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author | Kartik Agaram <vc@akkartik.com> | 2021-04-13 21:11:26 -0700 |
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committer | Kartik Agaram <vc@akkartik.com> | 2021-04-13 21:11:26 -0700 |
commit | 5a3f9a31850d6da72dff7211c9760cd4a8e1090b (patch) | |
tree | da45bfbfa58a4573b6c1898006dfaf146352eb40 /html/102keyboard.subx.html | |
parent | fea45ccbea6bee563b41da199fb3c456c6069cb5 (diff) | |
download | mu-5a3f9a31850d6da72dff7211c9760cd4a8e1090b.tar.gz |
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Diffstat (limited to 'html/102keyboard.subx.html')
-rw-r--r-- | html/102keyboard.subx.html | 90 |
1 files changed, 51 insertions, 39 deletions
diff --git a/html/102keyboard.subx.html b/html/102keyboard.subx.html index b8f9a64b..2d711074 100644 --- a/html/102keyboard.subx.html +++ b/html/102keyboard.subx.html @@ -63,45 +63,57 @@ if ('onhashchange' in window) { <span id="L6" class="LineNr"> 6 </span> <span id="L7" class="LineNr"> 7 </span>== code <span id="L8" class="LineNr"> 8 </span> -<span id="L9" class="LineNr"> 9 </span><span class="subxFunction">read-key</span>: <span class="subxComment"># kbd: (addr keyboard) -> result/eax: byte</span> -<span id="L10" class="LineNr">10 </span> <span class="subxS1Comment"># . prologue</span> -<span id="L11" class="LineNr">11 </span> 55/push-ebp -<span id="L12" class="LineNr">12 </span> 89/<- %ebp 4/r32/esp -<span id="L13" class="LineNr">13 </span> <span class="subxS1Comment"># . save registers</span> -<span id="L14" class="LineNr">14 </span> 51/push-ecx -<span id="L15" class="LineNr">15 </span> <span class="subxComment"># result = 0</span> -<span id="L16" class="LineNr">16 </span> b8/copy-to-eax 0/imm32 -<span id="L17" class="LineNr">17 </span> <span class="subxComment"># ecx = keyboard</span> -<span id="L18" class="LineNr">18 </span> 8b/-> *(ebp+8) 1/r32/ecx -<span id="L19" class="LineNr">19 </span> 81 7/subop/compare %ecx 0/imm32 -<span id="L20" class="LineNr">20 </span> { -<span id="L21" class="LineNr">21 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 -<span id="L22" class="LineNr">22 </span> <span class="subxComment"># var buffer-byte-addr/ecx: (addr byte)</span> -<span id="L23" class="LineNr">23 </span> 8b/-> *<span class="SpecialChar">Keyboard-buffer</span>:read 1/r32/CL -<span id="L24" class="LineNr">24 </span> 81 0/subop/add %ecx <span class="SpecialChar">Keyboard-buffer</span>:data/imm32 -<span id="L25" class="LineNr">25 </span> <span class="subxComment"># var next-key/eax: byte = *buffer-byte-addr</span> -<span id="L26" class="LineNr">26 </span> 8a/byte-> *ecx 0/r32/AL -<span id="L27" class="LineNr">27 </span> <span class="subxComment"># if (next-key != 0) lock and remove from keyboard buffer</span> -<span id="L28" class="LineNr">28 </span> 81 7/subop/compare %eax 0/imm32 -<span id="L29" class="LineNr">29 </span> { -<span id="L30" class="LineNr">30 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 -<span id="L31" class="LineNr">31 </span> fa/disable-interrupts -<span id="L32" class="LineNr">32 </span> c6 0/subop/copy-byte *ecx 0/imm8 -<span id="L33" class="LineNr">33 </span> ff 0/subop/increment *<span class="SpecialChar">Keyboard-buffer</span>:read -<span id="L34" class="LineNr">34 </span> 81 4/subop/and *<span class="SpecialChar">Keyboard-buffer</span>:read 0x0f/imm32 -<span id="L35" class="LineNr">35 </span> fb/enable-interrupts -<span id="L36" class="LineNr">36 </span> } -<span id="L37" class="LineNr">37 </span> <span class="subxComment"># return</span> -<span id="L38" class="LineNr">38 </span> eb $read-key:end/disp8 -<span id="L39" class="LineNr">39 </span> } -<span id="L40" class="LineNr">40 </span> <span class="subxComment"># TODO: fake keyboard</span> -<span id="L41" class="LineNr">41 </span><span class="Constant">$read-key: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> <span class="subxS1Comment"># . epilogue</span> -<span id="L45" class="LineNr">45 </span> 89/<- %esp 5/r32/ebp -<span id="L46" class="LineNr">46 </span> 5d/pop-to-ebp -<span id="L47" class="LineNr">47 </span> c3/return +<span id="L9" class="LineNr"> 9 </span><span class="subxComment"># Most keys correspond to their ASCII/Unicode values.</span> +<span id="L10" class="LineNr">10 </span><span class="subxComment"># TODO: Support for international keyboards and multi-byte Unicode.</span> +<span id="L11" class="LineNr">11 </span><span class="subxComment">#</span> +<span id="L12" class="LineNr">12 </span><span class="subxComment"># However there are some exceptions that have no assigned place in Unicode</span> +<span id="L13" class="LineNr">13 </span><span class="subxComment"># (and with good reason):</span> +<span id="L14" class="LineNr">14 </span><span class="subxComment"># 0x80 = left arrow ←</span> +<span id="L15" class="LineNr">15 </span><span class="subxComment"># 0x81 = down arrow ↓</span> +<span id="L16" class="LineNr">16 </span><span class="subxComment"># 0x82 = up arrow ↑</span> +<span id="L17" class="LineNr">17 </span><span class="subxComment"># 0x83 = right arrow →</span> +<span id="L18" class="LineNr">18 </span><span class="subxComment"># These code points are not used by Unicode and their semantics are agreed to</span> +<span id="L19" class="LineNr">19 </span><span class="subxComment"># be context-sensitive: <a href="https://en.wikipedia.org/wiki/C0_and_C1_control_codes#C1_controls.">https://en.wikipedia.org/wiki/C0_and_C1_control_codes#C1_controls.</a></span> +<span id="L20" class="LineNr">20 </span><span class="subxComment"># Mu cannibalizes them in yet another non-standard way.</span> +<span id="L21" class="LineNr">21 </span><span class="subxFunction">read-key</span>: <span class="subxComment"># kbd: (addr keyboard) -> result/eax: byte</span> +<span id="L22" class="LineNr">22 </span> <span class="subxS1Comment"># . prologue</span> +<span id="L23" class="LineNr">23 </span> 55/push-ebp +<span id="L24" class="LineNr">24 </span> 89/<- %ebp 4/r32/esp +<span id="L25" class="LineNr">25 </span> <span class="subxS1Comment"># . save registers</span> +<span id="L26" class="LineNr">26 </span> 51/push-ecx +<span id="L27" class="LineNr">27 </span> <span class="subxComment"># result = 0</span> +<span id="L28" class="LineNr">28 </span> b8/copy-to-eax 0/imm32 +<span id="L29" class="LineNr">29 </span> <span class="subxComment"># ecx = keyboard</span> +<span id="L30" class="LineNr">30 </span> 8b/-> *(ebp+8) 1/r32/ecx +<span id="L31" class="LineNr">31 </span> 81 7/subop/compare %ecx 0/imm32 +<span id="L32" class="LineNr">32 </span> { +<span id="L33" class="LineNr">33 </span> 75/jump-if-!= <span class="Constant">break</span>/disp8 +<span id="L34" class="LineNr">34 </span> <span class="subxComment"># var buffer-byte-addr/ecx: (addr byte)</span> +<span id="L35" class="LineNr">35 </span> 8b/-> *<span class="SpecialChar">Keyboard-buffer</span>:read 1/r32/CL +<span id="L36" class="LineNr">36 </span> 81 0/subop/add %ecx <span class="SpecialChar">Keyboard-buffer</span>:data/imm32 +<span id="L37" class="LineNr">37 </span> <span class="subxComment"># var next-key/eax: byte = *buffer-byte-addr</span> +<span id="L38" class="LineNr">38 </span> 8a/byte-> *ecx 0/r32/AL +<span id="L39" class="LineNr">39 </span> <span class="subxComment"># if (next-key != 0) lock and remove from keyboard buffer</span> +<span id="L40" class="LineNr">40 </span> 81 7/subop/compare %eax 0/imm32 +<span id="L41" class="LineNr">41 </span> { +<span id="L42" class="LineNr">42 </span> 74/jump-if-= <span class="Constant">break</span>/disp8 +<span id="L43" class="LineNr">43 </span> fa/disable-interrupts +<span id="L44" class="LineNr">44 </span> c6 0/subop/copy-byte *ecx 0/imm8 +<span id="L45" class="LineNr">45 </span> ff 0/subop/increment *<span class="SpecialChar">Keyboard-buffer</span>:read +<span id="L46" class="LineNr">46 </span> 81 4/subop/and *<span class="SpecialChar">Keyboard-buffer</span>:read 0x0f/imm32 +<span id="L47" class="LineNr">47 </span> fb/enable-interrupts +<span id="L48" class="LineNr">48 </span> } +<span id="L49" class="LineNr">49 </span> <span class="subxComment"># return</span> +<span id="L50" class="LineNr">50 </span> eb $read-key:end/disp8 +<span id="L51" class="LineNr">51 </span> } +<span id="L52" class="LineNr">52 </span> <span class="subxComment"># TODO: fake keyboard</span> +<span id="L53" class="LineNr">53 </span><span class="Constant">$read-key:end</span>: +<span id="L54" class="LineNr">54 </span> <span class="subxS1Comment"># . restore registers</span> +<span id="L55" class="LineNr">55 </span> 59/pop-to-ecx +<span id="L56" class="LineNr">56 </span> <span class="subxS1Comment"># . epilogue</span> +<span id="L57" class="LineNr">57 </span> 89/<- %esp 5/r32/ebp +<span id="L58" class="LineNr">58 </span> 5d/pop-to-ebp +<span id="L59" class="LineNr">59 </span> c3/return </pre> </body> </html> |