blob: 91bccce0264620ce6cba2a374e45f4a716e4b772 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
<!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 - subx/053new-segment.subx</title>
<meta name="Generator" content="Vim/8.0">
<meta name="plugin-version" content="vim7.4_v2">
<meta name="syntax" content="none">
<meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal-light">
<style type="text/css">
<!--
pre { 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; }
.subxComment { color: #005faf; }
.subxS2Comment { color: #8a8a8a; }
.subxMinorFunction { color: #875f5f; }
.LineNr { }
.subxS1Comment { color: #0000af; }
.SpecialChar { color: #d70000; }
.subxFunction { color: #af5f00; text-decoration: underline; }
.Constant { color: #008787; }
.Normal { color: #000000; background-color: #c6c6c6; padding-bottom: 1px; }
-->
</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;
}
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/master/subx/053new-segment.subx'>https://github.com/akkartik/mu/blob/master/subx/053new-segment.subx</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Create a new segment (pool of memory for allocating chunks from) in the form</span>
<span id="L2" class="LineNr"> 2 </span><span class="subxComment"># of an *allocation descriptor* that can be passed to the memory allocator</span>
<span id="L3" class="LineNr"> 3 </span><span class="subxComment"># (defined in a later layer).</span>
<span id="L4" class="LineNr"> 4 </span><span class="subxComment">#</span>
<span id="L5" class="LineNr"> 5 </span><span class="subxComment"># Currently an allocation descriptor consists of just the bounds of the pool of</span>
<span id="L6" class="LineNr"> 6 </span><span class="subxComment"># available memory:</span>
<span id="L7" class="LineNr"> 7 </span><span class="subxComment">#</span>
<span id="L8" class="LineNr"> 8 </span><span class="subxComment"># curr : address</span>
<span id="L9" class="LineNr"> 9 </span><span class="subxComment"># end : address</span>
<span id="L10" class="LineNr">10 </span><span class="subxComment">#</span>
<span id="L11" class="LineNr">11 </span><span class="subxComment"># This isn't enough information to reclaim individual allocations. We can't</span>
<span id="L12" class="LineNr">12 </span><span class="subxComment"># support arbitrary reclamation yet.</span>
<span id="L13" class="LineNr">13 </span>
<span id="L14" class="LineNr">14 </span>== code
<span id="L15" class="LineNr">15 </span><span class="subxComment"># instruction effective address register displacement immediate</span>
<span id="L16" class="LineNr">16 </span><span class="subxS1Comment"># . op subop mod rm32 base index scale r32</span>
<span id="L17" class="LineNr">17 </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="L18" class="LineNr">18 </span>
<span id="L19" class="LineNr">19 </span><span class="SpecialChar">Entry</span>: <span class="subxComment"># manual test</span>
<span id="L20" class="LineNr">20 </span> <span class="subxComment"># var ad/ECX : (address allocation-descriptor) = {0, 0}</span>
<span id="L21" class="LineNr">21 </span> 68/push 0/imm32/limit
<span id="L22" class="LineNr">22 </span> 68/push 0/imm32/curr
<span id="L23" class="LineNr">23 </span> 89/copy 3/mod/direct 1/rm32/ECX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ESP to ECX</span>
<span id="L24" class="LineNr">24 </span> <span class="subxComment"># new-segment(0x1000, ad)</span>
<span id="L25" class="LineNr">25 </span> <span class="subxS2Comment"># . . push args</span>
<span id="L26" class="LineNr">26 </span> 51/push-ECX
<span id="L27" class="LineNr">27 </span> 68/push 0x1000/imm32
<span id="L28" class="LineNr">28 </span> <span class="subxS2Comment"># . . call</span>
<span id="L29" class="LineNr">29 </span> e8/call <a href='053new-segment.subx.html#L41'>new-segment</a>/disp32
<span id="L30" class="LineNr">30 </span> <span class="subxS2Comment"># . . discard args</span>
<span id="L31" class="LineNr">31 </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="L32" class="LineNr">32 </span> <span class="subxComment"># EAX = ad->curr</span>
<span id="L33" class="LineNr">33 </span> 8b/copy 0/mod/indirect 1/rm32/ECX <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 *ECX to EAX</span>
<span id="L34" class="LineNr">34 </span> <span class="subxComment"># write to *EAX to check that we have access to the newly-allocated segment</span>
<span id="L35" class="LineNr">35 </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="L36" class="LineNr">36 </span> <span class="subxComment"># syscall(exit, EAX)</span>
<span id="L37" class="LineNr">37 </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="L38" class="LineNr">38 </span> b8/copy-to-EAX 1/imm32/exit
<span id="L39" class="LineNr">39 </span> cd/syscall 0x80/imm8
<span id="L40" class="LineNr">40 </span>
<span id="L41" class="LineNr">41 </span><span class="subxFunction">new-segment</span>: <span class="subxComment"># len : int, ad : (address allocation-descriptor)</span>
<span id="L42" class="LineNr">42 </span> <span class="subxS1Comment"># . prolog</span>
<span id="L43" class="LineNr">43 </span> 55/push-EBP
<span id="L44" class="LineNr">44 </span> 89/copy 3/mod/direct 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ESP to EBP</span>
<span id="L45" class="LineNr">45 </span> <span class="subxS1Comment"># . save registers</span>
<span id="L46" class="LineNr">46 </span> 50/push-EAX
<span id="L47" class="LineNr">47 </span> 53/push-EBX
<span id="L48" class="LineNr">48 </span> <span class="subxComment"># copy len to _mmap-new-segment->len</span>
<span id="L49" class="LineNr">49 </span> 8b/copy 1/mod/*+disp8 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/EAX 8/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(EBP+8) to EAX</span>
<span id="L50" class="LineNr">50 </span> 89/copy 0/mod/indirect 5/rm32/.disp32 <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/EAX <a href='053new-segment.subx.html#L75'>_mmap-new-segment</a>:len/disp32 <span class="subxComment"># copy EAX to *_mmap-new-segment:len</span>
<span id="L51" class="LineNr">51 </span> <span class="subxComment"># mmap(_mmap-new-segment)</span>
<span id="L52" class="LineNr">52 </span> bb/copy-to-EBX <a href='053new-segment.subx.html#L75'>_mmap-new-segment</a>/imm32
<span id="L53" class="LineNr">53 </span> b8/copy-to-EAX 0x5a/imm32/mmap
<span id="L54" class="LineNr">54 </span> cd/syscall 0x80/imm8
<span id="L55" class="LineNr">55 </span> <span class="subxComment"># copy {EAX, EAX+len} to *ad</span>
<span id="L56" class="LineNr">56 </span> <span class="subxS1Comment"># . EBX = ad</span>
<span id="L57" class="LineNr">57 </span> 8b/copy 1/mod/*+disp8 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 3/r32/EBX 0xc/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(EBP+12) to EBX</span>
<span id="L58" class="LineNr">58 </span> <span class="subxS1Comment"># . *EBX = EAX</span>
<span id="L59" class="LineNr">59 </span> 89/copy 0/mod/indirect 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="L60" class="LineNr">60 </span> <span class="subxS1Comment"># . *(EBX+4) = EAX+len</span>
<span id="L61" class="LineNr">61 </span> 03/add 1/mod/*+disp8 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/EAX 8/disp8 <span class="Normal"> . </span> <span class="subxComment"># add *(EBP+8) to EAX</span>
<span id="L62" class="LineNr">62 </span> 89/copy 1/mod/*+disp8 3/rm32/EBX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/EAX 4/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy EAX to *(EBX+4)</span>
<span id="L63" class="LineNr">63 </span><span class="Constant">$new-segment:end</span>:
<span id="L64" class="LineNr">64 </span> <span class="subxS1Comment"># . restore registers</span>
<span id="L65" class="LineNr">65 </span> 5b/pop-to-EBX
<span id="L66" class="LineNr">66 </span> 58/pop-to-EAX
<span id="L67" class="LineNr">67 </span> <span class="subxS1Comment"># . epilog</span>
<span id="L68" class="LineNr">68 </span> 89/copy 3/mod/direct 4/rm32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 5/r32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy EBP to ESP</span>
<span id="L69" class="LineNr">69 </span> 5d/pop-to-EBP
<span id="L70" class="LineNr">70 </span> c3/return
<span id="L71" class="LineNr">71 </span>
<span id="L72" class="LineNr">72 </span>== data
<span id="L73" class="LineNr">73 </span>
<span id="L74" class="LineNr">74 </span><span class="subxComment"># various constants used here were found in the Linux sources (search for file mman-common.h)</span>
<span id="L75" class="LineNr">75 </span><span class="subxMinorFunction">_mmap-new-segment</span>: <span class="subxComment"># type mmap_arg_struct</span>
<span id="L76" class="LineNr">76 </span> <span class="subxComment"># addr</span>
<span id="L77" class="LineNr">77 </span> 0/imm32
<span id="L78" class="LineNr">78 </span><span class="subxMinorFunction">_mmap-new-segment:len</span>:
<span id="L79" class="LineNr">79 </span> <span class="subxComment"># len</span>
<span id="L80" class="LineNr">80 </span> 0/imm32
<span id="L81" class="LineNr">81 </span> <span class="subxComment"># protection flags</span>
<span id="L82" class="LineNr">82 </span> 3/imm32 <span class="subxComment"># PROT_READ | PROT_WRITE</span>
<span id="L83" class="LineNr">83 </span> <span class="subxComment"># sharing flags</span>
<span id="L84" class="LineNr">84 </span> 0x22/imm32 <span class="subxComment"># MAP_PRIVATE | MAP_ANONYMOUS</span>
<span id="L85" class="LineNr">85 </span> <span class="subxComment"># fd</span>
<span id="L86" class="LineNr">86 </span> -1/imm32 <span class="subxComment"># since MAP_ANONYMOUS is specified</span>
<span id="L87" class="LineNr">87 </span> <span class="subxComment"># offset</span>
<span id="L88" class="LineNr">88 </span> 0/imm32 <span class="subxComment"># since MAP_ANONYMOUS is specified</span>
<span id="L89" class="LineNr">89 </span>
<span id="L90" class="LineNr">90 </span><span class="subxS2Comment"># . . vim:nowrap:textwidth=0</span>
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->
|