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implement segment section in compute-offsets

This commit is contained in:
nc 2019-07-04 12:18:18 -04:00
parent c015791e80
commit f80a025e52
1 changed files with 112 additions and 3 deletions
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115
subx/apps/survey.subx
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@ -541,7 +541,7 @@ $compute-offsets:label:
# . . push args
68/push 0x10/imm32/row-size
52/push-EDX
ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12)
ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16)
# . . call
e8/call get-or-insert/disp32
# . . discard args
@ -567,7 +567,6 @@ $compute-offsets:label:
# continue
0f 84/jump-if-equal $compute-offsets:word-loop/disp32
$compute-offsets:segment:
# TODO: implement the rest of this block
# if slice-equal?(word-slice/EDX, "==")
# . EAX = slice-equal?(word-slice/EDX, "==")
68/push "=="/imm32
@ -578,14 +577,110 @@ $compute-offsets:segment:
# . EAX == 0 ?
3d/compare-EAX-and 0/imm32
# . if so, goto else
74/jump-if-equal $compute-offsets:else/disp8
0f 84/jump-if-equal $compute-offsets:else/disp32
# . or fallthrough
# seg/EAX = get-or-insert(segments, curr-segment-name, row-size=16)
# . push args
68/push 0x10/imm32/row-size
68/push compute-offsets:curr-segment-name/imm32
ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12)
# . call
e8/call get-or-insert/disp32
# . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# seg->size/EBX = file-offset - seg->starting-offset
# . save ECX
51/push-ECX
# . EBX = *file-offset
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX compute-offsets:file-offset/disp32 # copy *file-offset to EBX
# . ECX = seg->starting-offset
8b/copy 1/mod/*+disp8 0/rm32/EAX . . . 1/r32/EBX 4/disp8 . # copy *(EAX+4) to ECX
# . EBX -= ECX
29/subtract 3/mod/direct 3/rm32/EBX . . . 1/r32/ECX . . # subtract ECX from EBX
# . seg->size = EBX
89/copy 1/mod/*+disp8 0/rm32/EAX . . . 3/r32/EBX 8/disp8 . # copy EBX to *(EAX+8)
# . restore ECX
59/pop-to-ECX
# trace-slsns("segment '", curr-segment-name, "' has size 0x", seg->size/EBX, "")
# . push args
68/push "segment '"/imm32
68/push compute-offsets:curr-segment-name/imm32
68/push "' has size 0x"/imm32
53/push-EBX
68/push ""/imm32
# . call
e8/call trace-slsns/disp32
# . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x14/imm32 # add to ESP
# next-word(line/ECX, curr-segment-name)
68/push compute-offsets:curr-segment-name/imm32
51/push-ECX
e8/call next-word/disp32
# . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# if slice-empty?(curr-segment-name) abort
# . EAX = slice-empty?(curr-segment-name)
68/push compute-offsets:curr-segment-name/imm32
e8/call slice-empty?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# . EAX == 1 ?
3d/compare-EAX-and 1/imm32
# . if so, abort
0f 84/jump-if-equal $compute-offsets:abort/disp32
# segment-start/EBX = {0, 0}
68/push 0/imm32
68/push 0/imm32
89/copy 3/mod/direct 3/rm32/EBX . . . 4/r32/ESP . . # copy ESP to EBX
# next-word(line/ECX, segment-start/EBX)
53/push-EBX
51/push-ECX
e8/call next-word/disp32
# . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# if slice-empty?(segment-start/EBX) abort
# . EAX = slice-empty?(segment-start/EBX)
53/push-EBX
e8/call slice-empty?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# . EAX == 1 ?
3d/compare-EAX-and 1/imm32
# . if so, abort
0f 84/jump-if-equal $compute-offsets:abort/disp32
# save segment-start/EBX (and prep for parse-hex-int call)
53/push-EBX
# seg/EBX = get-or-insert(segments, curr-segment-name, row-size=16)
# . push args
68/push 0x10/imm32/row-size
68/push compute-offsets:curr-segment-name/imm32
ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12)
# . EBX = EAX
89/copy 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to EBX
# seg->address = parse-hex-int(segment-start (already on stack))
# . EAX = parse-hex-int(segment-start)
e8/call parse-hex-int/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# . seg->address = EAX
89/copy 0/mod/indirect 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to *EBX
# seg->file-offset = *file-offset/EAX
# . EAX = *file-offset
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX compute-offsets:file-offset/disp32 # copy *file-offset to EAX
89/copy 1/mod/*+disp8 3/rm32/EBX . . . 0/r32/EAX 4/disp8 . # copy EAX to *(EBX+4)
# trace-slsns("segment '", curr-segment-name, "' has size 0x", seg->size/EBX, "")
# . push args
68/push "segment '"/imm32
68/push compute-offsets:curr-segment-name/imm32
68/push "' is at file offset size 0x"/imm32
53/push-EAX
68/push ""/imm32
# . call
e8/call trace-slsns/disp32
# . discard args
# segment-offset = 0
c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . compute-offsets:segment-offset/disp32 0/imm32 # copy to *segment-offset
eb/jump $compute-offsets:line-loop:break/disp8
$compute-offsets:else:
# width/EAX = compute-width(word-slice/EDX)
52/push-EDX
@ -619,6 +714,20 @@ $compute-offsets:end:
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
$compute-offsets:abort:
# . _write(2/stderr, error)
# . . push args
68/push "'==' must be followed by segment name and segment-start\n"/imm32
68/push 2/imm32/stderr
# . . call
e8/call _write/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# . syscall(exit, 1)
bb/copy-to-EBX 1/imm32
b8/copy-to-EAX 1/imm32/exit
cd/syscall 0x80/imm8
# never gets here
test-compute-offsets:
# input: