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Diffstat (limited to 'html/linux/apps/ex12.subx.html')
| -rw-r--r-- | html/linux/apps/ex12.subx.html | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/html/linux/apps/ex12.subx.html b/html/linux/apps/ex12.subx.html new file mode 100644 index 00000000..12b09331 --- /dev/null +++ b/html/linux/apps/ex12.subx.html @@ -0,0 +1,104 @@ +<!DOCTYPE html> +<html> +<head> +<meta charset="UTF-8"> +<title>Mu - linux/apps/ex12.subx</title> +<meta name="Generator" content="Vim/8.2"> +<meta name="plugin-version" content="vim8.1_v2"> +<meta name="syntax" content="none"> +<meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy=,use_input_for_pc=fallback"> +<meta name="colorscheme" content="minimal-light"> +<style> +<!-- +pre { font-family: monospace; color: #000000; background-color: #ffffd7; } +body { font-size:12pt; font-family: monospace; color: #000000; background-color: #ffffd7; } +a { color:inherit; } +* { font-size:12pt; font-size: 1em; } +.subxComment { color: #005faf; } +.subxS2Comment { color: #8a8a8a; } +.LineNr { } +.subxS1Comment { color: #0000af; } +.SpecialChar { color: #d70000; } +.Normal { color: #000000; background-color: #ffffd7; padding-bottom: 1px; } +--> +</style> + +<script> +<!-- + +/* 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/apps/ex12.subx'>https://github.com/akkartik/mu/blob/main/linux/apps/ex12.subx</a> +<pre id='vimCodeElement'> +<span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Example showing mmap syscall.</span> +<span id="L2" class="LineNr"> 2 </span><span class="subxComment"># Create a new segment using mmap, save the address, write to it.</span> +<span id="L3" class="LineNr"> 3 </span><span class="subxComment">#</span> +<span id="L4" class="LineNr"> 4 </span><span class="subxComment"># To run:</span> +<span id="L5" class="LineNr"> 5 </span><span class="subxComment"># $ bootstrap/bootstrap translate apps/ex12.subx -o ex12</span> +<span id="L6" class="LineNr"> 6 </span><span class="subxComment"># $ bootstrap/bootstrap run ex12</span> +<span id="L7" class="LineNr"> 7 </span><span class="subxComment"># You shouldn't get a segmentation fault.</span> +<span id="L8" class="LineNr"> 8 </span> +<span id="L9" class="LineNr"> 9 </span>== code +<span id="L10" class="LineNr">10 </span><span class="subxComment"># instruction effective address register displacement immediate</span> +<span id="L11" class="LineNr">11 </span><span class="subxS1Comment"># . op subop mod rm32 base index scale r32</span> +<span id="L12" class="LineNr">12 </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="L13" class="LineNr">13 </span> +<span id="L14" class="LineNr">14 </span><span class="SpecialChar">Entry</span>: +<span id="L15" class="LineNr">15 </span> <span class="subxComment"># mmap(Mmap-new-segment->len)</span> +<span id="L16" class="LineNr">16 </span> bb/copy-to-ebx <span class="SpecialChar"><a href='ex12.subx.html#L29'>Mmap-new-segment</a></span>/imm32 +<span id="L17" class="LineNr">17 </span> e8/call <a href='../000init.subx.html#L71'>syscall_mmap</a>/disp32 +<span id="L18" class="LineNr">18 </span> +<span id="L19" class="LineNr">19 </span> <span class="subxComment"># write to *eax to check that we have access to the newly-allocated segment</span> +<span id="L20" class="LineNr">20 </span> c7 0/subop/copy 0/mod/direct 0/rm32/eax <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0x34/imm32 <span class="subxComment"># copy to *eax</span> +<span id="L21" class="LineNr">21 </span> +<span id="L22" class="LineNr">22 </span> <span class="subxComment"># exit(eax)</span> +<span id="L23" class="LineNr">23 </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="L24" class="LineNr">24 </span> e8/call <a href='../000init.subx.html#L18'>syscall_exit</a>/disp32 +<span id="L25" class="LineNr">25 </span> +<span id="L26" class="LineNr">26 </span>== data +<span id="L27" class="LineNr">27 </span> +<span id="L28" class="LineNr">28 </span><span class="subxComment"># various constants used here were found in the Linux sources (search for file mman-common.h)</span> +<span id="L29" class="LineNr">29 </span><span class="SpecialChar">Mmap-new-segment</span>: <span class="subxComment"># type mmap_arg_struct</span> +<span id="L30" class="LineNr">30 </span> <span class="subxComment"># addr</span> +<span id="L31" class="LineNr">31 </span> 0/imm32 +<span id="L32" class="LineNr">32 </span> <span class="subxComment"># len</span> +<span id="L33" class="LineNr">33 </span> 0x100/imm32 +<span id="L34" class="LineNr">34 </span> <span class="subxComment"># protection flags</span> +<span id="L35" class="LineNr">35 </span> 3/imm32 <span class="subxComment"># PROT_READ | PROT_WRITE</span> +<span id="L36" class="LineNr">36 </span> <span class="subxComment"># sharing flags</span> +<span id="L37" class="LineNr">37 </span> 0x22/imm32 <span class="subxComment"># MAP_PRIVATE | MAP_ANONYMOUS</span> +<span id="L38" class="LineNr">38 </span> <span class="subxComment"># fd</span> +<span id="L39" class="LineNr">39 </span> -1/imm32 <span class="subxComment"># since MAP_ANONYMOUS is specified</span> +<span id="L40" class="LineNr">40 </span> <span class="subxComment"># offset</span> +<span id="L41" class="LineNr">41 </span> 0/imm32 <span class="subxComment"># since MAP_ANONYMOUS is specified</span> +<span id="L42" class="LineNr">42 </span> +<span id="L43" class="LineNr">43 </span><span class="subxS2Comment"># . . vim:nowrap:textwidth=0</span> +</pre> +</body> +</html> +<!-- vim: set foldmethod=manual : --> |