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<a href='https://github.com/akkartik/mu/blob/main/linux/random.subx'>https://github.com/akkartik/mu/blob/main/linux/random.subx</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Repeatedly read 32-bit numbers from /dev/random, print them to stdout.</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 [01]*.subx random.subx -o random</span>
<span id="L5" class="LineNr"> 5 </span><span class="subxComment"># $ bootstrap/bootstrap run random</span>
<span id="L6" class="LineNr"> 6 </span>
<span id="L7" class="LineNr"> 7 </span>== code 0x09000000
<span id="L8" class="LineNr"> 8 </span><span class="subxComment"># instruction effective address register displacement immediate</span>
<span id="L9" class="LineNr"> 9 </span><span class="subxS1Comment"># . op subop mod rm32 base index scale r32</span>
<span id="L10" class="LineNr">10 </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="L11" class="LineNr">11 </span>
<span id="L12" class="LineNr">12 </span><span class="SpecialChar">Entry</span>:
<span id="L13" class="LineNr">13 </span> <span class="subxComment"># stream/esi = syscall(open, "/dev/null", O_RDONLY, 0) # we can't use 'fd' because it looks like a hex byte</span>
<span id="L14" class="LineNr">14 </span> bb/copy-to-ebx <span class="SpecialChar"><a href='random.subx.html#L55'>Filename</a></span>/imm32
<span id="L15" class="LineNr">15 </span> b9/copy-to-ecx 0/imm32/rdonly
<span id="L16" class="LineNr">16 </span> ba/copy-to-edx 0x180/imm32/fixed-perms
<span id="L17" class="LineNr">17 </span> e8/call <a href='000init.subx.html#L35'>syscall_open</a>/disp32
<span id="L18" class="LineNr">18 </span> <span class="subxS1Comment"># . stream = eax</span>
<span id="L19" class="LineNr">19 </span> 89/copy 3/mod/direct 6/rm32/esi <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 esi</span>
<span id="L20" class="LineNr">20 </span>
<span id="L21" class="LineNr">21 </span><span class="Constant">$loop</span>:
<span id="L22" class="LineNr">22 </span>
<span id="L23" class="LineNr">23 </span> <span class="subxComment"># syscall(read, Stream, N, 4)</span>
<span id="L24" class="LineNr">24 </span> 89/copy 3/mod/direct 3/rm32/ebx <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 6/r32/esi <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy esi to ebx</span>
<span id="L25" class="LineNr">25 </span> b9/copy-to-ecx <span class="SpecialChar"><a href='random.subx.html#L53'>N</a></span>/imm32
<span id="L26" class="LineNr">26 </span> ba/copy-to-edx 4/imm32/size
<span id="L27" class="LineNr">27 </span> e8/call <a href='000init.subx.html#L23'>syscall_read</a>/disp32
<span id="L28" class="LineNr">28 </span>
<span id="L29" class="LineNr">29 </span> <span class="subxComment"># write-int32-hex-buffered(Stdout, *N)</span>
<span id="L30" class="LineNr">30 </span> <span class="subxS2Comment"># . . push args</span>
<span id="L31" class="LineNr">31 </span> ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="SpecialChar"><a href='random.subx.html#L53'>N</a></span>/disp32 <span class="subxComment"># push *N</span>
<span id="L32" class="LineNr">32 </span> 68/push <span class="SpecialChar"><a href='115write-byte.subx.html#L10'>Stdout</a></span>/imm32
<span id="L33" class="LineNr">33 </span> <span class="subxS2Comment"># . . call</span>
<span id="L34" class="LineNr">34 </span> e8/call <a href='117write-int-hex.subx.html#L288'>write-int32-hex-buffered</a>/disp32
<span id="L35" class="LineNr">35 </span>
<span id="L36" class="LineNr">36 </span> <span class="subxComment"># write-buffered(Stdout, Newline)</span>
<span id="L37" class="LineNr">37 </span> <span class="subxS2Comment"># . . push args</span>
<span id="L38" class="LineNr">38 </span> 68/push <span class="SpecialChar"><a href='102test.subx.html#L82'>Newline</a></span>/imm32
<span id="L39" class="LineNr">39 </span> 68/push <span class="SpecialChar"><a href='115write-byte.subx.html#L10'>Stdout</a></span>/imm32
<span id="L40" class="LineNr">40 </span> <span class="subxS2Comment"># . . call</span>
<span id="L41" class="LineNr">41 </span> e8/call <a href='116write-buffered.subx.html#L8'>write-buffered</a>/disp32
<span id="L42" class="LineNr">42 </span> <span class="subxS2Comment"># . . discard args</span>
<span id="L43" class="LineNr">43 </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> 8/imm32 <span class="subxComment"># add to esp</span>
<span id="L44" class="LineNr">44 </span>
<span id="L45" class="LineNr">45 </span> eb/jump $loop/disp8
<span id="L46" class="LineNr">46 </span>
<span id="L47" class="LineNr">47 </span> <span class="subxComment"># syscall(exit, 0)</span>
<span id="L48" class="LineNr">48 </span> bb/copy-to-ebx 0/imm32
<span id="L49" class="LineNr">49 </span> e8/call <a href='000init.subx.html#L18'>syscall_exit</a>/disp32
<span id="L50" class="LineNr">50 </span>
<span id="L51" class="LineNr">51 </span>== data 0x0a000000
<span id="L52" class="LineNr">52 </span>
<span id="L53" class="LineNr">53 </span><span class="SpecialChar">N</span>:
<span id="L54" class="LineNr">54 </span> 0/imm32
<span id="L55" class="LineNr">55 </span><span class="SpecialChar">Filename</span>:
<span id="L56" class="LineNr">56 </span> 2f 64 65 76 2f 72 61 6e 64 6f 6d 00
<span id="L57" class="LineNr">57 </span><span class="subxComment"># / d e v / r a n d o m null</span>
<span id="L58" class="LineNr">58 </span>
<span id="L59" class="LineNr">59 </span><span class="subxS2Comment"># . . vim:nowrap:textwidth=0</span>
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