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| author | Kartik Agaram <vc@akkartik.com> | 2021-03-23 17:31:08 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2021-03-23 17:31:08 -0700 |
| commit | 3350c34a74844e21ea69077e01efff3bae64bdcd (patch) | |
| tree | fa06ba58542297d1cff6b78958d4547a40a25d21 /html/linux/ex8.subx.html | |
| parent | 62a244211024a8367332541c571621883c05bcce (diff) | |
| download | mu-3350c34a74844e21ea69077e01efff3bae64bdcd.tar.gz | |
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Diffstat (limited to 'html/linux/ex8.subx.html')
| -rw-r--r-- | html/linux/ex8.subx.html | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/html/linux/ex8.subx.html b/html/linux/ex8.subx.html new file mode 100644 index 00000000..c30fac4f --- /dev/null +++ b/html/linux/ex8.subx.html @@ -0,0 +1,123 @@ +<!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 - linux/ex8.subx</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,no_foldcolumn,expand_tabs,line_ids,prevent_copy="> +<meta name="colorscheme" content="minimal-light"> +<style type="text/css"> +<!-- +pre { 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; } +.subxS1Comment { color: #0000af; } +.subxS2Comment { color: #8a8a8a; } +.LineNr { } +.Constant { color: #008787; } +.SpecialChar { color: #d70000; } +.Normal { color: #000000; background-color: #c6c6c6; padding-bottom: 1px; } +.subxFunction { color: #af5f00; text-decoration: underline; } +--> +</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/main/linux/ex8.subx'>https://github.com/akkartik/mu/blob/main/linux/ex8.subx</a> +<pre id='vimCodeElement'> +<span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Example reading commandline arguments: compute length of first arg.</span> +<span id="L2" class="LineNr"> 2 </span><span class="subxComment">#</span> +<span id="L3" class="LineNr"> 3 </span><span class="subxComment"># To run:</span> +<span id="L4" class="LineNr"> 4 </span><span class="subxComment"># $ bootstrap/bootstrap translate apps/ex8.subx -o apps/ex8</span> +<span id="L5" class="LineNr"> 5 </span><span class="subxComment"># $ bootstrap/bootstrap run ex8 abc de fghi</span> +<span id="L6" class="LineNr"> 6 </span><span class="subxComment"># Expected result:</span> +<span id="L7" class="LineNr"> 7 </span><span class="subxComment"># $ echo $?</span> +<span id="L8" class="LineNr"> 8 </span><span class="subxComment"># 3 # length of 'abc'</span> +<span id="L9" class="LineNr"> 9 </span><span class="subxComment">#</span> +<span id="L10" class="LineNr">10 </span><span class="subxComment"># At the start of a SubX program:</span> +<span id="L11" class="LineNr">11 </span><span class="subxComment"># argc: *esp</span> +<span id="L12" class="LineNr">12 </span><span class="subxComment"># argv[0]: *(esp+4)</span> +<span id="L13" class="LineNr">13 </span><span class="subxComment"># argv[1]: *(esp+8)</span> +<span id="L14" class="LineNr">14 </span><span class="subxComment"># ...</span> +<span id="L15" class="LineNr">15 </span><span class="subxComment"># Locals start from esp-4 downwards.</span> +<span id="L16" class="LineNr">16 </span> +<span id="L17" class="LineNr">17 </span>== code +<span id="L18" class="LineNr">18 </span><span class="subxComment"># instruction effective address register displacement immediate</span> +<span id="L19" class="LineNr">19 </span><span class="subxS1Comment"># . op subop mod rm32 base index scale r32</span> +<span id="L20" class="LineNr">20 </span><span class="subxS1Comment"># . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes</span> +<span id="L21" class="LineNr">21 </span> +<span id="L22" class="LineNr">22 </span><span class="SpecialChar">Entry</span>: +<span id="L23" class="LineNr">23 </span> <span class="subxS1Comment"># . prologue</span> +<span id="L24" class="LineNr">24 </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="L25" class="LineNr">25 </span> <span class="subxComment"># eax = ascii-length(argv[1])</span> +<span id="L26" class="LineNr">26 </span> <span class="subxS2Comment"># . . push args</span> +<span id="L27" class="LineNr">27 </span> ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 8/disp8 <span class="Normal"> . </span> <span class="subxComment"># push *(ebp+8)</span> +<span id="L28" class="LineNr">28 </span> <span class="subxS2Comment"># . . call</span> +<span id="L29" class="LineNr">29 </span> e8/call <a href='ex8.subx.html#L37'>ascii-length</a>/disp32 +<span id="L30" class="LineNr">30 </span> <span class="subxS2Comment"># . . discard args</span> +<span id="L31" class="LineNr">31 </span> 81 0/subop/add 3/mod/direct 4/rm32/esp <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 esp</span> +<span id="L32" class="LineNr">32 </span> +<span id="L33" class="LineNr">33 </span> <span class="subxComment"># exit(eax)</span> +<span id="L34" class="LineNr">34 </span> 89/copy 3/mod/direct 3/rm32/ebx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/eax <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy eax to ebx</span> +<span id="L35" class="LineNr">35 </span> e8/call <a href='000init.subx.html#L18'>syscall_exit</a>/disp32 +<span id="L36" class="LineNr">36 </span> +<span id="L37" class="LineNr">37 </span><span class="subxFunction">ascii-length</span>: <span class="subxComment"># s: (addr array byte) -> n/eax</span> +<span id="L38" class="LineNr">38 </span> <span class="subxComment"># edx = s</span> +<span id="L39" class="LineNr">39 </span> 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/esp 4/index/none <span class="Normal"> . </span> 2/r32/edx 4/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(esp+4) to edx</span> +<span id="L40" class="LineNr">40 </span> <span class="subxComment"># var result/eax = 0</span> +<span id="L41" class="LineNr">41 </span> b8/copy-to-eax 0/imm32 +<span id="L42" class="LineNr">42 </span><span class="Constant">$ascii-length:loop</span>: +<span id="L43" class="LineNr">43 </span> <span class="subxComment"># var c/ecx = *s</span> +<span id="L44" class="LineNr">44 </span> 8a/copy-byte 0/mod/* 2/rm32/edx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 1/r32/CL <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy byte at *edx to CL</span> +<span id="L45" class="LineNr">45 </span> <span class="subxComment"># if (c == '\0') break</span> +<span id="L46" class="LineNr">46 </span> 81 7/subop/compare 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> 0/imm32/null <span class="subxComment"># compare ecx</span> +<span id="L47" class="LineNr">47 </span> 74/jump-if-= $ascii-length:end/disp8 +<span id="L48" class="LineNr">48 </span> <span class="subxComment"># ++s</span> +<span id="L49" class="LineNr">49 </span> 42/increment-edx +<span id="L50" class="LineNr">50 </span> <span class="subxComment"># ++result</span> +<span id="L51" class="LineNr">51 </span> 40/increment-eax +<span id="L52" class="LineNr">52 </span> <span class="subxComment"># loop</span> +<span id="L53" class="LineNr">53 </span> eb/jump $ascii-length:<span class="Constant">loop</span>/disp8 +<span id="L54" class="LineNr">54 </span><span class="Constant">$ascii-length:end</span>: +<span id="L55" class="LineNr">55 </span> <span class="subxComment"># return eax</span> +<span id="L56" class="LineNr">56 </span> c3/return +<span id="L57" class="LineNr">57 </span> +<span id="L58" class="LineNr">58 </span>== data +<span id="L59" class="LineNr">59 </span> +<span id="L60" class="LineNr">60 </span><span class="subxS2Comment"># . . vim:nowrap:textwidth=0</span> +</pre> +</body> +</html> +<!-- vim: set foldmethod=manual : --> |