2021-03-24 00:31:08 +00:00
<!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 - boot.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,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=" >
< meta name = "colorscheme" content = "minimal-light" >
< style type = "text/css" >
<!--
pre { white-space: pre-wrap; 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; }
.subxH1Comment { color: #005faf; text-decoration: underline; }
.subxComment { color: #005faf; }
.subxFunction { color: #af5f00; text-decoration: underline; }
.LineNr { }
.SpecialChar { color: #d70000; }
.Constant { color: #008787; }
.Folded { color: #080808; background-color: #949494; }
.subxS1Comment { color: #0000af; }
-->
< / 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/boot.subx' > https://github.com/akkartik/mu/blob/main/boot.subx< / a >
< pre id = 'vimCodeElement' >
< span id = "L1" class = "LineNr" > 1 < / span > < span class = "subxComment" > # Code for the first few disk sectors that all programs in this directory need:< / span >
< span id = "L2" class = "LineNr" > 2 < / span > < span class = "subxComment" > # - load sectors past the first (using BIOS primitives) since only the first is available by default< / span >
< span id = "L3" class = "LineNr" > 3 < / span > < span class = "subxComment" > # - if this fails, print 'D' at top-left of screen and halt< / span >
< span id = "L4" class = "LineNr" > 4 < / span > < span class = "subxComment" > # - initialize a minimal graphics mode< / span >
< span id = "L5" class = "LineNr" > 5 < / span > < span class = "subxComment" > # - switch to 32-bit mode (giving up access to BIOS primitives)< / span >
< span id = "L6" class = "LineNr" > 6 < / span > < span class = "subxComment" > # - set up a handler for keyboard events< / span >
< span id = "L7" class = "LineNr" > 7 < / span > < span class = "subxComment" > # - jump to start of program< / span >
< span id = "L8" class = "LineNr" > 8 < / span >
< span id = "L9" class = "LineNr" > 9 < / span > < span class = "subxComment" > # Code in this file needs to be more deliberate about the SubX facilities it< / span >
< span id = "L10" class = "LineNr" > 10 < / span > < span class = "subxComment" > # uses:< / span >
< span id = "L11" class = "LineNr" > 11 < / span > < span class = "subxComment" > # - sigils only support 32-bit general-purpose registers, so don't work with segment registers or 16-bit or 8-bit registers< / span >
< span id = "L12" class = "LineNr" > 12 < / span > < span class = "subxComment" > # - metadata like rm32 and r32 can sometimes misleadingly refer to only the bottom 16 bits of the register; pay attention to the register name< / span >
2021-03-24 05:27:46 +00:00
< span id = "L13" class = "LineNr" > 13 < / span > < span class = "subxComment" > #< / span >
< span id = "L14" class = "LineNr" > 14 < / span > < span class = "subxComment" > # While most of Mu is thoroughly tested, this file is not. I don't yet< / span >
< span id = "L15" class = "LineNr" > 15 < / span > < span class = "subxComment" > # understand hardware interfaces well enough to explain to others.< / span >
< span id = "L16" class = "LineNr" > 16 < / span >
< span id = "L17" class = "LineNr" > 17 < / span > < span class = "subxComment" > # Memory map of a Mu computer:< / span >
< span id = "L18" class = "LineNr" > 18 < / span > < span class = "subxComment" > # code: currently 4 tracks loaded from the primary disk to [0x00007c00, 0x00027400)< / span >
< span id = "L19" class = "LineNr" > 19 < / span > < span class = "subxComment" > # stack: grows down from 0x00070000< / span >
< span id = "L20" class = "LineNr" > 20 < / span > < span class = "subxComment" > # heap: [0x01000000, 0x02000000)< / span >
< span id = "L21" class = "LineNr" > 21 < / span > < span class = "subxComment" > # see 120allocate.subx< / span >
< span id = "L22" class = "LineNr" > 22 < / span > < span class = "subxComment" > # Consult < a href = "https://wiki.osdev.org/Memory_Map_(x86)" > https://wiki.osdev.org/Memory_Map_(x86)< / a > before modifying any of this.< / span >
2021-03-24 00:31:08 +00:00
< span id = "L23" class = "LineNr" > 23 < / span >
2021-03-24 05:27:46 +00:00
< span id = "L24" class = "LineNr" > 24 < / span > == code
2021-03-24 00:31:08 +00:00
< span id = "L25" class = "LineNr" > 25 < / span >
2021-03-24 05:27:46 +00:00
< span id = "L26" class = "LineNr" > 26 < / span > < span class = "subxComment" > ## 16-bit entry point: 0x7c00< / span >
< span id = "L27" class = "LineNr" > 27 < / span >
< span id = "L28" class = "LineNr" > 28 < / span > < span class = "subxComment" > # Upon reset, the IBM PC:< / span >
< span id = "L29" class = "LineNr" > 29 < / span > < span class = "subxComment" > # - loads the first sector (512 bytes)< / span >
< span id = "L30" class = "LineNr" > 30 < / span > < span class = "subxComment" > # from some bootable image (look for the boot-sector-marker further down this file)< / span >
< span id = "L31" class = "LineNr" > 31 < / span > < span class = "subxComment" > # to the address range [0x7c00, 0x7e00)< / span >
< span id = "L32" class = "LineNr" > 32 < / span > < span class = "subxComment" > # - starts executing code at address 0x7c00< / span >
2021-03-24 00:31:08 +00:00
< span id = "L33" class = "LineNr" > 33 < / span >
2021-03-24 05:27:46 +00:00
< span id = "L34" class = "LineNr" > 34 < / span > fa/disable-interrupts
< span id = "L35" class = "LineNr" > 35 < / span >
< span id = "L36" class = "LineNr" > 36 < / span > < span class = "subxComment" > # initialize segment registers< / span >
< span id = "L37" class = "LineNr" > 37 < / span > b8/copy-to-ax 0/imm16
< span id = "L38" class = "LineNr" > 38 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 3/r32/ds
< span id = "L39" class = "LineNr" > 39 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 0/r32/es
< span id = "L40" class = "LineNr" > 40 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 4/r32/fs
< span id = "L41" class = "LineNr" > 41 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 5/r32/gs
< span id = "L42" class = "LineNr" > 42 < / span >
< span id = "L43" class = "LineNr" > 43 < / span > < span class = "subxComment" > # initialize stack to 0x00070000< / span >
< span id = "L44" class = "LineNr" > 44 < / span > < span class = "subxComment" > # We don't read or write the stack before we get to 32-bit mode, but BIOS< / span >
< span id = "L45" class = "LineNr" > 45 < / span > < span class = "subxComment" > # calls do. We need to move the stack in case BIOS initializes it to some< / span >
< span id = "L46" class = "LineNr" > 46 < / span > < span class = "subxComment" > # low address that we want to write code into.< / span >
< span id = "L47" class = "LineNr" > 47 < / span > b8/copy-to-ax 0x7000/imm16
< span id = "L48" class = "LineNr" > 48 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 2/r32/ss
< span id = "L49" class = "LineNr" > 49 < / span > bc/copy-to-esp 0/imm16
< span id = "L50" class = "LineNr" > 50 < / span >
< span id = "L51" class = "LineNr" > 51 < / span > < span class = "subxComment" > # undo the A20 hack: < a href = "https://en.wikipedia.org/wiki/A20_line" > https://en.wikipedia.org/wiki/A20_line< / a > < / span >
< span id = "L52" class = "LineNr" > 52 < / span > < span class = "subxComment" > # this is from < a href = "https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S" > https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S< / a > < / span >
< span id = "L53" class = "LineNr" > 53 < / span > {
< span id = "L54" class = "LineNr" > 54 < / span > e4/read-port-into-al 0x64/imm8
< span id = "L55" class = "LineNr" > 55 < / span > a8/test-bits-in-al 0x02/imm8 < span class = "subxComment" > # set zf if bit 1 (second-least significant) is not set< / span >
< span id = "L56" class = "LineNr" > 56 < / span > 75/jump-if-!zero < span class = "Constant" > loop< / span > /imm8
< span id = "L57" class = "LineNr" > 57 < / span > b0/copy-to-al 0xd1/imm8
< span id = "L58" class = "LineNr" > 58 < / span > e6/write-al-into-port 0x64/imm8
< span id = "L59" class = "LineNr" > 59 < / span > }
< span id = "L60" class = "LineNr" > 60 < / span > {
< span id = "L61" class = "LineNr" > 61 < / span > e4/read-port-into-al 0x64/imm8
< span id = "L62" class = "LineNr" > 62 < / span > a8/test-bits-in-al 0x02/imm8 < span class = "subxComment" > # set zf if bit 1 (second-least significant) is not set< / span >
< span id = "L63" class = "LineNr" > 63 < / span > 75/jump-if-!zero < span class = "Constant" > loop< / span > /imm8
< span id = "L64" class = "LineNr" > 64 < / span > b0/copy-to-al 0xdf/imm8
< span id = "L65" class = "LineNr" > 65 < / span > e6/write-al-into-port 0x64/imm8
< span id = "L66" class = "LineNr" > 66 < / span > }
< span id = "L67" class = "LineNr" > 67 < / span >
< span id = "L68" class = "LineNr" > 68 < / span > < span class = "subxComment" > # load remaining sectors from first two tracks of disk into addresses [0x7e00, 0x17800)< / span >
< span id = "L69" class = "LineNr" > 69 < / span > b4/copy-to-ah 2/imm8/read-drive
< span id = "L70" class = "LineNr" > 70 < / span > < span class = "subxComment" > # dl comes conveniently initialized at boot time with the index of the device being booted< / span >
< span id = "L71" class = "LineNr" > 71 < / span > b5/copy-to-ch 0/imm8/cylinder
< span id = "L72" class = "LineNr" > 72 < / span > b6/copy-to-dh 0/imm8/head
< span id = "L73" class = "LineNr" > 73 < / span > b1/copy-to-cl 2/imm8/sector < span class = "subxComment" > # 1-based< / span >
< span id = "L74" class = "LineNr" > 74 < / span > b0/copy-to-al 0x7d/imm8/num-sectors < span class = "subxComment" > # 2*63 - 1 = 125< / span >
< span id = "L75" class = "LineNr" > 75 < / span > < span class = "subxComment" > # address to write sectors to = es:bx = 0x7e00, contiguous with boot segment< / span >
< span id = "L76" class = "LineNr" > 76 < / span > bb/copy-to-bx 0/imm16
< span id = "L77" class = "LineNr" > 77 < / span > 8e/-> seg 3/mod/direct 3/rm32/bx 0/r32/es
< span id = "L78" class = "LineNr" > 78 < / span > bb/copy-to-bx 0x7e00/imm16
< span id = "L79" class = "LineNr" > 79 < / span > cd/syscall 0x13/imm8/bios-disk-services
< span id = "L80" class = "LineNr" > 80 < / span > 0f 82/jump-if-carry < a href = 'boot.subx.html#L146' > disk_error< / a > /disp16
< span id = "L81" class = "LineNr" > 81 < / span >
< span id = "L82" class = "LineNr" > 82 < / span > < span class = "subxComment" > # load two more tracks of disk into addresses [0x17800, 0x27400)< / span >
< span id = "L83" class = "LineNr" > 83 < / span > b4/copy-to-ah 2/imm8/read-drive
< span id = "L84" class = "LineNr" > 84 < / span > < span class = "subxComment" > # dl comes conveniently initialized at boot time with the index of the device being booted< / span >
< span id = "L85" class = "LineNr" > 85 < / span > b5/copy-to-ch 0/imm8/cylinder
< span id = "L86" class = "LineNr" > 86 < / span > b6/copy-to-dh 2/imm8/head
< span id = "L87" class = "LineNr" > 87 < / span > b1/copy-to-cl 1/imm8/sector < span class = "subxComment" > # 1-based< / span >
< span id = "L88" class = "LineNr" > 88 < / span > b0/copy-to-al 0x7e/imm8/num-sectors < span class = "subxComment" > # 2*63 = 126< / span >
< span id = "L89" class = "LineNr" > 89 < / span > < span class = "subxComment" > # address to write sectors to = es:bx = 0x17800, contiguous with boot segment< / span >
< span id = "L90" class = "LineNr" > 90 < / span > bb/copy-to-bx 0x1780/imm16
< span id = "L91" class = "LineNr" > 91 < / span > 8e/-> seg 3/mod/direct 3/rm32/bx 0/r32/es
< span id = "L92" class = "LineNr" > 92 < / span > bb/copy-to-bx 0/imm16
< span id = "L93" class = "LineNr" > 93 < / span > cd/syscall 0x13/imm8/bios-disk-services
< span id = "L94" class = "LineNr" > 94 < / span > 0f 82/jump-if-carry < a href = 'boot.subx.html#L146' > disk_error< / a > /disp16
< span id = "L95" class = "LineNr" > 95 < / span >
< span id = "L96" class = "LineNr" > 96 < / span > < span class = "subxComment" > # load two more tracks of disk into addresses [0x27400, 0x37000)< / span >
< span id = "L97" class = "LineNr" > 97 < / span > b4/copy-to-ah 2/imm8/read-drive
< span id = "L98" class = "LineNr" > 98 < / span > < span class = "subxComment" > # dl comes conveniently initialized at boot time with the index of the device being booted< / span >
< span id = "L99" class = "LineNr" > 99 < / span > b5/copy-to-ch 0/imm8/cylinder
< span id = "L100" class = "LineNr" > 100 < / span > b6/copy-to-dh 4/imm8/head
< span id = "L101" class = "LineNr" > 101 < / span > b1/copy-to-cl 1/imm8/sector < span class = "subxComment" > # 1-based< / span >
< span id = "L102" class = "LineNr" > 102 < / span > b0/copy-to-al 0x7e/imm8/num-sectors < span class = "subxComment" > # 2*63 = 126< / span >
< span id = "L103" class = "LineNr" > 103 < / span > < span class = "subxComment" > # address to write sectors to = es:bx = 0x27400, contiguous with boot segment< / span >
< span id = "L104" class = "LineNr" > 104 < / span > bb/copy-to-bx 0x2740/imm16
< span id = "L105" class = "LineNr" > 105 < / span > 8e/-> seg 3/mod/direct 3/rm32/bx 0/r32/es
< span id = "L106" class = "LineNr" > 106 < / span > bb/copy-to-bx 0/imm16
< span id = "L107" class = "LineNr" > 107 < / span > cd/syscall 0x13/imm8/bios-disk-services
< span id = "L108" class = "LineNr" > 108 < / span > 0f 82/jump-if-carry < a href = 'boot.subx.html#L146' > disk_error< / a > /disp16
< span id = "L109" class = "LineNr" > 109 < / span >
< span id = "L110" class = "LineNr" > 110 < / span > < span class = "subxComment" > # reset es< / span >
< span id = "L111" class = "LineNr" > 111 < / span > bb/copy-to-bx 0/imm16
< span id = "L112" class = "LineNr" > 112 < / span > 8e/-> seg 3/mod/direct 3/rm32/bx 0/r32/es
< span id = "L113" class = "LineNr" > 113 < / span >
< span id = "L114" class = "LineNr" > 114 < / span > < span class = "subxComment" > # adjust video mode< / span >
< span id = "L115" class = "LineNr" > 115 < / span > b4/copy-to-ah 0x4f/imm8 < span class = "subxComment" > # VBE commands< / span >
< span id = "L116" class = "LineNr" > 116 < / span > b0/copy-to-al 2/imm8 < span class = "subxComment" > # set video mode< / span >
< span id = "L117" class = "LineNr" > 117 < / span > bb/copy-to-bx 0x4105/imm16 < span class = "subxComment" > # 0x0105 | 0x4000< / span >
< span id = "L118" class = "LineNr" > 118 < / span > < span class = "subxComment" > # 0x0105 = graphics mode 1024x768x256< / span >
< span id = "L119" class = "LineNr" > 119 < / span > < span class = "subxComment" > # (alternative candidate: 0x0101 for 640x480x256)< / span >
< span id = "L120" class = "LineNr" > 120 < / span > < span class = "subxComment" > # 0x4000 bit = configure linear frame buffer in Bochs emulator; hopefully this doesn't hurt anything when running natively< / span >
< span id = "L121" class = "LineNr" > 121 < / span > cd/syscall 0x10/imm8/bios-video-services
< span id = "L122" class = "LineNr" > 122 < / span >
< span id = "L123" class = "LineNr" > 123 < / span > < span class = "subxComment" > # load information for the (hopefully) current video mode< / span >
< span id = "L124" class = "LineNr" > 124 < / span > < span class = "subxComment" > # mostly just for the address to the linear frame buffer< / span >
< span id = "L125" class = "LineNr" > 125 < / span > b4/copy-to-ah 0x4f/imm8 < span class = "subxComment" > # VBE commands< / span >
< span id = "L126" class = "LineNr" > 126 < / span > b0/copy-to-al 1/imm8 < span class = "subxComment" > # get video mode info< / span >
< span id = "L127" class = "LineNr" > 127 < / span > b9/copy-to-cx 0x0105/imm16 < span class = "subxComment" > # mode we requested< / span >
< span id = "L128" class = "LineNr" > 128 < / span > bf/copy-to-di < span class = "SpecialChar" > < a href = 'boot.subx.html#L513' > Video-mode-info< / a > < / span > /imm16
< span id = "L129" class = "LineNr" > 129 < / span > cd/syscall 0x10/imm8/bios-video-services
< span id = "L130" class = "LineNr" > 130 < / span >
< span id = "L131" class = "LineNr" > 131 < / span > < span class = "subxComment" > ## switch to 32-bit mode< / span >
< span id = "L132" class = "LineNr" > 132 < / span > < span class = "subxComment" > # load global descriptor table< / span >
< span id = "L133" class = "LineNr" > 133 < / span > < span class = "subxComment" > # We can't refer to the label directly because SubX doesn't do the right< / span >
< span id = "L134" class = "LineNr" > 134 < / span > < span class = "subxComment" > # thing for lgdt, so rather than make errors worse in most places we instead< / span >
< span id = "L135" class = "LineNr" > 135 < / span > < span class = "subxComment" > # pin gdt_descriptor below.< / span >
< span id = "L136" class = "LineNr" > 136 < / span > 0f 01 2/subop/lgdt 0/mod/indirect 6/rm32/use-disp16 0x7ce0/disp16/gdt_descriptor
< span id = "L137" class = "LineNr" > 137 < / span > < span class = "subxComment" > # enable paging< / span >
< span id = "L138" class = "LineNr" > 138 < / span > 0f 20/< -cr 3/mod/direct 0/rm32/eax 0/r32/cr0
< span id = "L139" class = "LineNr" > 139 < / span > 66 83 1/subop/or 3/mod/direct 0/rm32/eax 1/imm8 < span class = "subxComment" > # eax < - or 0x1< / span >
< span id = "L140" class = "LineNr" > 140 < / span > 0f 22/-> cr 3/mod/direct 0/rm32/eax 0/r32/cr0
< span id = "L141" class = "LineNr" > 141 < / span > < span class = "subxComment" > # far jump to initialize_32bit_mode that sets cs to offset 8 in the gdt in the process< / span >
< span id = "L142" class = "LineNr" > 142 < / span > < span class = "subxComment" > # We can't refer to the label directly because SubX doesn't have syntax for< / span >
< span id = "L143" class = "LineNr" > 143 < / span > < span class = "subxComment" > # segment selectors. So we instead pin initialize_32bit_mode below.< / span >
< span id = "L144" class = "LineNr" > 144 < / span > ea/jump-far-absolute 0x00087d00/disp32 < span class = "subxComment" > # address 0x7d00 in offset 8 of the gdt< / span >
< span id = "L145" class = "LineNr" > 145 < / span >
< span id = "L146" class = "LineNr" > 146 < / span > < span class = "subxFunction" > disk_error< / span > :
< span id = "L147" class = "LineNr" > 147 < / span > < span class = "subxComment" > # print 'D' to top-left of screen to indicate disk error< / span >
< span id = "L148" class = "LineNr" > 148 < / span > < span class = "subxComment" > # *0xb8000 < - 0x0f44< / span >
< span id = "L149" class = "LineNr" > 149 < / span > bb/copy-to-bx 0xb800/imm16
< span id = "L150" class = "LineNr" > 150 < / span > 8e/-> seg 3/mod/direct 3/rm32/bx 3/r32/ds
< span id = "L151" class = "LineNr" > 151 < / span > b0/copy-to-al 0x44/imm8/D
< span id = "L152" class = "LineNr" > 152 < / span > b4/copy-to-ah 0x0f/imm8/white-on-black
< span id = "L153" class = "LineNr" > 153 < / span > bb/copy-to-bx 0/imm16
< span id = "L154" class = "LineNr" > 154 < / span > 89/< - 0/mod/indirect 7/rm32/bx 0/r32/ax < span class = "subxComment" > # *ds:bx < - ax< / span >
< span id = "L155" class = "LineNr" > 155 < / span > < span class = "subxComment" > # loop forever< / span >
< span id = "L156" class = "LineNr" > 156 < / span > {
< span id = "L157" class = "LineNr" > 157 < / span > eb/jump < span class = "Constant" > loop< / span > /disp8
< span id = "L158" class = "LineNr" > 158 < / span > }
< span id = "L159" class = "LineNr" > 159 < / span >
< span id = "L160" class = "LineNr" > 160 < / span > < span class = "subxComment" > ## GDT: 3 records of 8 bytes each< / span >
< span id = "L161" class = "LineNr" > 161 < / span > == data 0x7ce0
< span id = "L162" class = "LineNr" > 162 < / span > < span class = "subxFunction" > gdt_descriptor< / span > :
< span id = "L163" class = "LineNr" > 163 < / span > 0x17/imm16 < span class = "subxComment" > # final index of gdt = size of gdt - 1< / span >
< span id = "L164" class = "LineNr" > 164 < / span > < a href = 'boot.subx.html#L166' > gdt_start< / a > /imm32/start
< span id = "L165" class = "LineNr" > 165 < / span >
< span id = "L166" class = "LineNr" > 166 < / span > < span class = "subxFunction" > gdt_start< / span > :
< span id = "L167" class = "LineNr" > 167 < / span > < span class = "subxComment" > # offset 0: gdt_null: mandatory null descriptor< / span >
< span id = "L168" class = "LineNr" > 168 < / span > 00 00 00 00 00 00 00 00
< span id = "L169" class = "LineNr" > 169 < / span > < span class = "subxComment" > # offset 8: gdt_code< / span >
< span id = "L170" class = "LineNr" > 170 < / span > ff ff < span class = "subxComment" > # limit[0:16]< / span >
< span id = "L171" class = "LineNr" > 171 < / span > 00 00 00 < span class = "subxComment" > # base[0:24]< / span >
< span id = "L172" class = "LineNr" > 172 < / span > 9a < span class = "subxComment" > # 1/present 00/privilege 1/descriptor type = 1001b< / span >
< span id = "L173" class = "LineNr" > 173 < / span > < span class = "subxComment" > # 1/code 0/conforming 1/readable 0/accessed = 1010b< / span >
< span id = "L174" class = "LineNr" > 174 < / span > cf < span class = "subxComment" > # 1/granularity 1/32-bit 0/64-bit-segment 0/AVL = 1100b< / span >
< span id = "L175" class = "LineNr" > 175 < / span > < span class = "subxComment" > # limit[16:20] = 1111b< / span >
< span id = "L176" class = "LineNr" > 176 < / span > 00 < span class = "subxComment" > # base[24:32]< / span >
< span id = "L177" class = "LineNr" > 177 < / span > < span class = "subxComment" > # offset 16: gdt_data< / span >
< span id = "L178" class = "LineNr" > 178 < / span > ff ff < span class = "subxComment" > # limit[0:16]< / span >
< span id = "L179" class = "LineNr" > 179 < / span > 00 00 00 < span class = "subxComment" > # base[0:24]< / span >
< span id = "L180" class = "LineNr" > 180 < / span > 92 < span class = "subxComment" > # 1/present 00/privilege 1/descriptor type = 1001b< / span >
< span id = "L181" class = "LineNr" > 181 < / span > < span class = "subxComment" > # 0/data 0/conforming 1/readable 0/accessed = 0010b< / span >
< span id = "L182" class = "LineNr" > 182 < / span > cf < span class = "subxComment" > # same as gdt_code< / span >
< span id = "L183" class = "LineNr" > 183 < / span > 00 < span class = "subxComment" > # base[24:32]< / span >
< span id = "L184" class = "LineNr" > 184 < / span > < span class = "subxComment" > # gdt_end:< / span >
2021-03-24 00:31:08 +00:00
< span id = "L185" class = "LineNr" > 185 < / span >
< span id = "L186" class = "LineNr" > 186 < / span > < span class = "subxComment" > ## 32-bit code from this point< / span >
< span id = "L187" class = "LineNr" > 187 < / span >
< span id = "L188" class = "LineNr" > 188 < / span > == code 0x7d00
< span id = "L189" class = "LineNr" > 189 < / span > < span class = "subxFunction" > initialize_32bit_mode< / span > :
< span id = "L190" class = "LineNr" > 190 < / span > 66 b8/copy-to-ax 0x10/imm16 < span class = "subxComment" > # offset 16 from gdt_start< / span >
< span id = "L191" class = "LineNr" > 191 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 3/r32/ds
< span id = "L192" class = "LineNr" > 192 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 2/r32/ss
< span id = "L193" class = "LineNr" > 193 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 0/r32/es
< span id = "L194" class = "LineNr" > 194 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 4/r32/fs
< span id = "L195" class = "LineNr" > 195 < / span > 8e/-> seg 3/mod/direct 0/rm32/ax 5/r32/gs
< span id = "L196" class = "LineNr" > 196 < / span >
< span id = "L197" class = "LineNr" > 197 < / span > bc/copy-to-esp 0x00070000/imm32
< span id = "L198" class = "LineNr" > 198 < / span >
< span id = "L199" class = "LineNr" > 199 < / span > < span class = "subxComment" > ## load interrupt handlers< / span >
< span id = "L200" class = "LineNr" > 200 < / span > < span class = "subxComment" > # We can't refer to the label directly because SubX doesn't do the right< / span >
< span id = "L201" class = "LineNr" > 201 < / span > < span class = "subxComment" > # thing for lidt, so rather than make errors worse in most places we instead< / span >
< span id = "L202" class = "LineNr" > 202 < / span > < span class = "subxComment" > # pin idt_descriptor below.< / span >
2021-03-24 05:27:46 +00:00
< span id = "L203" class = "LineNr" > 203 < / span > 0f 01 3/subop/lidt 0/mod/indirect 5/rm32/use-disp32 0x7e00/disp32/idt_descriptor
2021-03-24 00:31:08 +00:00
< span id = "L204" class = "LineNr" > 204 < / span >
< span id = "L205" class = "LineNr" > 205 < / span > < span class = "subxComment" > # For now, not bothering reprogramming the IRQ to not conflict with software< / span >
< span id = "L206" class = "LineNr" > 206 < / span > < span class = "subxComment" > # exceptions.< / span >
< span id = "L207" class = "LineNr" > 207 < / span > < span class = "subxComment" > # < a href = "https://wiki.osdev.org/index.php?title=8259_PIC&oldid=24650#Protected_Mode" > https://wiki.osdev.org/index.php?title=8259_PIC& oldid=24650#Protected_Mode< / a > < / span >
< span id = "L208" class = "LineNr" > 208 < / span > < span class = "subxComment" > #< / span >
< span id = "L209" class = "LineNr" > 209 < / span > < span class = "subxComment" > # Interrupt 1 (keyboard) conflicts with debugger faults. We don't use a< / span >
< span id = "L210" class = "LineNr" > 210 < / span > < span class = "subxComment" > # debugger.< / span >
< span id = "L211" class = "LineNr" > 211 < / span > < span class = "subxComment" > # Reference:< / span >
< span id = "L212" class = "LineNr" > 212 < / span > < span class = "subxComment" > # < a href = "https://wiki.osdev.org/Exceptions" > https://wiki.osdev.org/Exceptions< / a > < / span >
< span id = "L213" class = "LineNr" > 213 < / span >
< span id = "L214" class = "LineNr" > 214 < / span > < span class = "subxComment" > # enable keyboard IRQ (1)< / span >
< span id = "L215" class = "LineNr" > 215 < / span > b0/copy-to-al 0xfd/imm8 < span class = "subxComment" > # disable mask for IRQ1< / span >
< span id = "L216" class = "LineNr" > 216 < / span > e6/write-al-into-port 0x21/imm8
< span id = "L217" class = "LineNr" > 217 < / span >
< span id = "L218" class = "LineNr" > 218 < / span > fb/enable-interrupts
< span id = "L219" class = "LineNr" > 219 < / span >
2021-03-24 05:27:46 +00:00
< span id = "L220" class = "LineNr" > 220 < / span > (< a href = 'boot.subx.html#L1277' > initialize-mouse< / a > )
< span id = "L221" class = "LineNr" > 221 < / span >
< span id = "L222" class = "LineNr" > 222 < / span > < span class = "subxComment" > ## enable floating point< / span >
< span id = "L223" class = "LineNr" > 223 < / span > db/floating-point-coprocessor e3/initialize
< span id = "L224" class = "LineNr" > 224 < / span > < span class = "subxComment" > # eax < - cr4< / span >
< span id = "L225" class = "LineNr" > 225 < / span > 0f 20/< -cr 3/mod/direct 0/rm32/eax 4/r32/cr4
< span id = "L226" class = "LineNr" > 226 < / span > < span class = "subxComment" > # eax < - or bit 9< / span >
< span id = "L227" class = "LineNr" > 227 < / span > 0f ba/bit-test 5/subop/bit-test-and-set 3/mod/direct 0/rm32/eax 9/imm8
< span id = "L228" class = "LineNr" > 228 < / span > < span class = "subxComment" > # cr4 < - eax< / span >
< span id = "L229" class = "LineNr" > 229 < / span > 0f 22/-> cr 3/mod/direct 0/rm32/eax 4/r32/cr4
2021-03-24 00:31:08 +00:00
< span id = "L230" class = "LineNr" > 230 < / span >
2021-03-24 05:27:46 +00:00
< span id = "L231" class = "LineNr" > 231 < / span > e9/jump < span class = "SpecialChar" > Entry< / span > /disp32
< span id = "L232" class = "LineNr" > 232 < / span >
< span id = "L233" class = "LineNr" > 233 < / span > == boot-sector-marker 0x7dfe
< span id = "L234" class = "LineNr" > 234 < / span > < span class = "subxComment" > # final 2 bytes of boot sector< / span >
< span id = "L235" class = "LineNr" > 235 < / span > 55 aa
< span id = "L236" class = "LineNr" > 236 < / span >
< span id = "L237" class = "LineNr" > 237 < / span > < span class = "subxComment" > ## sector 2 onwards loaded by load_disk, not automatically on boot< / span >
< span id = "L238" class = "LineNr" > 238 < / span >
< span id = "L239" class = "LineNr" > 239 < / span > == data 0x7e00
< span id = "L240" class = "LineNr" > 240 < / span > < span class = "subxFunction" > idt_descriptor< / span > :
< span id = "L241" class = "LineNr" > 241 < / span > ff 03 < span class = "subxComment" > # final index of idt = size of idt - 1< / span >
< span id = "L242" class = "LineNr" > 242 < / span > < a href = 'boot.subx.html#L246' > idt_start< / a > /imm32/start
< span id = "L243" class = "LineNr" > 243 < / span >
< span id = "L244" class = "Folded" > 244 < / span > < span class = "Folded" > +-- 55 lines: # interrupt descriptor table ----------------------------------------------------------------------------------------------------------------------------------------------< / span >
< span id = "L299" class = "LineNr" > 299 < / span >
< span id = "L300" class = "LineNr" > 300 < / span > == code
< span id = "L301" class = "LineNr" > 301 < / span >
< span id = "L302" class = "LineNr" > 302 < / span > < span class = "subxFunction" > null-interrupt-handler< / span > :
< span id = "L303" class = "LineNr" > 303 < / span > cf/return-from-interrupt
< span id = "L304" class = "LineNr" > 304 < / span >
< span id = "L305" class = "LineNr" > 305 < / span > < span class = "subxFunction" > keyboard-interrupt-handler< / span > :
< span id = "L306" class = "LineNr" > 306 < / span > < span class = "subxComment" > # prologue< / span >
< span id = "L307" class = "LineNr" > 307 < / span > fa/disable-interrupts
< span id = "L308" class = "LineNr" > 308 < / span > 60/push-all-registers
< span id = "L309" class = "LineNr" > 309 < / span > < span class = "subxComment" > # acknowledge interrupt< / span >
< span id = "L310" class = "LineNr" > 310 < / span > b0/copy-to-al 0x20/imm8
< span id = "L311" class = "LineNr" > 311 < / span > e6/write-al-into-port 0x20/imm8
< span id = "L312" class = "LineNr" > 312 < / span > 31/xor %eax 0/r32/eax
< span id = "L313" class = "LineNr" > 313 < / span > < span class = "subxComment" > # check output buffer of 8042 keyboard controller (< a href = "https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)" > https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)< / a > < / span >
< span id = "L314" class = "LineNr" > 314 < / span > e4/read-port-into-al 0x64/imm8
< span id = "L315" class = "LineNr" > 315 < / span > a8/test-bits-in-al 0x01/imm8 < span class = "subxComment" > # set zf if bit 0 (least significant) is not set< / span >
< span id = "L316" class = "LineNr" > 316 < / span > 74/jump-if-not-set $keyboard-interrupt-handler:epilogue/disp8
< span id = "L317" class = "LineNr" > 317 < / span > < span class = "subxH1Comment" > # - if keyboard buffer is full, return< / span >
< span id = "L318" class = "LineNr" > 318 < / span > < span class = "subxComment" > # var dest-addr/ecx: (addr byte) = (keyboard-buffer + *keyboard-buffer:write)< / span >
< span id = "L319" class = "LineNr" > 319 < / span > 31/xor %ecx 1/r32/ecx
< span id = "L320" class = "LineNr" > 320 < / span > 8a/byte-> *< span class = "SpecialChar" > Keyboard-buffer< / span > :< a href = '108write.subx.html#L11' > write< / a > 1/r32/cl
< span id = "L321" class = "LineNr" > 321 < / span > 81 0/subop/add %ecx < span class = "SpecialChar" > Keyboard-buffer< / span > :data/imm32
< span id = "L322" class = "LineNr" > 322 < / span > < span class = "subxComment" > # al = *dest-addr< / span >
< span id = "L323" class = "LineNr" > 323 < / span > 8a/byte-> *ecx 0/r32/al
< span id = "L324" class = "LineNr" > 324 < / span > < span class = "subxComment" > # if (al != 0) return< / span >
< span id = "L325" class = "LineNr" > 325 < / span > 3c/compare-al-and 0/imm8
< span id = "L326" class = "LineNr" > 326 < / span > 75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8
< span id = "L327" class = "LineNr" > 327 < / span > < span class = "subxH1Comment" > # - read keycode< / span >
< span id = "L328" class = "LineNr" > 328 < / span > e4/read-port-into-al 0x60/imm8
< span id = "L329" class = "LineNr" > 329 < / span > < span class = "subxH1Comment" > # - key released< / span >
< span id = "L330" class = "LineNr" > 330 < / span > < span class = "subxComment" > # if (al == 0xaa) shift = false # left shift is being lifted< / span >
< span id = "L331" class = "LineNr" > 331 < / span > {
< span id = "L332" class = "LineNr" > 332 < / span > 3c/compare-al-and 0xaa/imm8
< span id = "L333" class = "LineNr" > 333 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L334" class = "LineNr" > 334 < / span > < span class = "subxComment" > # *shift = 0< / span >
< span id = "L335" class = "LineNr" > 335 < / span > c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32
< span id = "L336" class = "LineNr" > 336 < / span > }
< span id = "L337" class = "LineNr" > 337 < / span > < span class = "subxComment" > # if (al == 0xb6) shift = false # right shift is being lifted< / span >
< span id = "L338" class = "LineNr" > 338 < / span > {
< span id = "L339" class = "LineNr" > 339 < / span > 3c/compare-al-and 0xb6/imm8
< span id = "L340" class = "LineNr" > 340 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L341" class = "LineNr" > 341 < / span > < span class = "subxComment" > # *shift = 0< / span >
< span id = "L342" class = "LineNr" > 342 < / span > c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32
< span id = "L343" class = "LineNr" > 343 < / span > }
< span id = "L344" class = "LineNr" > 344 < / span > < span class = "subxComment" > # if (al == 0x9d) ctrl = false # ctrl is being lifted< / span >
< span id = "L345" class = "LineNr" > 345 < / span > {
< span id = "L346" class = "LineNr" > 346 < / span > 3c/compare-al-and 0x9d/imm8
< span id = "L347" class = "LineNr" > 347 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L348" class = "LineNr" > 348 < / span > < span class = "subxComment" > # *ctrl = 0< / span >
< span id = "L349" class = "LineNr" > 349 < / span > c7 0/subop/copy *Keyboard-ctrl-pressed? 0/imm32
< span id = "L350" class = "LineNr" > 350 < / span > }
< span id = "L351" class = "LineNr" > 351 < / span > < span class = "subxComment" > # if (al & 0x80) a key is being lifted; return< / span >
< span id = "L352" class = "LineNr" > 352 < / span > 50/push-eax
< span id = "L353" class = "LineNr" > 353 < / span > 24/and-al-with 0x80/imm8
< span id = "L354" class = "LineNr" > 354 < / span > 3c/compare-al-and 0/imm8
< span id = "L355" class = "LineNr" > 355 < / span > 58/pop-to-eax
< span id = "L356" class = "LineNr" > 356 < / span > 75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8
< span id = "L357" class = "LineNr" > 357 < / span > < span class = "subxH1Comment" > # - key pressed< / span >
< span id = "L358" class = "LineNr" > 358 < / span > < span class = "subxComment" > # if (al == 0x2a) shift = true, return # left shift pressed< / span >
< span id = "L359" class = "LineNr" > 359 < / span > {
< span id = "L360" class = "LineNr" > 360 < / span > 3c/compare-al-and 0x2a/imm8
< span id = "L361" class = "LineNr" > 361 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L362" class = "LineNr" > 362 < / span > < span class = "subxComment" > # *shift = 1< / span >
< span id = "L363" class = "LineNr" > 363 < / span > c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32
< span id = "L364" class = "LineNr" > 364 < / span > < span class = "subxComment" > # return< / span >
< span id = "L365" class = "LineNr" > 365 < / span > eb/jump $keyboard-interrupt-handler:epilogue/disp8
< span id = "L366" class = "LineNr" > 366 < / span > }
< span id = "L367" class = "LineNr" > 367 < / span > < span class = "subxComment" > # if (al == 0x36) shift = true, return # right shift pressed< / span >
< span id = "L368" class = "LineNr" > 368 < / span > {
< span id = "L369" class = "LineNr" > 369 < / span > 3c/compare-al-and 0x36/imm8
< span id = "L370" class = "LineNr" > 370 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L371" class = "LineNr" > 371 < / span > < span class = "subxComment" > # *shift = 1< / span >
< span id = "L372" class = "LineNr" > 372 < / span > c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32
< span id = "L373" class = "LineNr" > 373 < / span > < span class = "subxComment" > # return< / span >
< span id = "L374" class = "LineNr" > 374 < / span > eb/jump $keyboard-interrupt-handler:epilogue/disp8
< span id = "L375" class = "LineNr" > 375 < / span > }
< span id = "L376" class = "LineNr" > 376 < / span > < span class = "subxComment" > # if (al == 0x1d) ctrl = true, return< / span >
< span id = "L377" class = "LineNr" > 377 < / span > {
< span id = "L378" class = "LineNr" > 378 < / span > 3c/compare-al-and 0x1d/imm8
< span id = "L379" class = "LineNr" > 379 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L380" class = "LineNr" > 380 < / span > < span class = "subxComment" > # *ctrl = 1< / span >
< span id = "L381" class = "LineNr" > 381 < / span > c7 0/subop/copy *Keyboard-ctrl-pressed? 1/imm32
< span id = "L382" class = "LineNr" > 382 < / span > < span class = "subxComment" > # return< / span >
< span id = "L383" class = "LineNr" > 383 < / span > eb/jump $keyboard-interrupt-handler:epilogue/disp8
< span id = "L384" class = "LineNr" > 384 < / span > }
< span id = "L385" class = "LineNr" > 385 < / span > < span class = "subxH1Comment" > # - convert key to character< / span >
< span id = "L386" class = "LineNr" > 386 < / span > < span class = "subxComment" > # if (shift) use keyboard shift map< / span >
< span id = "L387" class = "LineNr" > 387 < / span > {
< span id = "L388" class = "LineNr" > 388 < / span > 81 7/subop/compare *Keyboard-shift-pressed? 0/imm32
< span id = "L389" class = "LineNr" > 389 < / span > 74/jump-if-= < span class = "Constant" > break< / span > /disp8
< span id = "L390" class = "LineNr" > 390 < / span > < span class = "subxComment" > # sigils don't currently support labels inside *(eax+label)< / span >
< span id = "L391" class = "LineNr" > 391 < / span > 05/add-to-eax < span class = "SpecialChar" > < a href = 'boot.subx.html#L471' > Keyboard-shift-map< / a > < / span > /imm32
< span id = "L392" class = "LineNr" > 392 < / span > 8a/byte-> *eax 0/r32/al
< span id = "L393" class = "LineNr" > 393 < / span > eb/jump $keyboard-interrupt-handler:select-map-done/disp8
< span id = "L394" class = "LineNr" > 394 < / span > }
< span id = "L395" class = "LineNr" > 395 < / span > < span class = "subxComment" > # if (ctrl) al = *(ctrl map + al)< / span >
< span id = "L396" class = "LineNr" > 396 < / span > {
< span id = "L397" class = "LineNr" > 397 < / span > 81 7/subop/compare *Keyboard-ctrl-pressed? 0/imm32
< span id = "L398" class = "LineNr" > 398 < / span > 74/jump-if-= < span class = "Constant" > break< / span > /disp8
< span id = "L399" class = "LineNr" > 399 < / span > 05/add-to-eax < span class = "SpecialChar" > < a href = 'boot.subx.html#L497' > Keyboard-ctrl-map< / a > < / span > /imm32
< span id = "L400" class = "LineNr" > 400 < / span > 8a/byte-> *eax 0/r32/al
< span id = "L401" class = "LineNr" > 401 < / span > eb/jump $keyboard-interrupt-handler:select-map-done/disp8
< span id = "L402" class = "LineNr" > 402 < / span > }
< span id = "L403" class = "LineNr" > 403 < / span > < span class = "subxComment" > # otherwise al = *(normal map + al)< / span >
< span id = "L404" class = "LineNr" > 404 < / span > 05/add-to-eax < span class = "SpecialChar" > < a href = 'boot.subx.html#L443' > Keyboard-normal-map< / a > < / span > /imm32
< span id = "L405" class = "LineNr" > 405 < / span > 8a/byte-> *eax 0/r32/al
< span id = "L406" class = "LineNr" > 406 < / span > < span class = "Constant" > $keyboard-interrupt-handler:select-map-done< / span > :
< span id = "L407" class = "LineNr" > 407 < / span > < span class = "subxH1Comment" > # - if there's no character mapping, return< / span >
< span id = "L408" class = "LineNr" > 408 < / span > {
< span id = "L409" class = "LineNr" > 409 < / span > 3c/compare-al-and 0/imm8
< span id = "L410" class = "LineNr" > 410 < / span > 74/jump-if-= < span class = "Constant" > break< / span > /disp8
< span id = "L411" class = "LineNr" > 411 < / span > < span class = "subxH1Comment" > # - store al in keyboard buffer< / span >
< span id = "L412" class = "LineNr" > 412 < / span > 88/< - *ecx 0/r32/al
< span id = "L413" class = "LineNr" > 413 < / span > < span class = "subxComment" > # increment index< / span >
< span id = "L414" class = "LineNr" > 414 < / span > fe/increment-byte *< span class = "SpecialChar" > Keyboard-buffer< / span > :< a href = '108write.subx.html#L11' > write< / a >
< span id = "L415" class = "LineNr" > 415 < / span > < span class = "subxComment" > # clear top nibble of index (keyboard buffer is circular)< / span >
< span id = "L416" class = "LineNr" > 416 < / span > 80 4/subop/and-byte *< span class = "SpecialChar" > Keyboard-buffer< / span > :< a href = '108write.subx.html#L11' > write< / a > 0x0f/imm8
< span id = "L417" class = "LineNr" > 417 < / span > }
< span id = "L418" class = "LineNr" > 418 < / span > < span class = "Constant" > $keyboard-interrupt-handler:epilogue< / span > :
< span id = "L419" class = "LineNr" > 419 < / span > < span class = "subxComment" > # epilogue< / span >
< span id = "L420" class = "LineNr" > 420 < / span > 61/pop-all-registers
< span id = "L421" class = "LineNr" > 421 < / span > fb/enable-interrupts
< span id = "L422" class = "LineNr" > 422 < / span > cf/return-from-interrupt
< span id = "L423" class = "LineNr" > 423 < / span >
< span id = "L424" class = "LineNr" > 424 < / span > == data
< span id = "L425" class = "LineNr" > 425 < / span > Keyboard-shift-pressed?: < span class = "subxComment" > # boolean< / span >
< span id = "L426" class = "LineNr" > 426 < / span > 0/imm32
< span id = "L427" class = "LineNr" > 427 < / span >
< span id = "L428" class = "LineNr" > 428 < / span > Keyboard-ctrl-pressed?: < span class = "subxComment" > # boolean< / span >
< span id = "L429" class = "LineNr" > 429 < / span > 0/imm32
< span id = "L430" class = "LineNr" > 430 < / span >
< span id = "L431" class = "LineNr" > 431 < / span > < span class = "subxComment" > # var keyboard circular buffer< / span >
< span id = "L432" class = "LineNr" > 432 < / span > < span class = "SpecialChar" > Keyboard-buffer< / span > :< a href = '108write.subx.html#L11' > write< / a > : < span class = "subxComment" > # nibble< / span >
< span id = "L433" class = "LineNr" > 433 < / span > 0/imm32
< span id = "L434" class = "LineNr" > 434 < / span > < span class = "SpecialChar" > Keyboard-buffer< / span > :read: < span class = "subxComment" > # nibble< / span >
< span id = "L435" class = "LineNr" > 435 < / span > 0/imm32
< span id = "L436" class = "LineNr" > 436 < / span > < span class = "SpecialChar" > Keyboard-buffer< / span > :data: < span class = "subxComment" > # byte[16]< / span >
< span id = "L437" class = "LineNr" > 437 < / span > 00 00 00 00
< span id = "L438" class = "LineNr" > 438 < / span > 00 00 00 00
< span id = "L439" class = "LineNr" > 439 < / span > 00 00 00 00
< span id = "L440" class = "LineNr" > 440 < / span > 00 00 00 00
< span id = "L441" class = "LineNr" > 441 < / span >
< span id = "L442" class = "Folded" > 442 < / span > < span class = "Folded" > +-- 70 lines: # Keyboard maps for translating keys to ASCII -----------------------------------------------------------------------------------------------------------------------------< / span >
< span id = "L512" class = "LineNr" > 512 < / span >
< span id = "L513" class = "LineNr" > 513 < / span > < span class = "SpecialChar" > Video-mode-info< / span > :
< span id = "L514" class = "Folded" > 514 < / span > < span class = "Folded" > +-- 53 lines: # video mode info ---------------------------------------------------------------------------------------------------------------------------------------------------------< / span >
< span id = "L567" class = "LineNr" > 567 < / span >
< span id = "L568" class = "LineNr" > 568 < / span > < span class = "SpecialChar" > Font< / span > :
< span id = "L569" class = "Folded" > 569 < / span > < span class = "Folded" > +--236 lines: # Bitmaps for some ASCII characters (soon Unicode) ------------------------------------------------------------------------------------------------------------------------< / span >
< span id = "L805" class = "LineNr" > 805 < / span >
< span id = "L806" class = "LineNr" > 806 < / span > == code
< span id = "L807" class = "LineNr" > 807 < / span >
< span id = "L808" class = "LineNr" > 808 < / span > < span class = "subxComment" > ## Controlling IDE (ATA) hard disks< / span >
< span id = "L809" class = "LineNr" > 809 < / span > < span class = "subxComment" > # Uses 28-bit PIO mode.< / span >
< span id = "L810" class = "LineNr" > 810 < / span > < span class = "subxComment" > # Inspired by < a href = "https://colorforth.github.io/ide.html" > https://colorforth.github.io/ide.html< / a > < / span >
< span id = "L811" class = "LineNr" > 811 < / span > < span class = "subxComment" > #< / span >
< span id = "L812" class = "LineNr" > 812 < / span > < span class = "subxComment" > # Resources:< / span >
< span id = "L813" class = "LineNr" > 813 < / span > < span class = "subxComment" > # < a href = "https://wiki.osdev.org/ATA_PIO_Mode" > https://wiki.osdev.org/ATA_PIO_Mode< / a > < / span >
< span id = "L814" class = "LineNr" > 814 < / span > < span class = "subxComment" > # < a href = "https://forum.osdev.org/viewtopic.php?f=1&p=167798" > https://forum.osdev.org/viewtopic.php?f=1& p=167798< / a > < / span >
< span id = "L815" class = "LineNr" > 815 < / span > < span class = "subxComment" > # read-sector, according to < a href = "https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf" > https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf< / a > < / span >
< span id = "L816" class = "LineNr" > 816 < / span >
< span id = "L817" class = "LineNr" > 817 < / span > < span class = "subxFunction" > load-first-sector-from-primary-bus-secondary-drive< / span > : < span class = "subxComment" > # out: (addr stream byte)< / span >
< span id = "L818" class = "LineNr" > 818 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L819" class = "LineNr" > 819 < / span > 55/push-ebp
< span id = "L820" class = "LineNr" > 820 < / span > 89/< - %ebp 4/r32/esp
< span id = "L821" class = "LineNr" > 821 < / span > < span class = "subxS1Comment" > # . save registers< / span >
< span id = "L822" class = "LineNr" > 822 < / span > 50/push-eax
< span id = "L823" class = "LineNr" > 823 < / span > 51/push-ecx
< span id = "L824" class = "LineNr" > 824 < / span > 52/push-edx
< span id = "L825" class = "LineNr" > 825 < / span > < span class = "subxComment" > # check for drive< / span >
< span id = "L826" class = "LineNr" > 826 < / span > (< a href = 'boot.subx.html#L951' > secondary-drive-exists?< / a > ) < span class = "subxComment" > # => eax< / span >
< span id = "L827" class = "LineNr" > 827 < / span > 3d/compare-eax-and 0/imm32/false
< span id = "L828" class = "LineNr" > 828 < / span > 0f 84/jump-if-= $load-first-sector-from-primary-bus-secondary-drive:end/disp32
< span id = "L829" class = "LineNr" > 829 < / span > < span class = "subxComment" > # kick off read< / span >
< span id = "L830" class = "LineNr" > 830 < / span > (< a href = 'boot.subx.html#L1011' > ata-drive-select< / a > 0xf0) < span class = "subxComment" > # primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0)< / span >
< span id = "L831" class = "LineNr" > 831 < / span > (< a href = 'boot.subx.html#L1031' > clear-ata-error< / a > )
< span id = "L832" class = "LineNr" > 832 < / span > (< a href = 'boot.subx.html#L1051' > ata-sector-count< / a > 1)
< span id = "L833" class = "LineNr" > 833 < / span > (< a href = 'boot.subx.html#L1071' > ata-lba< / a > 0 0 0) < span class = "subxComment" > # lower 24 bits of LBA, all 0< / span >
< span id = "L834" class = "LineNr" > 834 < / span > (< a href = 'boot.subx.html#L1129' > ata-command< / a > 0x20) < span class = "subxComment" > # read sectors with retries< / span >
< span id = "L835" class = "LineNr" > 835 < / span > < span class = "subxComment" > # poll for results< / span >
< span id = "L836" class = "LineNr" > 836 < / span > (< a href = 'boot.subx.html#L1149' > while-ata-busy< / a > )
< span id = "L837" class = "LineNr" > 837 < / span > (< a href = 'boot.subx.html#L1167' > until-ata-data-available< / a > )
< span id = "L838" class = "LineNr" > 838 < / span > < span class = "subxComment" > # emit results< / span >
< span id = "L839" class = "LineNr" > 839 < / span > 31/xor %eax 0/r32/eax
< span id = "L840" class = "LineNr" > 840 < / span > ba/copy-to-edx 0x1f0/imm32
< span id = "L841" class = "LineNr" > 841 < / span > b9/copy-to-ecx 0x200/imm32 < span class = "subxComment" > # 512 bytes per sector< / span >
< span id = "L842" class = "LineNr" > 842 < / span > {
< span id = "L843" class = "LineNr" > 843 < / span > 81 7/subop/compare %ecx 0/imm32
< span id = "L844" class = "LineNr" > 844 < / span > 74/jump-if-= < span class = "Constant" > break< / span > /disp8
< span id = "L845" class = "LineNr" > 845 < / span > 66 ed/read-port-dx-into-ax
< span id = "L846" class = "LineNr" > 846 < / span > < span class = "subxComment" > # write 2 bytes to stream one at a time< / span >
< span id = "L847" class = "LineNr" > 847 < / span > (< a href = '115write-byte.subx.html#L12' > append-byte< / a > *(ebp+8) %eax)
< span id = "L848" class = "LineNr" > 848 < / span > 49/decrement-ecx
< span id = "L849" class = "LineNr" > 849 < / span > c1/shift 5/subop/right-padding-zeroes %eax 8/imm8
< span id = "L850" class = "LineNr" > 850 < / span > (< a href = '115write-byte.subx.html#L12' > append-byte< / a > *(ebp+8) %eax)
< span id = "L851" class = "LineNr" > 851 < / span > 49/decrement-ecx
< span id = "L852" class = "LineNr" > 852 < / span > eb/jump < span class = "Constant" > loop< / span > /disp8
< span id = "L853" class = "LineNr" > 853 < / span > }
< span id = "L854" class = "LineNr" > 854 < / span > < span class = "Constant" > $load-first-sector-from-primary-bus-secondary-drive:end< / span > :
< span id = "L855" class = "LineNr" > 855 < / span > < span class = "subxS1Comment" > # . restore registers< / span >
< span id = "L856" class = "LineNr" > 856 < / span > 5a/pop-to-edx
< span id = "L857" class = "LineNr" > 857 < / span > 59/pop-to-ecx
< span id = "L858" class = "LineNr" > 858 < / span > 58/pop-to-eax
< span id = "L859" class = "LineNr" > 859 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L860" class = "LineNr" > 860 < / span > 89/< - %esp 5/r32/ebp
< span id = "L861" class = "LineNr" > 861 < / span > 5d/pop-to-ebp
< span id = "L862" class = "LineNr" > 862 < / span > c3/return
< span id = "L863" class = "LineNr" > 863 < / span >
< span id = "L864" class = "LineNr" > 864 < / span > < span class = "subxFunction" > store-first-sector-to-primary-bus-secondary-drive< / span > : < span class = "subxComment" > # in: (addr stream byte)< / span >
< span id = "L865" class = "LineNr" > 865 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L866" class = "LineNr" > 866 < / span > 55/push-ebp
< span id = "L867" class = "LineNr" > 867 < / span > 89/< - %ebp 4/r32/esp
< span id = "L868" class = "LineNr" > 868 < / span > < span class = "subxS1Comment" > # . save registers< / span >
< span id = "L869" class = "LineNr" > 869 < / span > 50/push-eax
< span id = "L870" class = "LineNr" > 870 < / span > 51/push-ecx
< span id = "L871" class = "LineNr" > 871 < / span > 52/push-edx
< span id = "L872" class = "LineNr" > 872 < / span > 53/push-ebx
< span id = "L873" class = "LineNr" > 873 < / span > < span class = "subxComment" > # check for drive< / span >
< span id = "L874" class = "LineNr" > 874 < / span > (< a href = 'boot.subx.html#L951' > secondary-drive-exists?< / a > ) < span class = "subxComment" > # => eax< / span >
< span id = "L875" class = "LineNr" > 875 < / span > 3d/compare-eax-and 0/imm32/false
< span id = "L876" class = "LineNr" > 876 < / span > 0f 84/jump-if-= $store-first-sector-to-primary-bus-secondary-drive:end/disp32
< span id = "L877" class = "LineNr" > 877 < / span > < span class = "subxComment" > # kick off write< / span >
< span id = "L878" class = "LineNr" > 878 < / span > (< a href = 'boot.subx.html#L1011' > ata-drive-select< / a > 0xf0) < span class = "subxComment" > # primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0)< / span >
< span id = "L879" class = "LineNr" > 879 < / span > (< a href = 'boot.subx.html#L1031' > clear-ata-error< / a > )
< span id = "L880" class = "LineNr" > 880 < / span > (< a href = 'boot.subx.html#L1051' > ata-sector-count< / a > 1)
< span id = "L881" class = "LineNr" > 881 < / span > (< a href = 'boot.subx.html#L1071' > ata-lba< / a > 0 0 0) < span class = "subxComment" > # lower 24 bits of LBA, all 0< / span >
< span id = "L882" class = "LineNr" > 882 < / span > (< a href = 'boot.subx.html#L1129' > ata-command< / a > 0x30) < span class = "subxComment" > # write sectors with retries< / span >
< span id = "L883" class = "LineNr" > 883 < / span > < span class = "subxComment" > # wait< / span >
< span id = "L884" class = "LineNr" > 884 < / span > (< a href = 'boot.subx.html#L1149' > while-ata-busy< / a > )
< span id = "L885" class = "LineNr" > 885 < / span > (< a href = 'boot.subx.html#L1185' > until-ata-ready-for-data< / a > )
< span id = "L886" class = "LineNr" > 886 < / span > < span class = "subxComment" > # send data< / span >
< span id = "L887" class = "LineNr" > 887 < / span > ba/copy-to-edx 0x1f0/imm32
< span id = "L888" class = "LineNr" > 888 < / span > b9/copy-to-ecx 0x200/imm32 < span class = "subxComment" > # 512 bytes per sector< / span >
< span id = "L889" class = "LineNr" > 889 < / span > < span class = "subxComment" > # var first-byte/ebx: byte< / span >
< span id = "L890" class = "LineNr" > 890 < / span > < span class = "subxComment" > # when it's more than 0xff, we're at an even-numbered byte< / span >
< span id = "L891" class = "LineNr" > 891 < / span > bb/copy-to-ebx 0xffff/imm32
< span id = "L892" class = "LineNr" > 892 < / span > < span class = "Constant" > $store-first-sector-to-primary-bus-secondary-drive:loop< / span > :
< span id = "L893" class = "LineNr" > 893 < / span > {
< span id = "L894" class = "LineNr" > 894 < / span > 81 7/subop/compare %ecx 0/imm32
< span id = "L895" class = "LineNr" > 895 < / span > 74/jump-if-= < span class = "Constant" > break< / span > /disp8
< span id = "L896" class = "LineNr" > 896 < / span > < span class = "subxComment" > # this loop is slow, but the ATA spec also requires a small delay< / span >
< span id = "L897" class = "LineNr" > 897 < / span > (< a href = '309stream.subx.html#L6' > stream-empty?< / a > *(ebp+8)) < span class = "subxComment" > # => eax< / span >
< span id = "L898" class = "LineNr" > 898 < / span > 3d/compare-eax-and 0/imm32/false
< span id = "L899" class = "LineNr" > 899 < / span > 75/jump-if-!= < span class = "Constant" > break< / span > /disp8
< span id = "L900" class = "LineNr" > 900 < / span > < span class = "subxComment" > # read byte from stream< / span >
< span id = "L901" class = "LineNr" > 901 < / span > (< a href = '112read-byte.subx.html#L13' > read-byte< / a > *(ebp+8)) < span class = "subxComment" > # => eax< / span >
< span id = "L902" class = "LineNr" > 902 < / span > < span class = "subxComment" > # if we're at an odd-numbered byte, save it to first-byte< / span >
< span id = "L903" class = "LineNr" > 903 < / span > 81 7/subop/compare %ebx 0xff/imm32
< span id = "L904" class = "LineNr" > 904 < / span > {
< span id = "L905" class = "LineNr" > 905 < / span > 7e/jump-if-< = < span class = "Constant" > break< / span > /disp8
< span id = "L906" class = "LineNr" > 906 < / span > 89/< - %ebx 0/r32/eax
< span id = "L907" class = "LineNr" > 907 < / span > eb/jump $store-first-sector-to-primary-bus-secondary-drive:< span class = "Constant" > loop< / span > /disp8
< span id = "L908" class = "LineNr" > 908 < / span > }
< span id = "L909" class = "LineNr" > 909 < / span > < span class = "subxComment" > # otherwise OR it with first-byte and write it out< / span >
< span id = "L910" class = "LineNr" > 910 < / span > c1/shift 4/subop/left %eax 8/imm8
< span id = "L911" class = "LineNr" > 911 < / span > 09/or %eax 3/r32/ebx
< span id = "L912" class = "LineNr" > 912 < / span > 66 ef/write-ax-into-port-dx
< span id = "L913" class = "LineNr" > 913 < / span > 49/decrement-ecx
< span id = "L914" class = "LineNr" > 914 < / span > 49/decrement-ecx
< span id = "L915" class = "LineNr" > 915 < / span > < span class = "subxComment" > # reset first-byte< / span >
< span id = "L916" class = "LineNr" > 916 < / span > bb/copy-to-ebx 0xffff/imm32
< span id = "L917" class = "LineNr" > 917 < / span > eb/jump < span class = "Constant" > loop< / span > /disp8
< span id = "L918" class = "LineNr" > 918 < / span > }
< span id = "L919" class = "LineNr" > 919 < / span > < span class = "subxComment" > # write out first-byte if necessary< / span >
< span id = "L920" class = "LineNr" > 920 < / span > 81 7/subop/compare %ebx 0xff/imm32
< span id = "L921" class = "LineNr" > 921 < / span > {
< span id = "L922" class = "LineNr" > 922 < / span > 7f/jump-if-> < span class = "Constant" > break< / span > /disp8
< span id = "L923" class = "LineNr" > 923 < / span > 89/< - %eax 3/r32/ebx
< span id = "L924" class = "LineNr" > 924 < / span > 66 ef/write-ax-into-port-dx
< span id = "L925" class = "LineNr" > 925 < / span > 49/decrement-ecx
< span id = "L926" class = "LineNr" > 926 < / span > 49/decrement-ecx
< span id = "L927" class = "LineNr" > 927 < / span > }
< span id = "L928" class = "LineNr" > 928 < / span > < span class = "subxComment" > # pad zeroes< / span >
< span id = "L929" class = "LineNr" > 929 < / span > 31/xor %eax 0/r32/eax
< span id = "L930" class = "LineNr" > 930 < / span > {
< span id = "L931" class = "LineNr" > 931 < / span > 81 7/subop/compare %ecx 0/imm32
< span id = "L932" class = "LineNr" > 932 < / span > 74/jump-if-= < span class = "Constant" > break< / span > /disp8
< span id = "L933" class = "LineNr" > 933 < / span > 66 ef/write-ax-into-port-dx
< span id = "L934" class = "LineNr" > 934 < / span > 49/decrement-ecx
< span id = "L935" class = "LineNr" > 935 < / span > 49/decrement-ecx
< span id = "L936" class = "LineNr" > 936 < / span > eb/jump < span class = "Constant" > loop< / span > /disp8
< span id = "L937" class = "LineNr" > 937 < / span > }
< span id = "L938" class = "LineNr" > 938 < / span > < span class = "Constant" > $store-first-sector-to-primary-bus-secondary-drive:end< / span > :
< span id = "L939" class = "LineNr" > 939 < / span > < span class = "subxS1Comment" > # . restore registers< / span >
< span id = "L940" class = "LineNr" > 940 < / span > 5b/pop-to-ebx
< span id = "L941" class = "LineNr" > 941 < / span > 5a/pop-to-edx
< span id = "L942" class = "LineNr" > 942 < / span > 59/pop-to-ecx
< span id = "L943" class = "LineNr" > 943 < / span > 58/pop-to-eax
< span id = "L944" class = "LineNr" > 944 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L945" class = "LineNr" > 945 < / span > 89/< - %esp 5/r32/ebp
< span id = "L946" class = "LineNr" > 946 < / span > 5d/pop-to-ebp
< span id = "L947" class = "LineNr" > 947 < / span > c3/return
< span id = "L948" class = "LineNr" > 948 < / span >
< span id = "L949" class = "Folded" > 949 < / span > < span class = "Folded" > +--241 lines: # disk helpers ------------------------------------------------------------------------------------------------------------------------------------------------------------< / span >
< span id = "L1190" class = "LineNr" > 1190 < / span >
< span id = "L1191" class = "LineNr" > 1191 < / span > < span class = "subxComment" > ## Controlling a PS/2 mouse< / span >
< span id = "L1192" class = "LineNr" > 1192 < / span > < span class = "subxComment" > # Uses no IRQs, just polling.< / span >
< span id = "L1193" class = "LineNr" > 1193 < / span > < span class = "subxComment" > # Thanks Dave Long: < a href = "https://github.com/jtauber/cleese/blob/master/necco/kernel/bochs/py8042.py" > https://github.com/jtauber/cleese/blob/master/necco/kernel/bochs/py8042.py< / a > < / span >
< span id = "L1194" class = "LineNr" > 1194 < / span > < span class = "subxComment" > #< / span >
< span id = "L1195" class = "LineNr" > 1195 < / span > < span class = "subxComment" > # Resources:< / span >
< span id = "L1196" class = "LineNr" > 1196 < / span > < span class = "subxComment" > # < a href = "https://wiki.osdev.org/Mouse_Input" > https://wiki.osdev.org/Mouse_Input< / a > < / span >
< span id = "L1197" class = "LineNr" > 1197 < / span >
< span id = "L1198" class = "LineNr" > 1198 < / span > < span class = "subxComment" > # results x/eax, y/ecx range from -256 to +255< / span >
< span id = "L1199" class = "LineNr" > 1199 < / span > < span class = "subxComment" > # See < a href = "https://wiki.osdev.org/index.php?title=Mouse_Input&oldid=25663#Format_of_First_3_Packet_Bytes" > https://wiki.osdev.org/index.php?title=Mouse_Input& oldid=25663#Format_of_First_3_Packet_Bytes< / a > < / span >
< span id = "L1200" class = "LineNr" > 1200 < / span > < span class = "subxFunction" > read-mouse-event< / span > : < span class = "subxComment" > # -> _/eax: int, _/ecx: int< / span >
< span id = "L1201" class = "LineNr" > 1201 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L1202" class = "LineNr" > 1202 < / span > 55/push-ebp
< span id = "L1203" class = "LineNr" > 1203 < / span > 89/< - %ebp 4/r32/esp
< span id = "L1204" class = "LineNr" > 1204 < / span > < span class = "subxS1Comment" > # . save registers< / span >
< span id = "L1205" class = "LineNr" > 1205 < / span > 52/push-edx
< span id = "L1206" class = "LineNr" > 1206 < / span > 53/push-ebx
< span id = "L1207" class = "LineNr" > 1207 < / span > < span class = "subxComment" > # if no event, return 0, 0< / span >
< span id = "L1208" class = "LineNr" > 1208 < / span > b8/copy-to-eax 0/imm32
< span id = "L1209" class = "LineNr" > 1209 < / span > b9/copy-to-ecx 0/imm32
< span id = "L1210" class = "LineNr" > 1210 < / span > (< a href = 'boot.subx.html#L1267' > any-mouse-event?< / a > ) < span class = "subxComment" > # => eax< / span >
< span id = "L1211" class = "LineNr" > 1211 < / span > 3d/compare-eax-and 0/imm32/false
< span id = "L1212" class = "LineNr" > 1212 < / span > 74/jump-if-= $read-mouse-event:end/disp8
< span id = "L1213" class = "LineNr" > 1213 < / span > < span class = "subxComment" > # var f1/edx: byte = inb(0x60)< / span >
< span id = "L1214" class = "LineNr" > 1214 < / span > 31/xor %eax 0/r32/eax
< span id = "L1215" class = "LineNr" > 1215 < / span > e4/read-port-into-al 0x60/imm8
< span id = "L1216" class = "LineNr" > 1216 < / span > 89/< - %edx 0/r32/eax
< span id = "L1217" class = "LineNr" > 1217 < / span > (< a href = 'boot.subx.html#L1252' > wait-for-mouse-event< / a > )
< span id = "L1218" class = "LineNr" > 1218 < / span > < span class = "subxComment" > # var dx/ebx: byte = inb(0x60)< / span >
< span id = "L1219" class = "LineNr" > 1219 < / span > 31/xor %eax 0/r32/eax
< span id = "L1220" class = "LineNr" > 1220 < / span > e4/read-port-into-al 0x60/imm8
< span id = "L1221" class = "LineNr" > 1221 < / span > 89/< - %ebx 0/r32/eax
< span id = "L1222" class = "LineNr" > 1222 < / span > (< a href = 'boot.subx.html#L1252' > wait-for-mouse-event< / a > )
< span id = "L1223" class = "LineNr" > 1223 < / span > < span class = "subxComment" > # var dy/ecx: byte = inb(0x60)< / span >
< span id = "L1224" class = "LineNr" > 1224 < / span > 31/xor %eax 0/r32/eax
< span id = "L1225" class = "LineNr" > 1225 < / span > e4/read-port-into-al 0x60/imm8
< span id = "L1226" class = "LineNr" > 1226 < / span > 89/< - %ecx 0/r32/eax
< span id = "L1227" class = "LineNr" > 1227 < / span > < span class = "subxComment" > # eax = dx< / span >
< span id = "L1228" class = "LineNr" > 1228 < / span > 89/< - %eax 3/r32/ebx
< span id = "L1229" class = "LineNr" > 1229 < / span > < span class = "subxComment" > # if (f1 & 0x10) dx = -dx< / span >
< span id = "L1230" class = "LineNr" > 1230 < / span > {
< span id = "L1231" class = "LineNr" > 1231 < / span > f6 0/subop/test-bits %dl 0x10/imm8
< span id = "L1232" class = "LineNr" > 1232 < / span > 74/jump-if-zero < span class = "Constant" > break< / span > /disp8
< span id = "L1233" class = "LineNr" > 1233 < / span > 0d/or-eax-with 0xffffff00/imm32
< span id = "L1234" class = "LineNr" > 1234 < / span > }
< span id = "L1235" class = "LineNr" > 1235 < / span > < span class = "subxComment" > # if (f1 & 0x20) dy = -dy< / span >
< span id = "L1236" class = "LineNr" > 1236 < / span > {
< span id = "L1237" class = "LineNr" > 1237 < / span > f6 0/subop/test-bits %dl 0x20/imm8
< span id = "L1238" class = "LineNr" > 1238 < / span > 74/jump-if-zero < span class = "Constant" > break< / span > /disp8
< span id = "L1239" class = "LineNr" > 1239 < / span > 81 1/subop/or %ecx 0xffffff00/imm32
< span id = "L1240" class = "LineNr" > 1240 < / span > }
< span id = "L1241" class = "LineNr" > 1241 < / span > < span class = "Constant" > $read-mouse-event:end< / span > :
< span id = "L1242" class = "LineNr" > 1242 < / span > < span class = "subxS1Comment" > # . restore registers< / span >
< span id = "L1243" class = "LineNr" > 1243 < / span > 5b/pop-to-ebx
< span id = "L1244" class = "LineNr" > 1244 < / span > 5a/pop-to-edx
< span id = "L1245" class = "LineNr" > 1245 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L1246" class = "LineNr" > 1246 < / span > 89/< - %esp 5/r32/ebp
< span id = "L1247" class = "LineNr" > 1247 < / span > 5d/pop-to-ebp
< span id = "L1248" class = "LineNr" > 1248 < / span > c3/return
< span id = "L1249" class = "LineNr" > 1249 < / span >
< span id = "L1250" class = "Folded" > 1250 < / span > < span class = "Folded" > +--152 lines: # mouse helpers -----------------------------------------------------------------------------------------------------------------------------------------------------------< / span >
< span id = "L1402" class = "LineNr" > 1402 < / span >
< span id = "L1403" class = "LineNr" > 1403 < / span > < span class = "subxComment" > # vim: ft=subx< / span >
2021-03-24 00:31:08 +00:00
< / pre >
< / body >
< / html >
<!-- vim: set foldmethod=manual : -->