diff options
author | Kartik Agaram <vc@akkartik.com> | 2019-12-28 00:02:29 -0800 |
---|---|---|
committer | Kartik Agaram <vc@akkartik.com> | 2019-12-28 00:02:29 -0800 |
commit | 03a1de45367ad0c52e6da03fcf56bfbee60a0ed3 (patch) | |
tree | 02180e96fbdf2b3b822083a334c7b49ce8d39a01 /html/050_write.subx.html | |
parent | 2b665cc552a4d98337bfdf87c17390b9dcb9ba9e (diff) | |
download | mu-03a1de45367ad0c52e6da03fcf56bfbee60a0ed3.tar.gz |
5835
Diffstat (limited to 'html/050_write.subx.html')
-rw-r--r-- | html/050_write.subx.html | 113 |
1 files changed, 58 insertions, 55 deletions
diff --git a/html/050_write.subx.html b/html/050_write.subx.html index 71734034..c12ebd44 100644 --- a/html/050_write.subx.html +++ b/html/050_write.subx.html @@ -79,61 +79,64 @@ if ('onhashchange' in window) { <span id="L20" class="LineNr">20 </span><span class="subxComment"># - 'ref' which is used to point to a unique element, because machine</span> <span id="L21" class="LineNr">21 </span><span class="subxComment"># code can't store large types in registers.</span> <span id="L22" class="LineNr">22 </span><span class="subxComment"># - 'handle' which can point to a heap allocation, different heap allocations</span> -<span id="L23" class="LineNr">23 </span><span class="subxComment"># at different times, or even at times nothing at all.</span> -<span id="L24" class="LineNr">24 </span><span class="subxComment">#</span> -<span id="L25" class="LineNr">25 </span><span class="subxComment"># The type 'address' can be obtained from either a ref or handle, but it can</span> -<span id="L26" class="LineNr">26 </span><span class="subxComment"># only be stored on the stack (say to pass objects by reference).</span> -<span id="L27" class="LineNr">27 </span><span class="subxComment"># Conversely, a ref can't be copied into another ref, only to an address (which</span> -<span id="L28" class="LineNr">28 </span><span class="subxComment"># by construction has a shorter lifetime).</span> -<span id="L29" class="LineNr">29 </span><span class="subxComment">#</span> -<span id="L30" class="LineNr">30 </span><span class="subxComment"># Beginnings of a lattice of types:</span> -<span id="L31" class="LineNr">31 </span><span class="subxComment"># You can convert a ref or handle to an address, but not the other way around.</span> -<span id="L32" class="LineNr">32 </span><span class="subxComment"># You can convert addresses to ints, but not the other way around.</span> -<span id="L33" class="LineNr">33 </span> -<span id="L34" class="LineNr">34 </span><span class="subxMinorFunction">_write</span>: <span class="subxComment"># fd : int, s : (address array byte)</span> -<span id="L35" class="LineNr">35 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L36" class="LineNr">36 </span> 55/push-ebp -<span id="L37" class="LineNr">37 </span> 89/copy 3/mod/direct 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/esp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy esp to ebp</span> -<span id="L38" class="LineNr">38 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L39" class="LineNr">39 </span> 50/push-eax -<span id="L40" class="LineNr">40 </span> 51/push-ecx -<span id="L41" class="LineNr">41 </span> 52/push-edx -<span id="L42" class="LineNr">42 </span> 53/push-ebx -<span id="L43" class="LineNr">43 </span> <span class="subxComment"># syscall(write, fd, (data) s+4, (size) *s)</span> -<span id="L44" class="LineNr">44 </span> <span class="subxS1Comment"># . fd : ebx</span> -<span id="L45" class="LineNr">45 </span> 8b/copy 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 3/r32/ebx 8/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(ebp+8) to ebx</span> -<span id="L46" class="LineNr">46 </span> <span class="subxS1Comment"># . data : ecx = s+4</span> -<span id="L47" class="LineNr">47 </span> 8b/copy 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 1/r32/ecx 0xc/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(ebp+12) to ecx</span> -<span id="L48" class="LineNr">48 </span> 81 0/subop/add 3/mod/direct 1/rm32/ecx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/imm32 <span class="subxComment"># add to ecx</span> -<span id="L49" class="LineNr">49 </span> <span class="subxS1Comment"># . size : edx = *s</span> -<span id="L50" class="LineNr">50 </span> 8b/copy 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/edx 0xc/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(ebp+12) to edx</span> -<span id="L51" class="LineNr">51 </span> 8b/copy 0/mod/indirect 2/rm32/edx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/edx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy *edx to edx</span> -<span id="L52" class="LineNr">52 </span> <span class="subxS1Comment"># . syscall</span> -<span id="L53" class="LineNr">53 </span> b8/copy-to-eax 4/imm32/write -<span id="L54" class="LineNr">54 </span> cd/syscall 0x80/imm8 -<span id="L55" class="LineNr">55 </span> <span class="subxComment"># if (eax < 0) abort</span> -<span id="L56" class="LineNr">56 </span> 3d/compare-eax-with 0/imm32 -<span id="L57" class="LineNr">57 </span> 0f 8c/jump-if-lesser $_write:abort/disp32 -<span id="L58" class="LineNr">58 </span><span class="Constant">$_write:end</span>: -<span id="L59" class="LineNr">59 </span> <span class="subxS1Comment"># . restore registers</span> -<span id="L60" class="LineNr">60 </span> 5b/pop-to-ebx -<span id="L61" class="LineNr">61 </span> 5a/pop-to-edx -<span id="L62" class="LineNr">62 </span> 59/pop-to-ecx -<span id="L63" class="LineNr">63 </span> 58/pop-to-eax -<span id="L64" class="LineNr">64 </span> <span class="subxS1Comment"># . epilogue</span> -<span id="L65" class="LineNr">65 </span> 89/copy 3/mod/direct 4/rm32/esp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 5/r32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ebp to esp</span> -<span id="L66" class="LineNr">66 </span> 5d/pop-to-ebp -<span id="L67" class="LineNr">67 </span> c3/return -<span id="L68" class="LineNr">68 </span> -<span id="L69" class="LineNr">69 </span><span class="Constant">$_write:abort</span>: -<span id="L70" class="LineNr">70 </span> <span class="subxComment"># can't write a message here for risk of an infinite loop, so we'll use a special exit code instead</span> -<span id="L71" class="LineNr">71 </span> <span class="subxS1Comment"># . syscall(exit, 255)</span> -<span id="L72" class="LineNr">72 </span> bb/copy-to-ebx 0xff/imm32 -<span id="L73" class="LineNr">73 </span> b8/copy-to-eax 1/imm32/exit -<span id="L74" class="LineNr">74 </span> cd/syscall 0x80/imm8 -<span id="L75" class="LineNr">75 </span> <span class="subxComment"># never gets here</span> -<span id="L76" class="LineNr">76 </span> -<span id="L77" class="LineNr">77 </span><span class="subxS2Comment"># . . vim:nowrap:textwidth=0</span> +<span id="L23" class="LineNr">23 </span><span class="subxComment"># at different times, or even at times nothing at all. (Later on handles</span> +<span id="L24" class="LineNr">24 </span><span class="subxComment"># will turn into fat pointers to enable safe reclamation. But in unsafe</span> +<span id="L25" class="LineNr">25 </span><span class="subxComment"># levels we'll just never reclaim them, and handles will be word-sized just</span> +<span id="L26" class="LineNr">26 </span><span class="subxComment"># like refs.)</span> +<span id="L27" class="LineNr">27 </span><span class="subxComment">#</span> +<span id="L28" class="LineNr">28 </span><span class="subxComment"># The type 'address' can be obtained from either a ref or handle, but it can</span> +<span id="L29" class="LineNr">29 </span><span class="subxComment"># only be stored on the stack (say to pass objects by reference).</span> +<span id="L30" class="LineNr">30 </span><span class="subxComment"># Conversely, a ref can't be copied into another ref, only to an address (which</span> +<span id="L31" class="LineNr">31 </span><span class="subxComment"># by construction has a shorter lifetime).</span> +<span id="L32" class="LineNr">32 </span><span class="subxComment">#</span> +<span id="L33" class="LineNr">33 </span><span class="subxComment"># Beginnings of a lattice of types:</span> +<span id="L34" class="LineNr">34 </span><span class="subxComment"># You can convert a ref or handle to an address, but not the other way around.</span> +<span id="L35" class="LineNr">35 </span><span class="subxComment"># You can convert addresses to ints, but not the other way around.</span> +<span id="L36" class="LineNr">36 </span> +<span id="L37" class="LineNr">37 </span><span class="subxMinorFunction">_write</span>: <span class="subxComment"># fd : int, s : (address array byte)</span> +<span id="L38" class="LineNr">38 </span> <span class="subxS1Comment"># . prologue</span> +<span id="L39" class="LineNr">39 </span> 55/push-ebp +<span id="L40" class="LineNr">40 </span> 89/copy 3/mod/direct 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/esp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy esp to ebp</span> +<span id="L41" class="LineNr">41 </span> <span class="subxS1Comment"># . save registers</span> +<span id="L42" class="LineNr">42 </span> 50/push-eax +<span id="L43" class="LineNr">43 </span> 51/push-ecx +<span id="L44" class="LineNr">44 </span> 52/push-edx +<span id="L45" class="LineNr">45 </span> 53/push-ebx +<span id="L46" class="LineNr">46 </span> <span class="subxComment"># syscall(write, fd, (data) s+4, (size) *s)</span> +<span id="L47" class="LineNr">47 </span> <span class="subxS1Comment"># . fd : ebx</span> +<span id="L48" class="LineNr">48 </span> 8b/copy 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 3/r32/ebx 8/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(ebp+8) to ebx</span> +<span id="L49" class="LineNr">49 </span> <span class="subxS1Comment"># . data : ecx = s+4</span> +<span id="L50" class="LineNr">50 </span> 8b/copy 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 1/r32/ecx 0xc/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(ebp+12) to ecx</span> +<span id="L51" class="LineNr">51 </span> 81 0/subop/add 3/mod/direct 1/rm32/ecx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/imm32 <span class="subxComment"># add to ecx</span> +<span id="L52" class="LineNr">52 </span> <span class="subxS1Comment"># . size : edx = *s</span> +<span id="L53" class="LineNr">53 </span> 8b/copy 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/edx 0xc/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(ebp+12) to edx</span> +<span id="L54" class="LineNr">54 </span> 8b/copy 0/mod/indirect 2/rm32/edx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/edx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy *edx to edx</span> +<span id="L55" class="LineNr">55 </span> <span class="subxS1Comment"># . syscall</span> +<span id="L56" class="LineNr">56 </span> b8/copy-to-eax 4/imm32/write +<span id="L57" class="LineNr">57 </span> cd/syscall 0x80/imm8 +<span id="L58" class="LineNr">58 </span> <span class="subxComment"># if (eax < 0) abort</span> +<span id="L59" class="LineNr">59 </span> 3d/compare-eax-with 0/imm32 +<span id="L60" class="LineNr">60 </span> 0f 8c/jump-if-lesser $_write:abort/disp32 +<span id="L61" class="LineNr">61 </span><span class="Constant">$_write:end</span>: +<span id="L62" class="LineNr">62 </span> <span class="subxS1Comment"># . restore registers</span> +<span id="L63" class="LineNr">63 </span> 5b/pop-to-ebx +<span id="L64" class="LineNr">64 </span> 5a/pop-to-edx +<span id="L65" class="LineNr">65 </span> 59/pop-to-ecx +<span id="L66" class="LineNr">66 </span> 58/pop-to-eax +<span id="L67" class="LineNr">67 </span> <span class="subxS1Comment"># . epilogue</span> +<span id="L68" class="LineNr">68 </span> 89/copy 3/mod/direct 4/rm32/esp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 5/r32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ebp to esp</span> +<span id="L69" class="LineNr">69 </span> 5d/pop-to-ebp +<span id="L70" class="LineNr">70 </span> c3/return +<span id="L71" class="LineNr">71 </span> +<span id="L72" class="LineNr">72 </span><span class="Constant">$_write:abort</span>: +<span id="L73" class="LineNr">73 </span> <span class="subxComment"># can't write a message here for risk of an infinite loop, so we'll use a special exit code instead</span> +<span id="L74" class="LineNr">74 </span> <span class="subxS1Comment"># . syscall(exit, 255)</span> +<span id="L75" class="LineNr">75 </span> bb/copy-to-ebx 0xff/imm32 +<span id="L76" class="LineNr">76 </span> b8/copy-to-eax 1/imm32/exit +<span id="L77" class="LineNr">77 </span> cd/syscall 0x80/imm8 +<span id="L78" class="LineNr">78 </span> <span class="subxComment"># never gets here</span> +<span id="L79" class="LineNr">79 </span> +<span id="L80" class="LineNr">80 </span><span class="subxS2Comment"># . . vim:nowrap:textwidth=0</span> </pre> </body> </html> |