7549

1 files changed, 41 insertions, 47 deletions

diff --git a/html/baremetal/101screen.subx.html b/html/baremetal/101screen.subx.html
index 1f204a59..b41c8b85 100644
--- a/html/baremetal/101screen.subx.html
+++ b/html/baremetal/101screen.subx.html
@@ -55,53 +55,47 @@ if ('onhashchange' in window) {
 <a href='https://github.com/akkartik/mu/blob/main/baremetal/101screen.subx'>https://github.com/akkartik/mu/blob/main/baremetal/101screen.subx</a>
 <pre id='vimCodeElement'>
 <span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Primitives for screen control.</span>
-<span id="L2" class="LineNr"> 2 </span>
-<span id="L3" class="LineNr"> 3 </span>== code
-<span id="L4" class="LineNr"> 4 </span>
-<span id="L5" class="LineNr"> 5 </span><span class="subxFunction">pixel</span>:  <span class="subxComment"># screen: (addr screen), x: int, y: int, color: int</span>
-<span id="L6" class="LineNr"> 6 </span>    <span class="subxS1Comment"># . prologue</span>
-<span id="L7" class="LineNr"> 7 </span>    55/push-ebp
-<span id="L8" class="LineNr"> 8 </span>    89/&lt;- %ebp 4/r32/esp
-<span id="L9" class="LineNr"> 9 </span>    <span class="subxS1Comment"># . save registers</span>
-<span id="L10" class="LineNr">10 </span>    50/push-eax
-<span id="L11" class="LineNr">11 </span>    51/push-ecx
-<span id="L12" class="LineNr">12 </span>    <span class="subxComment"># ecx = screen</span>
-<span id="L13" class="LineNr">13 </span>    8b/-&gt; *(ebp+8) 1/r32/ecx
-<span id="L14" class="LineNr">14 </span>    81 7/subop/compare %ecx 0/imm32
-<span id="L15" class="LineNr">15 </span>    {
-<span id="L16" class="LineNr">16 </span>      75/jump-if-!= <span class="Constant">break</span>/disp8
-<span id="L17" class="LineNr">17 </span>      <span class="subxComment"># bounds checks</span>
-<span id="L18" class="LineNr">18 </span>      8b/-&gt; *(ebp+0xc) 0/r32/eax
-<span id="L19" class="LineNr">19 </span>      3d/compare-eax-and 0/imm32
-<span id="L20" class="LineNr">20 </span>      7c/jump-if-&lt; $pixel:end/disp8
-<span id="L21" class="LineNr">21 </span>      3d/compare-eax-and 0x400/imm32/1024
-<span id="L22" class="LineNr">22 </span>      7d/jump-if-&gt;= $pixel:end/disp8
-<span id="L23" class="LineNr">23 </span>      8b/-&gt; *(ebp+0x10) 0/r32/eax
-<span id="L24" class="LineNr">24 </span>      3d/compare-eax-and 0/imm32
-<span id="L25" class="LineNr">25 </span>      7c/jump-if-&lt; $pixel:end/disp8
-<span id="L26" class="LineNr">26 </span>      3d/compare-eax-and 0x300/imm32/768
-<span id="L27" class="LineNr">27 </span>      7d/jump-if-&gt;= $pixel:end/disp8
-<span id="L28" class="LineNr">28 </span>      <span class="subxComment"># eax = y*1024 + x</span>
-<span id="L29" class="LineNr">29 </span>      8b/-&gt; *(ebp+0x10) 0/r32/eax
-<span id="L30" class="LineNr">30 </span>      c1/shift 4/subop/left %eax 0xa/imm8
-<span id="L31" class="LineNr">31 </span>      03/add-&gt; *(ebp+0xc) 0/r32/eax
-<span id="L32" class="LineNr">32 </span>      <span class="subxComment"># eax += location of frame buffer</span>
-<span id="L33" class="LineNr">33 </span>      03/add-&gt; *0x7f28 0/r32/eax
-<span id="L34" class="LineNr">34 </span>      <span class="subxComment"># *eax = color</span>
-<span id="L35" class="LineNr">35 </span>      8b/-&gt; *(ebp+0x14) 1/r32/ecx
-<span id="L36" class="LineNr">36 </span>      88/byte&lt;- *eax 1/r32/CL
-<span id="L37" class="LineNr">37 </span>      <span class="subxComment"># return</span>
-<span id="L38" class="LineNr">38 </span>      eb $pixel:end/disp8
-<span id="L39" class="LineNr">39 </span>    }
-<span id="L40" class="LineNr">40 </span>    <span class="subxComment"># TODO: fake screen</span>
-<span id="L41" class="LineNr">41 </span><span class="Constant">$pixel:end</span>:
-<span id="L42" class="LineNr">42 </span>    <span class="subxS1Comment"># . restore registers</span>
-<span id="L43" class="LineNr">43 </span>    59/pop-to-ecx
-<span id="L44" class="LineNr">44 </span>    58/pop-to-eax
-<span id="L45" class="LineNr">45 </span>    <span class="subxS1Comment"># . epilogue</span>
-<span id="L46" class="LineNr">46 </span>    89/&lt;- %esp 5/r32/ebp
-<span id="L47" class="LineNr">47 </span>    5d/pop-to-ebp
-<span id="L48" class="LineNr">48 </span>    c3/return
+<span id="L2" class="LineNr"> 2 </span><span class="subxComment">#</span>
+<span id="L3" class="LineNr"> 3 </span><span class="subxComment"># We need to do this in machine code because Mu doesn't have global variables</span>
+<span id="L4" class="LineNr"> 4 </span><span class="subxComment"># yet (for the start of video memory).</span>
+<span id="L5" class="LineNr"> 5 </span>
+<span id="L6" class="LineNr"> 6 </span>== code
+<span id="L7" class="LineNr"> 7 </span>
+<span id="L8" class="LineNr"> 8 </span><span class="subxFunction">pixel-on-real-screen</span>:  <span class="subxComment"># x: int, y: int, color: int</span>
+<span id="L9" class="LineNr"> 9 </span>    <span class="subxS1Comment"># . prologue</span>
+<span id="L10" class="LineNr">10 </span>    55/push-ebp
+<span id="L11" class="LineNr">11 </span>    89/&lt;- %ebp 4/r32/esp
+<span id="L12" class="LineNr">12 </span>    <span class="subxS1Comment"># . save registers</span>
+<span id="L13" class="LineNr">13 </span>    50/push-eax
+<span id="L14" class="LineNr">14 </span>    51/push-ecx
+<span id="L15" class="LineNr">15 </span>    <span class="subxComment"># bounds checks</span>
+<span id="L16" class="LineNr">16 </span>    8b/-&gt; *(ebp+8) 0/r32/eax
+<span id="L17" class="LineNr">17 </span>    3d/compare-eax-and 0/imm32
+<span id="L18" class="LineNr">18 </span>    7c/jump-if-&lt; $pixel-on-real-screen:end/disp8
+<span id="L19" class="LineNr">19 </span>    3d/compare-eax-and 0x400/imm32/screen-width=1024
+<span id="L20" class="LineNr">20 </span>    7d/jump-if-&gt;= $pixel-on-real-screen:end/disp8
+<span id="L21" class="LineNr">21 </span>    8b/-&gt; *(ebp+0xc) 0/r32/eax
+<span id="L22" class="LineNr">22 </span>    3d/compare-eax-and 0/imm32
+<span id="L23" class="LineNr">23 </span>    7c/jump-if-&lt; $pixel-on-real-screen:end/disp8
+<span id="L24" class="LineNr">24 </span>    3d/compare-eax-and 0x300/imm32/screen-height=768
+<span id="L25" class="LineNr">25 </span>    7d/jump-if-&gt;= $pixel-on-real-screen:end/disp8
+<span id="L26" class="LineNr">26 </span>    <span class="subxComment"># eax = y*1024 + x</span>
+<span id="L27" class="LineNr">27 </span>    8b/-&gt; *(ebp+0xc) 0/r32/eax
+<span id="L28" class="LineNr">28 </span>    c1/shift 4/subop/left %eax 0xa/imm8
+<span id="L29" class="LineNr">29 </span>    03/add-&gt; *(ebp+8) 0/r32/eax
+<span id="L30" class="LineNr">30 </span>    <span class="subxComment"># eax += location of frame buffer</span>
+<span id="L31" class="LineNr">31 </span>    03/add-&gt; *0x7f28 0/r32/eax  <span class="subxComment"># unsafe</span>
+<span id="L32" class="LineNr">32 </span>    <span class="subxComment"># *eax = color</span>
+<span id="L33" class="LineNr">33 </span>    8b/-&gt; *(ebp+0x10) 1/r32/ecx
+<span id="L34" class="LineNr">34 </span>    88/byte&lt;- *eax 1/r32/CL
+<span id="L35" class="LineNr">35 </span><span class="Constant">$pixel-on-real-screen:end</span>:
+<span id="L36" class="LineNr">36 </span>    <span class="subxS1Comment"># . restore registers</span>
+<span id="L37" class="LineNr">37 </span>    59/pop-to-ecx
+<span id="L38" class="LineNr">38 </span>    58/pop-to-eax
+<span id="L39" class="LineNr">39 </span>    <span class="subxS1Comment"># . epilogue</span>
+<span id="L40" class="LineNr">40 </span>    89/&lt;- %esp 5/r32/ebp
+<span id="L41" class="LineNr">41 </span>    5d/pop-to-ebp
+<span id="L42" class="LineNr">42 </span>    c3/return
 </pre>
 </body>
 </html>