subxComment"># al &lt;- 'D'</span>
-<span id="L162" class="LineNr">162 </span>  b0 44
-<span id="L163" class="LineNr">163 </span>  <span class="subxComment"># ah &lt;- 0x0f  # white on black</span>
-<span id="L164" class="LineNr">164 </span>  b4 0f
-<span id="L165" class="LineNr">165 </span>  <span class="subxComment"># bx &lt;- 0</span>
-<span id="L166" class="LineNr">166 </span>  bb 00 00
-<span id="L167" class="LineNr">167 </span>  <span class="subxComment"># *ds:bx &lt;- ax</span>
-<span id="L168" class="LineNr">168 </span>  89 07  <span class="subxComment"># 00b/mod/indirect 000b/reg/ax 111b/rm/bx</span>
-<span id="L169" class="LineNr">169 </span>
-<span id="L170" class="LineNr">170 </span>e9 fb ff  <span class="subxComment"># loop forever</span>
-<span id="L171" class="LineNr">171 </span>
-<span id="L172" class="LineNr">172 </span><span class="subxComment"># padding</span>
-<span id="L173" class="LineNr">173 </span><span class="subxComment"># a1:</span>
-<span id="L174" class="LineNr">174 </span>   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L175" class="LineNr">175 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L176" class="LineNr">176 </span>
-<span id="L177" class="LineNr">177 </span><span class="subxComment">## 32-bit code from this point (still some instructions not in SubX)</span>
-<span id="L178" class="LineNr">178 </span>
-<span id="L179" class="LineNr">179 </span><span class="subxComment"># c0:</span>
-<span id="L180" class="LineNr">180 </span><span class="subxComment"># initialize_32bit_mode:</span>
-<span id="L181" class="LineNr">181 </span>  66 b8 10 00  <span class="subxComment"># ax &lt;- offset 16 from gdt_start</span>
-<span id="L182" class="LineNr">182 </span>  8e d8  <span class="subxComment"># ds &lt;- ax</span>
-<span id="L183" class="LineNr">183 </span>  8e d0  <span class="subxComment"># ss &lt;- ax</span>
-<span id="L184" class="LineNr">184 </span>  8e c0  <span class="subxComment"># es &lt;- ax</span>
-<span id="L185" class="LineNr">185 </span>  8e e0  <span class="subxComment"># fs &lt;- ax</span>
-<span id="L186" class="LineNr">186 </span>  8e e8  <span class="subxComment"># gs &lt;- ax</span>
-<span id="L187" class="LineNr">187 </span>
-<span id="L188" class="LineNr">188 </span>  <span class="subxComment"># load interrupt handlers</span>
-<span id="L189" class="LineNr">189 </span>  0f 01 1d  <span class="subxComment"># lidt 00/mod/indirect 011/subop 101/rm32/use-disp32</span>
-<span id="L190" class="LineNr">190 </span>    00 7f 00 00  <span class="subxComment"># *idt_descriptor</span>
-<span id="L191" class="LineNr">191 </span>
-<span id="L192" class="LineNr">192 </span>  <span class="subxComment"># enable keyboard IRQ</span>
-<span id="L193" class="LineNr">193 </span>  b0 fd  <span class="subxComment"># al &lt;- 0xfd  # enable just IRQ1</span>
-<span id="L194" class="LineNr">194 </span>  e6 21  <span class="subxComment"># port 0x21 &lt;- al</span>
-<span id="L195" class="LineNr">195 </span>
-<span id="L196" class="LineNr">196 </span>  <span class="subxComment"># initialization is done; enable interrupts</span>
-<span id="L197" class="LineNr">197 </span>  fb
-<span id="L198" class="LineNr">198 </span>  e9 21 03 00 00  <span class="subxComment"># jump to 0x8000</span>
-<span id="L199" class="LineNr">199 </span>
-<span id="L200" class="LineNr">200 </span><span class="subxComment"># padding</span>
-<span id="L201" class="LineNr">201 </span><span class="subxComment"># df:</span>
-<span id="L202" class="LineNr">202 </span>                                             00
-<span id="L203" class="LineNr">203 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L204" class="LineNr">204 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L113" class="LineNr">113 </span><span class="subxComment"># 4f:</span>
+<span id="L114" class="LineNr">114 </span>  <span class="subxComment"># switch to 32-bit mode</span>
+<span id="L115" class="LineNr">115 </span>  0f 01 16  <span class="subxComment"># lgdt 00/mod/indirect 010/subop 110/rm/use-disp16</span>
+<span id="L116" class="LineNr">116 </span>    a0 7c  <span class="subxComment"># *gdt_descriptor [label]</span>
+<span id="L117" class="LineNr">117 </span>  0f 20 c0  <span class="subxComment"># eax &lt;- cr0</span>
+<span id="L118" class="LineNr">118 </span>  66 83 c8 01  <span class="subxComment"># eax &lt;- or 0x1</span>
+<span id="L119" class="LineNr">119 </span>  0f 22 c0  <span class="subxComment"># cr0 &lt;- eax</span>
+<span id="L120" class="LineNr">120 </span>  ea e0 7c 08 00  <span class="subxComment"># far jump to initialize_32bit_mode after setting cs to the record at offset 8 in the gdt (gdt_code) [label]</span>
+<span id="L121" class="LineNr">121 </span>
+<span id="L122" class="LineNr">122 </span><span class="subxComment"># padding</span>
+<span id="L123" class="LineNr">123 </span><span class="subxComment"># 63:</span>
+<span id="L124" class="LineNr">124 </span>         00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L125" class="LineNr">125 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L126" class="LineNr">126 </span>
+<span id="L127" class="LineNr">127 </span><span class="subxComment">## GDT: 3 records of 8 bytes each</span>
+<span id="L128" class="LineNr">128 </span>
+<span id="L129" class="LineNr">129 </span><span class="subxComment"># 80:</span>
+<span id="L130" class="LineNr">130 </span><span class="subxComment"># gdt_start:</span>
+<span id="L131" class="LineNr">131 </span><span class="subxComment"># gdt_null:  mandatory null descriptor</span>
+<span id="L132" class="LineNr">132 </span>  00 00 00 00 00 00 00 00
+<span id="L133" class="LineNr">133 </span><span class="subxComment"># gdt_code:  (offset 8 from gdt_start)</span>
+<span id="L134" class="LineNr">134 </span>  ff ff  <span class="subxComment"># limit[0:16]</span>
+<span id="L135" class="LineNr">135 </span>  00 00 00  <span class="subxComment"># base[0:24]</span>
+<span id="L136" class="LineNr">136 </span>  9a  <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span>
+<span id="L137" class="LineNr">137 </span>      <span class="subxComment"># 1/code 0/conforming 1/readable 0/accessed = 1010b</span>
+<span id="L138" class="LineNr">138 </span>  cf  <span class="subxComment"># 1/granularity 1/32-bit 0/64-bit-segment 0/AVL = 1100b</span>
+<span id="L139" class="LineNr">139 </span>      <span class="subxComment"># limit[16:20] = 1111b</span>
+<span id="L140" class="LineNr">140 </span>  00  <span class="subxComment"># base[24:32]</span>
+<span id="L141" class="LineNr">141 </span><span class="subxComment"># gdt_data:  (offset 16 from gdt_start)</span>
+<span id="L142" class="LineNr">142 </span>  ff ff  <span class="subxComment"># limit[0:16]</span>
+<span id="L143" class="LineNr">143 </span>  00 00 00  <span class="subxComment"># base[0:24]</span>
+<span id="L144" class="LineNr">144 </span>  92  <span class="subxComment"># 1/present 00/privilege 1/descriptor type = 1001b</span>
+<span id="L145" class="LineNr">145 </span>      <span class="subxComment"># 0/data 0/conforming 1/readable 0/accessed = 0010b</span>
+<span id="L146" class="LineNr">146 </span>  cf  <span class="subxComment"># same as gdt_code</span>
+<span id="L147" class="LineNr">147 </span>  00  <span class="subxComment"># base[24:32]</span>
+<span id="L148" class="LineNr">148 </span><span class="subxComment"># gdt_end:</span>
+<span id="L149" class="LineNr">149 </span>
+<span id="L150" class="LineNr">150 </span><span class="subxComment"># padding</span>
+<span id="L151" class="LineNr">151 </span><span class="subxComment"># 98:</span>
+<span id="L152" class="LineNr">152 </span>                        00 00 00 00 00 00 00 00
+<span id="L153" class="LineNr">153 </span>
+<span id="L154" class="LineNr">154 </span><span class="subxComment"># a0:</span>
+<span id="L155" class="LineNr">155 </span><span class="subxComment"># gdt_descriptor:</span>
+<span id="L156" class="LineNr">156 </span>  17 00  <span class="subxComment"># final index of gdt = gdt_end - gdt_start - 1</span>
+<span id="L157" class="LineNr">157 </span>  80 7c 00 00  <span class="subxComment"># start = gdt_start [label]</span>
+<span id="L158" class="LineNr">158 </span>
+<span id="L159" class="LineNr">159 </span><span class="subxComment"># padding</span>
+<span id="L160" class="LineNr">160 </span><span class="subxComment"># a5:</span>
+<span id="L161" class="LineNr">161 </span>                  00 00 00 00 00 00 00 00 00 00
+<span id="L162" class="LineNr">162 </span>
+<span id="L163" class="LineNr">163 </span><span class="subxComment"># b0:</span>
+<span id="L164" class="LineNr">164 </span><span class="subxComment"># disk_error:</span>
+<span id="L165" class="LineNr">165 </span>  <span class="subxComment"># print 'D' to top-left of screen to indicate disk error</span>
+<span id="L166" class="LineNr">166 </span>  <span class="subxComment"># *0xb8000 &lt;- 0x0f44</span>
+<span id="L167" class="LineNr">167 </span>  <span class="subxComment"># bx &lt;- 0xb800</span>
+<span id="L168" class="LineNr">168 </span>  bb 00 b8
+<span id="L169" class="LineNr">169 </span>  <span class="subxComment"># ds &lt;- bx</span>
+<span id="L170" class="LineNr">170 </span>  8e db  <span class="subxComment"># 11b/mod 011b/reg/ds 011b/rm/bx</span>
+<span id="L171" class="LineNr">171 </span>  <span class="subxComment"># al &lt;- 'D'</span>
+<span id="L172" class="LineNr">172 </span>  b0 44
+<span id="L173" class="LineNr">173 </span>  <span class="subxComment"># ah &lt;- 0x0f  # white on black</span>
+<span id="L174" class="LineNr">174 </span>  b4 0f
+<span id="L175" class="LineNr">175 </span>  <span class="subxComment"># bx &lt;- 0</span>
+<span id="L176" class="LineNr">176 </span>  bb 00 00
+<span id="L177" class="LineNr">177 </span>  <span class="subxComment"># *ds:bx &lt;- ax</span>
+<span id="L178" class="LineNr">178 </span>  89 07  <span class="subxComment"># 00b/mod/indirect 000b/reg/ax 111b/rm/bx</span>
+<span id="L179" class="LineNr">179 </span>
+<span id="L180" class="LineNr">180 </span>e9 fb ff  <span class="subxComment"># loop forever</span>
+<span id="L181" class="LineNr">181 </span>
+<span id="L182" class="LineNr">182 </span><span class="subxComment"># padding</span>
+<span id="L183" class="LineNr">183 </span><span class="subxComment"># c1:</span>
+<span id="L184" class="LineNr">184 </span>   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L185" class="LineNr">185 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L186" class="LineNr">186 </span>
+<span id="L187" class="LineNr">187 </span><span class="subxComment">## 32-bit code from this point (still some instructions not in SubX)</span>
+<span id="L188" class="LineNr">188 </span>
+<span id="L189" class="LineNr">189 </span><span class="subxComment"># e0:</span>
+<span id="L190" class="LineNr">190 </span><span class="subxComment"># initialize_32bit_mode:</span>
+<span id="L191" class="LineNr">191 </span>  66 b8 10 00  <span class="subxComment"># ax &lt;- offset 16 from gdt_start</span>
+<span id="L192" class="LineNr">192 </span>  8e d8  <span class="subxComment"># ds &lt;- ax</span>
+<span id="L193" class="LineNr">193 </span>  8e d0  <span class="subxComment"># ss &lt;- ax</span>
+<span id="L194" class="LineNr">194 </span>  8e c0  <span class="subxComment"># es &lt;- ax</span>
+<span id="L195" class="LineNr">195 </span>  8e e0  <span class="subxComment"># fs &lt;- ax</span>
+<span id="L196" class="LineNr">196 </span>  8e e8  <span class="subxComment"># gs &lt;- ax</span>
+<span id="L197" class="LineNr">197 </span>
+<span id="L198" class="LineNr">198 </span>  <span class="subxComment"># load interrupt handlers</span>
+<span id="L199" class="LineNr">199 </span>  0f 01 1d  <span class="subxComment"># lidt 00/mod/indirect 011/subop 101/rm32/use-disp32</span>
+<span id="L200" class="LineNr">200 </span>    f8 7d 00 00  <span class="subxComment"># *idt_descriptor [label]</span>
+<span id="L201" class="LineNr">201 </span>
+<span id="L202" class="LineNr">202 </span>  <span class="subxComment"># enable keyboard IRQ</span>
+<span id="L203" class="LineNr">203 </span>  b0 fd  <span class="subxComment"># al &lt;- 0xfd  # enable just IRQ1</span>
+<span id="L204" class="LineNr">204 </span>  e6 21  <span class="subxComment"># port 0x21 &lt;- al</span>
 <span id="L205" class="LineNr">205 </span>
-<span id="L206" class="LineNr">206 </span><span class="subxComment"># 100:</span>
-<span id="L207" class="LineNr">207 </span><span class="subxComment"># null interrupt handler:</span>
-<span id="L208" class="LineNr">208 </span>  cf  <span class="subxComment"># iret</span>
+<span id="L206" class="LineNr">206 </span>  <span class="subxComment"># initialization is done; enable interrupts</span>
+<span id="L207" class="LineNr">207 </span>  fb
+<span id="L208" class="LineNr">208 </span>  e9 01 0b 00 00  <span class="subxComment"># jump to 0x8800 [label]</span>
 <span id="L209" class="LineNr">209 </span>
 <span id="L210" class="LineNr">210 </span><span class="subxComment"># padding</span>
-<span id="L211" class="LineNr">211 </span><span class="subxComment"># 101:</span>
-<span id="L212" class="LineNr">212 </span>   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L211" class="LineNr">211 </span><span class="subxComment"># ff:</span>
+<span id="L212" class="LineNr">212 </span>                                             00
 <span id="L213" class="LineNr">213 </span>
-<span id="L214" class="LineNr">214 </span><span class="subxComment"># 110:</span>
-<span id="L215" class="LineNr">215 </span><span class="subxComment"># keyboard interrupt handler:</span>
-<span id="L216" class="LineNr">216 </span>  <span class="subxComment"># prologue</span>
-<span id="L217" class="LineNr">217 </span>  fa  <span class="subxComment"># disable interrupts</span>
-<span id="L218" class="LineNr">218 </span>  60  <span class="subxComment"># push all registers to stack</span>
-<span id="L219" class="LineNr">219 </span>  <span class="subxComment"># acknowledge interrupt</span>
-<span id="L220" class="LineNr">220 </span>  b0 20  <span class="subxComment"># al &lt;- 0x20</span>
-<span id="L221" class="LineNr">221 </span>  e6 20  <span class="subxComment"># port 0x20 &lt;- al</span>
-<span id="L222" class="LineNr">222 </span>  <span class="subxComment"># TODO: perhaps we should check keyboard status</span>
-<span id="L223" class="LineNr">223 </span>  <span class="subxComment"># read keycode into eax</span>
-<span id="L224" class="LineNr">224 </span>  31 c0  <span class="subxComment"># eax &lt;- xor eax;  11/direct 000/r32/eax 000/rm32/eax</span>
-<span id="L225" class="LineNr">225 </span>  e4 60  <span class="subxComment"># al &lt;- port 0x60</span>
-<span id="L226" class="LineNr">226 </span>  <span class="subxComment"># map key '1' to ascii; if eax == 2, eax = 0x31</span>
-<span id="L227" class="LineNr">227 </span>  3d 02 00 00 00  <span class="subxComment"># compare eax with 0x02</span>
-<span id="L228" class="LineNr">228 </span>  75 0b  <span class="subxComment"># if not equal, goto epilogue</span>
-<span id="L229" class="LineNr">229 </span>  b8 31 0f 00 00  <span class="subxComment"># eax &lt;- 0x0f31</span>
-<span id="L230" class="LineNr">230 </span>  <span class="subxComment"># print eax to top-left of screen (*0xb8000)</span>
-<span id="L231" class="LineNr">231 </span>  89  <span class="subxComment"># copy r32 to rm32</span>
-<span id="L232" class="LineNr">232 </span>    05  <span class="subxComment"># 00/mod/indirect 000/r32/eax 101/rm32/use-disp32</span>
-<span id="L233" class="LineNr">233 </span>    <span class="subxComment"># disp32</span>
-<span id="L234" class="LineNr">234 </span>    00 80 0b 00
-<span id="L235" class="LineNr">235 </span>  <span class="subxComment"># epilogue</span>
-<span id="L236" class="LineNr">236 </span>  61  <span class="subxComment"># pop all registers</span>
-<span id="L237" class="LineNr">237 </span>  fb  <span class="subxComment"># enable interrupts</span>
-<span id="L238" class="LineNr">238 </span>  cf  <span class="subxComment"># iret</span>
-<span id="L239" class="LineNr">239 </span>
-<span id="L240" class="LineNr">240 </span><span class="subxComment"># padding</span>
-<span id="L241" class="LineNr">241 </span><span class="subxComment"># 12f</span>
-<span id="L242" class="LineNr">242 </span>                                             00
-<span id="L243" class="LineNr">243 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L244" class="LineNr">244 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L245" class="LineNr">245 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L246" class="LineNr">246 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L247" class="LineNr">247 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L248" class="LineNr">248 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L249" class="LineNr">249 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L250" class="LineNr">250 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L251" class="LineNr">251 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L252" class="LineNr">252 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L253" class="LineNr">253 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L254" class="LineNr">254 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L255" class="LineNr">255 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L256" class="LineNr">256 </span>
-<span id="L257" class="LineNr">257 </span><span class="subxComment"># final 2 bytes of boot sector</span>
-<span id="L258" class="LineNr">258 </span>55 aa
-<span id="L259" class="LineNr">259 </span>
-<span id="L260" class="LineNr">260 </span><span class="subxComment">## sector 2</span>
-<span id="L261" class="LineNr">261 </span><span class="subxComment"># loaded by load_disk, not automatically on boot</span>
-<span id="L262" class="LineNr">262 </span>
-<span id="L263" class="LineNr">263 </span><span class="subxComment"># offset 200 (address 0x7e00): interrupt descriptor table</span>
-<span id="L264" class="LineNr">264 </span><span class="subxComment"># 32 entries * 8 bytes each = 256 bytes (0x100)</span>
-<span id="L265" class="LineNr">265 </span><span class="subxComment"># idt_start:</span>
-<span id="L266" class="LineNr">266 </span>
-<span id="L267" class="LineNr">267 </span>00 00 00 00 00 00 00 00
-<span id="L268" class="LineNr">268 </span>00 00 00 00 00 00 00 00
-<span id="L269" class="LineNr">269 </span>00 00 00 00 00 00 00 00
-<span id="L270" class="LineNr">270 </span>00 00 00 00 00 00 00 00
-<span id="L271" class="LineNr">271 </span>00 00 00 00 00 00 00 00
-<span id="L272" class="LineNr">272 </span>00 00 00 00 00 00 00 00
-<span id="L273" class="LineNr">273 </span>00 00 00 00 00 00 00 00
-<span id="L274" class="LineNr">274 </span>00 00 00 00 00 00 00 00
-<span id="L275" class="LineNr">275 </span>
-<span id="L276" class="LineNr">276 </span><span class="subxComment"># entry 8: clock</span>
-<span id="L277" class="LineNr">277 </span>  00 7d  <span class="subxComment"># target[0:16] = null interrupt handler</span>
-<span id="L278" class="LineNr">278 </span>  08 00  <span class="subxComment"># segment selector (gdt_code)</span>
-<span id="L279" class="LineNr">279 </span>  00  <span class="subxComment"># unused</span>
-<span id="L280" class="LineNr">280 </span>  8e  <span class="subxComment"># 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate</span>
-<span id="L281" class="LineNr">281 </span>  00 00  <span class="subxComment"># target[16:32]</span>
-<span id="L282" class="LineNr">282 </span>
-<span id="L283" class="LineNr">283 </span><span class="subxComment"># entry 9: keyboard</span>
-<span id="L284" class="LineNr">284 </span>  10 7d  <span class="subxComment"># target[0:16] = keyboard interrupt handler</span>
-<span id="L285" class="LineNr">285 </span>  08 00  <span class="subxComment"># segment selector (gdt_code)</span>
-<span id="L286" class="LineNr">286 </span>  00  <span class="subxComment"># unused</span>
-<span id="L287" class="LineNr">287 </span>  8e  <span class="subxComment"># 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate</span>
-<span id="L288" class="LineNr">288 </span>  00 00  <span class="subxComment"># target[16:32]</span>
-<span id="L289" class="LineNr">289 </span>
-<span id="L290" class="LineNr">290 </span>00 00 00 00 00 00 00 00
-<span id="L291" class="LineNr">291 </span>00 00 00 00 00 00 00 00
-<span id="L292" class="LineNr">292 </span>00 00 00 00 00 00 00 00
-<span id="L293" class="LineNr">293 </span>00 00 00 00 00 00 00 00
-<span id="L294" class="LineNr">294 </span>00 00 00 00 00 00 00 00
-<span id="L295" class="LineNr">295 </span>00 00 00 00 00 00 00 00
-<span id="L296" class="LineNr">296 </span>00 00 00 00 00 00 00 00
-<span id="L297" class="LineNr">297 </span>00 00 00 00 00 00 00 00
-<span id="L298" class="LineNr">298 </span>00 00 00 00 00 00 00 00
-<span id="L299" class="LineNr">299 </span>00 00 00 00 00 00 00 00
-<span id="L300" class="LineNr">300 </span>00 00 00 00 00 00 00 00
-<span id="L301" class="LineNr">301 </span>00 00 00 00 00 00 00 00
+<span id="L214" class="LineNr">214 </span><span class="subxComment"># 100:</span>
+<span id="L215" class="LineNr">215 </span><span class="subxComment"># null interrupt handler:</span>
+<span id="L216" class="LineNr">216 </span>  cf  <span class="subxComment"># iret</span>
+<span id="L217" class="LineNr">217 </span>
+<span id="L218" class="LineNr">218 </span><span class="subxComment"># padding</span>
+<span id="L219" class="LineNr">219 </span><span class="subxComment"># 101:</span>
+<span id="L220" class="LineNr">220 </span>   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L221" class="LineNr">221 </span>
+<span id="L222" class="LineNr">222 </span><span class="subxComment"># 110:</span>
+<span id="L223" class="LineNr">223 </span><span class="subxComment"># keyboard interrupt handler:</span>
+<span id="L224" class="LineNr">224 </span>  <span class="subxComment"># prologue</span>
+<span id="L225" class="LineNr">225 </span>  fa  <span class="subxComment"># disable interrupts</span>
+<span id="L226" class="LineNr">226 </span>  60  <span class="subxComment"># push all registers to stack</span>
+<span id="L227" class="LineNr">227 </span>  <span class="subxComment"># acknowledge interrupt</span>
+<span id="L228" class="LineNr">228 </span>  b0 20  <span class="subxComment"># al &lt;- 0x20</span>
+<span id="L229" class="LineNr">229 </span>  e6 20  <span class="subxComment"># port 0x20 &lt;- al</span>
+<span id="L230" class="LineNr">230 </span>  <span class="subxComment"># read status into eax</span>
+<span id="L231" class="LineNr">231 </span>  31 c0  <span class="subxComment"># eax &lt;- xor eax;  11/direct 000/r32/eax 000/rm32/eax</span>
+<span id="L232" class="LineNr">232 </span>  e4 64  <span class="subxComment"># al &lt;- port 0x64</span>
+<span id="L233" class="LineNr">233 </span>  <span class="subxComment"># if (status &amp; 0x1) == 0, return</span>
+<span id="L234" class="LineNr">234 </span>  24 01  <span class="subxComment"># al &lt;- and 0x1</span>
+<span id="L235" class="LineNr">235 </span>  3c 00  <span class="subxComment"># compare al, 0</span>
+<span id="L236" class="LineNr">236 </span>  74 2d  <span class="subxComment"># jump to epilogue if = [label]</span>
+<span id="L237" class="LineNr">237 </span><span class="subxComment"># 120:</span>
+<span id="L238" class="LineNr">238 </span>  <span class="subxComment"># if keyboard buffer is full, return</span>
+<span id="L239" class="LineNr">239 </span>  31 c9  <span class="subxComment"># ecx &lt;- xor ecx;  11/direct 001/r32/ecx 001/rm32/ecx</span>
+<span id="L240" class="LineNr">240 </span>  <span class="subxS1Comment"># . var index/ecx: byte</span>
+<span id="L241" class="LineNr">241 </span>  8a  <span class="subxComment"># copy m8 at r32 to r8</span>
+<span id="L242" class="LineNr">242 </span>    0d  <span class="subxComment"># 00/mod/indirect 001/r8/cl 101/rm32/use-disp32</span>
+<span id="L243" class="LineNr">243 </span>    ce 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L244" class="LineNr">244 </span>  <span class="subxS1Comment"># . al = *(keyboard buffer + index)</span>
+<span id="L245" class="LineNr">245 </span>  8a  <span class="subxComment"># copy m8 at r32 to r8</span>
+<span id="L246" class="LineNr">246 </span>    81  <span class="subxComment"># 10/mod/*+disp32 000/r8/al 001/rm32/ecx</span>
+<span id="L247" class="LineNr">247 </span>    d0 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L248" class="LineNr">248 </span>  <span class="subxS1Comment"># . if (al != 0) return</span>
+<span id="L249" class="LineNr">249 </span>  3c 00  <span class="subxComment"># compare al, 0</span>
+<span id="L250" class="LineNr">250 </span><span class="subxComment"># 130:</span>
+<span id="L251" class="LineNr">251 </span>  75 1b  <span class="subxComment"># jump to epilogue if != [label]</span>
+<span id="L252" class="LineNr">252 </span>  <span class="subxComment"># read keycode into al</span>
+<span id="L253" class="LineNr">253 </span>  e4 60  <span class="subxComment"># al &lt;- port 0x60</span>
+<span id="L254" class="LineNr">254 </span>  <span class="subxComment"># al &lt;- *(keyboard normal map + eax)</span>
+<span id="L255" class="LineNr">255 </span>  8a  <span class="subxComment"># copy m8 at rm32 to r8</span>
+<span id="L256" class="LineNr">256 </span>    80  <span class="subxComment"># 10/mod/*+disp32 000/r8/al 000/rm32/eax</span>
+<span id="L257" class="LineNr">257 </span>    00 80 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L258" class="LineNr">258 </span>  <span class="subxComment"># store al in keyboard buffer</span>
+<span id="L259" class="LineNr">259 </span>  88  <span class="subxComment"># copy r8 to m8 at r32</span>
+<span id="L260" class="LineNr">260 </span>    81  <span class="subxComment"># 10/mod/*+disp32 000/r8/al 001/rm32/ecx</span>
+<span id="L261" class="LineNr">261 </span>    d0 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L262" class="LineNr">262 </span><span class="subxComment"># 140:</span>
+<span id="L263" class="LineNr">263 </span>  <span class="subxComment"># increment index</span>
+<span id="L264" class="LineNr">264 </span>  fe  <span class="subxComment"># increment byte</span>
+<span id="L265" class="LineNr">265 </span>    05  <span class="subxComment"># 00/mod/indirect 000/subop/increment 101/rm32/use-disp32</span>
+<span id="L266" class="LineNr">266 </span>    ce 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L267" class="LineNr">267 </span>  <span class="subxComment"># clear top nibble of index (keyboard buffer is circular)</span>
+<span id="L268" class="LineNr">268 </span>  80  <span class="subxComment"># and byte</span>
+<span id="L269" class="LineNr">269 </span>    25  <span class="subxComment"># 00/mod/indirect 100/subop/and 101/rm32/use-disp32</span>
+<span id="L270" class="LineNr">270 </span>    ce 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L271" class="LineNr">271 </span>    0f  <span class="subxComment"># imm8</span>
+<span id="L272" class="LineNr">272 </span><span class="subxComment"># 14d:</span>
+<span id="L273" class="LineNr">273 </span>  <span class="subxComment"># epilogue</span>
+<span id="L274" class="LineNr">274 </span>  61  <span class="subxComment"># pop all registers</span>
+<span id="L275" class="LineNr">275 </span>  fb  <span class="subxComment"># enable interrupts</span>
+<span id="L276" class="LineNr">276 </span>  cf  <span class="subxComment"># iret</span>
+<span id="L277" class="LineNr">277 </span>
+<span id="L278" class="LineNr">278 </span><span class="subxComment"># padding</span>
+<span id="L279" class="LineNr">279 </span><span class="subxComment"># 150:</span>
+<span id="L280" class="LineNr">280 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L281" class="LineNr">281 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L282" class="LineNr">282 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L283" class="LineNr">283 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L284" class="LineNr">284 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L285" class="LineNr">285 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L286" class="LineNr">286 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L287" class="LineNr">287 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L288" class="LineNr">288 </span>
+<span id="L289" class="LineNr">289 </span><span class="subxComment"># 1ce:</span>
+<span id="L290" class="LineNr">290 </span><span class="subxComment"># var keyboard circular buffer</span>
+<span id="L291" class="LineNr">291 </span><span class="subxComment"># write index: nibble</span>
+<span id="L292" class="LineNr">292 </span>00
+<span id="L293" class="LineNr">293 </span><span class="subxComment"># 1cf:</span>
+<span id="L294" class="LineNr">294 </span><span class="subxComment"># read index: nibble</span>
+<span id="L295" class="LineNr">295 </span>00
+<span id="L296" class="LineNr">296 </span><span class="subxComment"># circular buffer: byte[16]</span>
+<span id="L297" class="LineNr">297 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L298" class="LineNr">298 </span>
+<span id="L299" class="LineNr">299 </span><span class="subxComment"># padding</span>
+<span id="L300" class="LineNr">300 </span><span class="subxComment"># 1e0:</span>
+<span id="L301" class="LineNr">301 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 <span id="L302" class="LineNr">302 </span>00 00 00 00 00 00 00 00
-<span id="L303" class="LineNr">303 </span>00 00 00 00 00 00 00 00
-<span id="L304" class="LineNr">304 </span>00 00 00 00 00 00 00 00
-<span id="L305" class="LineNr">305 </span>00 00 00 00 00 00 00 00
-<span id="L306" class="LineNr">306 </span>00 00 00 00 00 00 00 00
-<span id="L307" class="LineNr">307 </span>00 00 00 00 00 00 00 00
-<span id="L308" class="LineNr">308 </span>00 00 00 00 00 00 00 00
-<span id="L309" class="LineNr">309 </span>00 00 00 00 00 00 00 00
-<span id="L310" class="LineNr">310 </span>00 00 00 00 00 00 00 00
-<span id="L311" class="LineNr">311 </span>00 00 00 00 00 00 00 00
-<span id="L312" class="LineNr">312 </span><span class="subxComment"># idt_end:</span>
-<span id="L313" class="LineNr">313 </span>
-<span id="L314" class="LineNr">314 </span><span class="subxComment"># offset 300 (address 0x7f00):</span>
-<span id="L315" class="LineNr">315 </span><span class="subxComment"># idt_descriptor:</span>
-<span id="L316" class="LineNr">316 </span>  ff 00  <span class="subxComment"># idt_end - idt_start - 1</span>
-<span id="L317" class="LineNr">317 </span>  00 7e 00 00  <span class="subxComment"># start = idt_start</span>
-<span id="L318" class="LineNr">318 </span>
-<span id="L319" class="LineNr">319 </span><span class="subxComment"># padding</span>
-<span id="L320" class="LineNr">320 </span>                  00 00 00 00 00 00 00 00 00 00
-<span id="L321" class="LineNr">321 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L322" class="LineNr">322 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L323" class="LineNr">323 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L324" class="LineNr">324 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L325" class="LineNr">325 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L326" class="LineNr">326 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L327" class="LineNr">327 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L328" class="LineNr">328 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L329" class="LineNr">329 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L330" class="LineNr">330 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L331" class="LineNr">331 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L332" class="LineNr">332 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L333" class="LineNr">333 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L334" class="LineNr">334 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L335" class="LineNr">335 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
-<span id="L336" class="LineNr">336 </span><span class="subxComment"># offset 400 (address 0x8000)</span>
-<span id="L337" class="LineNr">337 </span>
-<span id="L338" class="LineNr">338 </span><span class="subxComment"># vim&#0058;ft=subx</span>
+<span id="L303" class="LineNr">303 </span>
+<span id="L304" class="LineNr">304 </span><span class="subxComment"># 1f8:</span>
+<span id="L305" class="LineNr">305 </span><span class="subxComment"># idt_descriptor:</span>
+<span id="L306" class="LineNr">306 </span>  ff 00  <span class="subxComment"># idt_end - idt_start - 1</span>
+<span id="L307" class="LineNr">307 </span>  00 7e 00 00  <span class="subxComment"># start = idt_start [label]</span>
+<span id="L308" class="LineNr">308 </span>
+<span id="L309" class="LineNr">309 </span><span class="subxComment"># 1fe:</span>
+<span id="L310" class="LineNr">310 </span><span class="subxComment"># final 2 bytes of boot sector</span>
+<span id="L311" class="LineNr">311 </span>55 aa
+<span id="L312" class="LineNr">312 </span>
+<span id="L313" class="LineNr">313 </span><span class="subxComment">## sector 2</span>
+<span id="L314" class="LineNr">314 </span><span class="subxComment"># loaded by load_disk, not automatically on boot</span>
+<span id="L315" class="LineNr">315 </span>
+<span id="L316" class="LineNr">316 </span><span class="subxComment"># offset 200 (address 0x7e00): interrupt descriptor table</span>
+<span id="L317" class="LineNr">317 </span><span class="subxComment"># 32 entries * 8 bytes each = 256 bytes (0x100)</span>
+<span id="L318" class="LineNr">318 </span><span class="subxComment"># idt_start:</span>
+<span id="L319" class="LineNr">319 </span>
+<span id="L320" class="LineNr">320 </span>00 00 00 00 00 00 00 00
+<span id="L321" class="LineNr">321 </span>00 00 00 00 00 00 00 00
+<span id="L322" class="LineNr">322 </span>00 00 00 00 00 00 00 00
+<span id="L323" class="LineNr">323 </span>00 00 00 00 00 00 00 00
+<span id="L324" class="LineNr">324 </span>00 00 00 00 00 00 00 00
+<span id="L325" class="LineNr">325 </span>00 00 00 00 00 00 00 00
+<span id="L326" class="LineNr">326 </span>00 00 00 00 00 00 00 00
+<span id="L327" class="LineNr">327 </span>00 00 00 00 00 00 00 00
+<span id="L328" class="LineNr">328 </span>
+<span id="L329" class="LineNr">329 </span><span class="subxComment"># entry 8: clock</span>
+<span id="L330" class="LineNr">330 </span>  00 7d  <span class="subxComment"># target[0:16] = null interrupt handler [label]</span>
+<span id="L331" class="LineNr">331 </span>  08 00  <span class="subxComment"># segment selector (gdt_code)</span>
+<span id="L332" class="LineNr">332 </span>  00  <span class="subxComment"># unused</span>
+<span id="L333" class="LineNr">333 </span>  8e  <span class="subxComment"># 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate</span>
+<span id="L334" class="LineNr">334 </span>  00 00  <span class="subxComment"># target[16:32]</span>
+<span id="L335" class="LineNr">335 </span>
+<span id="L336" class="LineNr">336 </span><span class="subxComment"># entry 9: keyboard</span>
+<span id="L337" class="LineNr">337 </span>  10 7d  <span class="subxComment"># target[0:16] = keyboard interrupt handler [label]</span>
+<span id="L338" class="LineNr">338 </span>  08 00  <span class="subxComment"># segment selector (gdt_code)</span>
+<span id="L339" class="LineNr">339 </span>  00  <span class="subxComment"># unused</span>
+<span id="L340" class="LineNr">340 </span>  8e  <span class="subxComment"># 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate</span>
+<span id="L341" class="LineNr">341 </span>  00 00  <span class="subxComment"># target[16:32]</span>
+<span id="L342" class="LineNr">342 </span>
+<span id="L343" class="LineNr">343 </span>00 00 00 00 00 00 00 00
+<span id="L344" class="LineNr">344 </span>00 00 00 00 00 00 00 00
+<span id="L345" class="LineNr">345 </span>00 00 00 00 00 00 00 00
+<span id="L346" class="LineNr">346 </span>00 00 00 00 00 00 00 00
+<span id="L347" class="LineNr">347 </span>00 00 00 00 00 00 00 00
+<span id="L348" class="LineNr">348 </span>00 00 00 00 00 00 00 00
+<span id="L349" class="LineNr">349 </span>00 00 00 00 00 00 00 00
+<span id="L350" class="LineNr">350 </span>00 00 00 00 00 00 00 00
+<span id="L351" class="LineNr">351 </span>00 00 00 00 00 00 00 00
+<span id="L352" class="LineNr">352 </span>00 00 00 00 00 00 00 00
+<span id="L353" class="LineNr">353 </span>00 00 00 00 00 00 00 00
+<span id="L354" class="LineNr">354 </span>00 00 00 00 00 00 00 00
+<span id="L355" class="LineNr">355 </span>00 00 00 00 00 00 00 00
+<span id="L356" class="LineNr">356 </span>00 00 00 00 00 00 00 00
+<span id="L357" class="LineNr">357 </span>00 00 00 00 00 00 00 00
+<span id="L358" class="LineNr">358 </span>00 00 00 00 00 00 00 00
+<span id="L359" class="LineNr">359 </span>00 00 00 00 00 00 00 00
+<span id="L360" class="LineNr">360 </span>00 00 00 00 00 00 00 00
+<span id="L361" class="LineNr">361 </span>00 00 00 00 00 00 00 00
+<span id="L362" class="LineNr">362 </span>00 00 00 00 00 00 00 00
+<span id="L363" class="LineNr">363 </span>00 00 00 00 00 00 00 00
+<span id="L364" class="LineNr">364 </span>00 00 00 00 00 00 00 00
+<span id="L365" class="LineNr">365 </span><span class="subxComment"># idt_end:</span>
+<span id="L366" class="LineNr">366 </span>
+<span id="L367" class="LineNr">367 </span><span class="subxComment"># offset 300 (address 0x7f00):</span>
+<span id="L368" class="LineNr">368 </span><span class="subxComment"># video mode info:</span>
+<span id="L369" class="LineNr">369 </span>  00 00  <span class="subxComment"># attributes</span>
+<span id="L370" class="LineNr">370 </span>  00  <span class="subxComment"># winA</span>
+<span id="L371" class="LineNr">371 </span>  00  <span class="subxComment"># winB</span>
+<span id="L372" class="LineNr">372 </span><span class="subxComment"># 304</span>
+<span id="L373" class="LineNr">373 </span>  00 00  <span class="subxComment"># granularity</span>
+<span id="L374" class="LineNr">374 </span>  00 00  <span class="subxComment"># winsize</span>
+<span id="L375" class="LineNr">375 </span><span class="subxComment"># 308</span>
+<span id="L376" class="LineNr">376 </span>  00 00  <span class="subxComment"># segmentA</span>
+<span id="L377" class="LineNr">377 </span>  00 00  <span class="subxComment"># segmentB</span>
+<span id="L378" class="LineNr">378 </span><span class="subxComment"># 30c</span>
+<span id="L379" class="LineNr">379 </span>  00 00 00 00  <span class="subxComment"># realFctPtr (who knows)</span>
+<span id="L380" class="LineNr">380 </span><span class="subxComment"># 310</span>
+<span id="L381" class="LineNr">381 </span>  00 00  <span class="subxComment"># pitch</span>
+<span id="L382" class="LineNr">382 </span>  00 00  <span class="subxComment"># Xres</span>
+<span id="L383" class="LineNr">383 </span><span class="subxComment"># 314</span>
+<span id="L384" class="LineNr">384 </span>  00 00  <span class="subxComment"># Yres</span>
+<span id="L385" class="LineNr">385 </span>  00 00  <span class="subxComment"># Wchar Ychar</span>
+<span id="L386" class="LineNr">386 </span><span class="subxComment"># 318</span>
+<span id="L387" class="LineNr">387 </span>  00  <span class="subxComment"># planes</span>
+<span id="L388" class="LineNr">388 </span>  00  <span class="subxComment"># bpp</span>
+<span id="L389" class="LineNr">389 </span>  00  <span class="subxComment"># banks</span>
+<span id="L390" class="LineNr">390 </span>  00  <span class="subxComment"># memory_model</span>
+<span id="L391" class="LineNr">391 </span><span class="subxComment"># 31c</span>
+<span id="L392" class="LineNr">392 </span>  00  <span class="subxComment"># bank_size</span>
+<span id="L393" class="LineNr">393 </span>  00  <span class="subxComment"># image_pages</span>
+<span id="L394" class="LineNr">394 </span>  00  <span class="subxComment"># reserved</span>
+<span id="L395" class="LineNr">395 </span><span class="subxComment"># 31f</span>
+<span id="L396" class="LineNr">396 </span>  00 00  <span class="subxComment"># red_mask red_position</span>
+<span id="L397" class="LineNr">397 </span>  00 00  <span class="subxComment"># green_mask green_position</span>
+<span id="L398" class="LineNr">398 </span>  00 00  <span class="subxComment"># blue_mask blue_position</span>
+<span id="L399" class="LineNr">399 </span>  00 00  <span class="subxComment"># rsv_mask rsv_position</span>
+<span id="L400" class="LineNr">400 </span>  00  <span class="subxComment"># directcolor_attributes</span>
+<span id="L401" class="LineNr">401 </span><span class="subxComment"># 328</span>
+<span id="L402" class="LineNr">402 </span>  00 00 00 00  <span class="subxComment"># physbase &lt;== linear frame buffer</span>
+<span id="L403" class="LineNr">403 </span>
+<span id="L404" class="LineNr">404 </span><span class="subxComment"># 32c</span>
+<span id="L405" class="LineNr">405 </span><span class="subxComment"># reserved for video mode info</span>
+<span id="L406" class="LineNr">406 </span>                                    00 00 00 00
+<span id="L407" class="LineNr">407 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L408" class="LineNr">408 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L409" class="LineNr">409 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L410" class="LineNr">410 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L411" class="LineNr">411 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L412" class="LineNr">412 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L413" class="LineNr">413 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L414" class="LineNr">414 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L415" class="LineNr">415 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L416" class="LineNr">416 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L417" class="LineNr">417 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L418" class="LineNr">418 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L419" class="LineNr">419 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L420" class="LineNr">420 </span>
+<span id="L421" class="LineNr">421 </span><span class="subxComment"># offset 400 (address 0x8000):</span>
+<span id="L422" class="LineNr">422 </span><span class="subxComment"># keyboard normal map:</span>
+<span id="L423" class="LineNr">423 </span>00
+<span id="L424" class="LineNr">424 </span><span class="subxComment">#  es</span>
+<span id="L425" class="LineNr">425 </span>   1b
+<span id="L426" class="LineNr">426 </span><span class="subxComment">#     |&lt;--- digits --------------&gt;| -  =  bs</span>
+<span id="L427" class="LineNr">427 </span>      31 32 33 34 35 36 37 38 39 30 2d 3d 08
+<span id="L428" class="LineNr">428 </span><span class="subxComment"># offset 40f</span>
+<span id="L429" class="LineNr">429 </span><span class="subxComment">#  tb q  w  e  r  t  y  u  i  o  p  [  ]</span>
+<span id="L430" class="LineNr">430 </span>   09 71 77 65 72 74 79 75 69 6f 70 5b 5d
+<span id="L431" class="LineNr">431 </span><span class="subxComment"># offset 41c</span>
+<span id="L432" class="LineNr">432 </span><span class="subxComment">#                                         enter</span>
+<span id="L433" class="LineNr">433 </span>                                          0a 00
+<span id="L434" class="LineNr">434 </span><span class="subxComment"># offset 41e</span>
+<span id="L435" class="LineNr">435 </span><span class="subxComment">#     a  s  d  f  g  h  j  k  l  ;  '  `     \</span>
+<span id="L436" class="LineNr">436 </span>      61 73 64 66 67 68 6a 6b 6c 3b 27 60 00 5c
+<span id="L437" class="LineNr">437 </span><span class="subxComment"># offset 42c</span>
+<span id="L438" class="LineNr">438 </span><span class="subxComment">#     z  x  c  v  b  n  m  ,  .  /</span>
+<span id="L439" class="LineNr">439 </span>      7a 78 63 76 62 6e 6d 2c 2e 2f
+<span id="L440" class="LineNr">440 </span><span class="subxComment"># offset 436</span>
+<span id="L441" class="LineNr">441 </span>                  00 00 00 00 00 00 00 00 00 00
+<span id="L442" class="LineNr">442 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L443" class="LineNr">443 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L444" class="LineNr">444 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L445" class="LineNr">445 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L446" class="LineNr">446 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L447" class="LineNr">447 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L448" class="LineNr">448 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L449" class="LineNr">449 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L450" class="LineNr">450 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L451" class="LineNr">451 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L452" class="LineNr">452 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L453" class="LineNr">453 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L454" class="LineNr">454 </span>
+<span id="L455" class="LineNr">455 </span><span class="subxComment"># 500:</span>
+<span id="L456" class="LineNr">456 </span><span class="subxComment"># keyboard shift map:</span>
+<span id="L457" class="LineNr">457 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L458" class="LineNr">458 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L459" class="LineNr">459 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L460" class="LineNr">460 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L461" class="LineNr">461 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L462" class="LineNr">462 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L463" class="LineNr">463 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L464" class="LineNr">464 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L465" class="LineNr">465 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L466" class="LineNr">466 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L467" class="LineNr">467 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L468" class="LineNr">468 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L469" class="LineNr">469 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L470" class="LineNr">470 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L471" class="LineNr">471 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L472" class="LineNr">472 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L473" class="LineNr">473 </span>
+<span id="L474" class="LineNr">474 </span><span class="subxComment"># 600:</span>
+<span id="L475" class="LineNr">475 </span><span class="subxComment"># keyboard ctrl map:</span>
+<span id="L476" class="LineNr">476 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L477" class="LineNr">477 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L478" class="LineNr">478 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L479" class="LineNr">479 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L480" class="LineNr">480 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L481" class="LineNr">481 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L482" class="LineNr">482 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L483" class="LineNr">483 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L484" class="LineNr">484 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L485" class="LineNr">485 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L486" class="LineNr">486 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L487" class="LineNr">487 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L488" class="LineNr">488 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L489" class="LineNr">489 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L490" class="LineNr">490 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L491" class="LineNr">491 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L492" class="LineNr">492 </span>
+<span id="L493" class="LineNr">493 </span><span class="subxComment"># padding (there might be more keyboard tables)</span>
+<span id="L494" class="LineNr">494 </span><span class="subxComment"># 700:</span>
+<span id="L495" class="LineNr">495 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L496" class="LineNr">496 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L497" class="LineNr">497 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L498" class="LineNr">498 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L499" class="LineNr">499 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L500" class="LineNr">500 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L501" class="LineNr">501 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L502" class="LineNr">502 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L503" class="LineNr">503 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L504" class="LineNr">504 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L505" class="LineNr">505 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L506" class="LineNr">506 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L507" class="LineNr">507 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L508" class="LineNr">508 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L509" class="LineNr">509 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L510" class="LineNr">510 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L511" class="LineNr">511 </span>
+<span id="L512" class="LineNr">512 </span><span class="subxComment"># 800:</span>
+<span id="L513" class="LineNr">513 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L514" class="LineNr">514 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L515" class="LineNr">515 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L516" class="LineNr">516 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L517" class="LineNr">517 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L518" class="LineNr">518 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L519" class="LineNr">519 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L520" class="LineNr">520 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L521" class="LineNr">521 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L522" class="LineNr">522 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L523" class="LineNr">523 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L524" class="LineNr">524 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L525" class="LineNr">525 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L526" class="LineNr">526 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L527" class="LineNr">527 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L528" class="LineNr">528 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L529" class="LineNr">529 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L530" class="LineNr">530 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L531" class="LineNr">531 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L532" class="LineNr">532 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L533" class="LineNr">533 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L534" class="LineNr">534 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L535" class="LineNr">535 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L536" class="LineNr">536 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L537" class="LineNr">537 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L538" class="LineNr">538 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L539" class="LineNr">539 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L540" class="LineNr">540 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L541" class="LineNr">541 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L542" class="LineNr">542 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L543" class="LineNr">543 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L544" class="LineNr">544 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L545" class="LineNr">545 </span><span class="subxComment"># a00:</span>
+<span id="L546" class="LineNr">546 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L547" class="LineNr">547 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L548" class="LineNr">548 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L549" class="LineNr">549 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L550" class="LineNr">550 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L551" class="LineNr">551 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L552" class="LineNr">552 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L553" class="LineNr">553 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L554" class="LineNr">554 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L555" class="LineNr">555 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L556" class="LineNr">556 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L557" class="LineNr">557 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L558" class="LineNr">558 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L559" class="LineNr">559 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L560" class="LineNr">560 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L561" class="LineNr">561 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L562" class="LineNr">562 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L563" class="LineNr">563 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L564" class="LineNr">564 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L565" class="LineNr">565 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L566" class="LineNr">566 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L567" class="LineNr">567 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L568" class="LineNr">568 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L569" class="LineNr">569 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L570" class="LineNr">570 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L571" class="LineNr">571 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L572" class="LineNr">572 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L573" class="LineNr">573 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L574" class="LineNr">574 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L575" class="LineNr">575 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L576" class="LineNr">576 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L577" class="LineNr">577 </span>00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+<span id="L578" class="LineNr">578 </span><span class="subxComment"># offset c00 (address 0x8800)</span>
+<span id="L579" class="LineNr">579 </span>
+<span id="L580" class="LineNr">580 </span><span class="subxComment"># vim&#0058;ft=subx</span>
 </pre>
 </body>
 </html>
diff --git a/html/baremetal/ex2.hex.html b/html/baremetal/ex2.hex.html
index 008f2dd3..42eae7b3 100644
--- a/html/baremetal/ex2.hex.html
+++ b/html/baremetal/ex2.hex.html
@@ -68,7 +68,7 @@ if ('onhashchange' in window) {
 <span id="L15" class="LineNr">15 </span><span class="subxComment"># ecx &lt;- LFB</span>
 <span id="L16" class="LineNr">16 </span>8b  <span class="subxComment"># copy *rm32 to r32</span>
 <span id="L17" class="LineNr">17 </span>  0d  <span class="subxComment"># 00/mod/indirect 001/r32/ecx 101/rm32/use-disp32</span>
-<span id="L18" class="LineNr">18 </span>  68 7d 00 00 <span class="subxComment"># disp32</span>
+<span id="L18" class="LineNr">18 </span>  28 7f 00 00 <span class="subxComment"># disp32 [label]</span>
 <span id="L19" class="LineNr">19 </span>
 <span id="L20" class="LineNr">20 </span><span class="subxComment"># eax &lt;- LFB + 0xbffff (1024*768 - 1)</span>
 <span id="L21" class="LineNr">21 </span>8d  <span class="subxComment"># copy-address rm32 to r32</span>
@@ -79,12 +79,12 @@ if ('onhashchange' in window) {
 <span id="L26" class="LineNr">26 </span><span class="subxComment"># if (eax &lt; ecx) break</span>
 <span id="L27" class="LineNr">27 </span>39  <span class="subxComment"># compare rm32 with r32</span>
 <span id="L28" class="LineNr">28 </span>  c8  <span class="subxComment"># 11/mod/direct 001/r32/ecx 000/rm32/eax</span>
-<span id="L29" class="LineNr">29 </span>7c 05  <span class="subxComment"># break if &lt;</span>
+<span id="L29" class="LineNr">29 </span>7c 05  <span class="subxComment"># break if &lt; [label]</span>
 <span id="L30" class="LineNr">30 </span><span class="subxComment"># *eax &lt;- al</span>
 <span id="L31" class="LineNr">31 </span>88  <span class="subxComment"># copy r8 to m8 at r32</span>
 <span id="L32" class="LineNr">32 </span>  00  <span class="subxComment"># 00/mod/indirect 000/r8/AL 000/rm32/eax</span>
 <span id="L33" class="LineNr">33 </span>48  <span class="subxComment"># decrement eax</span>
-<span id="L34" class="LineNr">34 </span>eb f7  <span class="subxComment"># loop to -9 bytes</span>
+<span id="L34" class="LineNr">34 </span>eb f7  <span class="subxComment"># loop to -9 bytes [label]</span>
 <span id="L35" class="LineNr">35 </span>
 <span id="L36" class="LineNr">36 </span><span class="subxComment"># $break:</span>
 <span id="L37" class="LineNr">37 </span>e9 fb ff ff ff  <span class="subxComment"># hang indefinitely</span>
diff --git a/html/baremetal/ex3.hex.html b/html/baremetal/ex3.hex.html
new file mode 100644
index 00000000..ccb3422c
--- /dev/null
+++ b/html/baremetal/ex3.hex.html
@@ -0,0 +1,114 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<html>
+<head>
+<meta http-equiv="content-type" content="text/html; charset=UTF-8">
+<title>Mu - baremetal/ex3.hex</title>
+<meta name="Generator" content="Vim/8.1">
+<meta name="plugin-version" content="vim8.1_v1">
+<meta name="syntax" content="none">
+<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
+<meta name="colorscheme" content="minimal-light">
+<style type="text/css">
+<!--
+pre { white-space: pre-wrap; font-family: monospace; color: #000000; background-color: #c6c6c6; }
+body { font-size:12pt; font-family: monospace; color: #000000; background-color: #c6c6c6; }
+a { color:inherit; }
+* { font-size:12pt; font-size: 1em; }
+.subxComment { color: #005faf; }
+.LineNr { }
+-->
+</style>
+
+<script type='text/javascript'>
+<!--
+
+/* function to open any folds containing a jumped-to line before jumping to it */
+function JumpToLine()
+{
+  var lineNum;
+  lineNum = window.location.hash;
+  lineNum = lineNum.substr(1); /* strip off '#' */
+
+  if (lineNum.indexOf('L') == -1) {
+    lineNum = 'L'+lineNum;
+  }
+  var lineElem = document.getElementById(lineNum);
+  /* Always jump to new location even if the line was hidden inside a fold, or
+   * we corrected the raw number to a line ID.
+   */
+  if (lineElem) {
+    lineElem.scrollIntoView(true);
+  }
+  return true;
+}
+if ('onhashchange' in window) {
+  window.onhashchange = JumpToLine;
+}
+
+-->
+</script>
+</head>
+<body onload='JumpToLine();'>
+<a href='https://github.com/akkartik/mu/blob/master/baremetal/ex3.hex'>https://github.com/akkartik/mu/blob/master/baremetal/ex3.hex</a>
+<pre id='vimCodeElement'>
+<span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Draw pixels in response to keyboard events.</span>
+<span id="L2" class="LineNr"> 2 </span><span class="subxComment">#</span>
+<span id="L3" class="LineNr"> 3 </span><span class="subxComment"># To run, first prepare a realistically sized disk image:</span>
+<span id="L4" class="LineNr"> 4 </span><span class="subxComment">#   dd if=/dev/zero of=disk.img count=20160  # 512-byte sectors, so 10MB</span>
+<span id="L5" class="LineNr"> 5 </span><span class="subxComment"># Load the program on the disk image:</span>
+<span id="L6" class="LineNr"> 6 </span><span class="subxComment">#   cat baremetal/boot.hex baremetal/ex3.hex  |./bootstrap run apps/hex  &gt; a.bin</span>
+<span id="L7" class="LineNr"> 7 </span><span class="subxComment">#   dd if=a.bin of=disk.img conv=notrunc</span>
+<span id="L8" class="LineNr"> 8 </span><span class="subxComment"># To run:</span>
+<span id="L9" class="LineNr"> 9 </span><span class="subxComment">#   qemu-system-i386 disk.img</span>
+<span id="L10" class="LineNr">10 </span><span class="subxComment"># Or:</span>
+<span id="L11" class="LineNr">11 </span><span class="subxComment">#   bochs -f apps/boot.bochsrc  # boot.bochsrc loads disk.img</span>
+<span id="L12" class="LineNr">12 </span>
+<span id="L13" class="LineNr">13 </span><span class="subxComment"># main:  (address 0x8800)</span>
+<span id="L14" class="LineNr">14 </span>
+<span id="L15" class="LineNr">15 </span><span class="subxComment"># eax &lt;- LFB</span>
+<span id="L16" class="LineNr">16 </span>8b  <span class="subxComment"># copy *rm32 to r32</span>
+<span id="L17" class="LineNr">17 </span>  05  <span class="subxComment"># 00/mod/indirect 000/r32/eax 101/rm32/use-disp32</span>
+<span id="L18" class="LineNr">18 </span>  28 7f 00 00 <span class="subxComment"># disp32 [label]</span>
+<span id="L19" class="LineNr">19 </span>
+<span id="L20" class="LineNr">20 </span><span class="subxComment"># var read index/ecx: byte = 0</span>
+<span id="L21" class="LineNr">21 </span>31 c9  <span class="subxComment"># ecx &lt;- xor ecx;  11/direct 001/r32/ecx 001/rm32/ecx</span>
+<span id="L22" class="LineNr">22 </span>
+<span id="L23" class="LineNr">23 </span><span class="subxComment"># $loop:</span>
+<span id="L24" class="LineNr">24 </span>  <span class="subxComment"># CL = *read index</span>
+<span id="L25" class="LineNr">25 </span>  8a  <span class="subxComment"># copy m8 at r32 to r8</span>
+<span id="L26" class="LineNr">26 </span>    0d  <span class="subxComment"># 00/mod/indirect 001/r8/cl 101/rm32/use-disp32</span>
+<span id="L27" class="LineNr">27 </span>    cf 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L28" class="LineNr">28 </span>  <span class="subxComment"># CL = *(keyboard buffer + ecx)</span>
+<span id="L29" class="LineNr">29 </span>  8a  <span class="subxComment"># copy m8 at r32 to r8</span>
+<span id="L30" class="LineNr">30 </span>    89  <span class="subxComment"># 10/mod/*+disp32 001/r8/cl 001/rm32/ecx</span>
+<span id="L31" class="LineNr">31 </span>    d0 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L32" class="LineNr">32 </span>  <span class="subxComment"># if (CL == 0) loop (spin loop)</span>
+<span id="L33" class="LineNr">33 </span>  80
+<span id="L34" class="LineNr">34 </span>    f9  <span class="subxComment"># 11/mod/direct 111/subop/compare 001/rm8/CL</span>
+<span id="L35" class="LineNr">35 </span>    00  <span class="subxComment"># imm8</span>
+<span id="L36" class="LineNr">36 </span>  74 ef  <span class="subxComment"># loop -17 [label]</span>
+<span id="L37" class="LineNr">37 </span><span class="subxComment"># offset 0x19:</span>
+<span id="L38" class="LineNr">38 </span>  <span class="subxComment"># otherwise increment read index</span>
+<span id="L39" class="LineNr">39 </span>  fe  <span class="subxComment"># increment byte</span>
+<span id="L40" class="LineNr">40 </span>    05  <span class="subxComment"># 00/mod/indirect 000/subop/increment 101/rm32/use-disp32</span>
+<span id="L41" class="LineNr">41 </span>    cf 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L42" class="LineNr">42 </span>  <span class="subxComment"># clear top nibble of index (keyboard buffer is circular)</span>
+<span id="L43" class="LineNr">43 </span>  80  <span class="subxComment"># and byte</span>
+<span id="L44" class="LineNr">44 </span>    25  <span class="subxComment"># 00/mod/indirect 100/subop/and 101/rm32/use-disp32</span>
+<span id="L45" class="LineNr">45 </span>    cf 7d 00 00  <span class="subxComment"># disp32 [label]</span>
+<span id="L46" class="LineNr">46 </span>    0f  <span class="subxComment"># imm8</span>
+<span id="L47" class="LineNr">47 </span>  <span class="subxComment"># print a pixel in fluorescent green</span>
+<span id="L48" class="LineNr">48 </span>  c6  <span class="subxComment"># copy imm8 to m8 at rm32</span>
+<span id="L49" class="LineNr">49 </span>    00  <span class="subxComment"># 00/mod/indirect 000/subop 000/rm32/eax</span>
+<span id="L50" class="LineNr">50 </span>    31  <span class="subxComment"># imm32</span>
+<span id="L51" class="LineNr">51 </span>  40  <span class="subxComment"># increment eax</span>
+<span id="L52" class="LineNr">52 </span>  eb dc <span class="subxComment"># loop -36 [label]</span>
+<span id="L53" class="LineNr">53 </span>
+<span id="L54" class="LineNr">54 </span><span class="subxComment"># $break:</span>
+<span id="L55" class="LineNr">55 </span>e9 fb ff ff ff  <span class="subxComment"># hang indefinitely</span>
+<span id="L56" class="LineNr">56 </span>
+<span id="L57" class="LineNr">57 </span><span class="subxComment"># vim&#0058;ft=subx</span>
+</pre>
+</body>
+</html>
+<!-- vim: set foldmethod=manual : -->