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| author | Kartik Agaram <vc@akkartik.com> | 2019-05-10 11:18:56 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-05-10 11:18:56 -0700 |
| commit | cdfb2dbfcf18cd2f23bf74199082392c3692a599 (patch) | |
| tree | 3b44482b3a9d1c1549e5679ede79c7f68cc1cc6d /subx | |
| parent | a1305217980a75ed5534daa7016a83f2d5602b43 (diff) | |
| download | mu-cdfb2dbfcf18cd2f23bf74199082392c3692a599.tar.gz | |
5150 - change interface for 'new-segment'
Tests still failing. Passing until layer 53.
Diffstat (limited to 'subx')
| -rw-r--r-- | subx/053new-segment.subx | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/subx/053new-segment.subx b/subx/053new-segment.subx index 21837628..83c890ea 100644 --- a/subx/053new-segment.subx +++ b/subx/053new-segment.subx @@ -17,39 +17,54 @@ # . 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 Entry: # manual test - # EAX = new-segment(0x1000) + # var ad/ECX : (address allocation-descriptor) = {0, 0} + 68/push 0/imm32/limit + 68/push 0/imm32/curr + 89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX + # new-segment(0x1000, ad) # . . push args + 51/push-ECX 68/push 0x1000/imm32 # . . call e8/call new-segment/disp32 # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP - + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # EAX = ad->curr + 8b/copy 0/mod/indirect 1/rm32/ECX . . . 0/r32/EAX . . # copy *ECX to EAX # write to *EAX to check that we have access to the newly-allocated segment c7 0/subop/copy 0/mod/direct 0/rm32/EAX . . . . . 0x34/imm32 # copy to *EAX - # syscall(exit, EAX) 89/copy 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to EBX b8/copy-to-EAX 1/imm32/exit cd/syscall 0x80/imm8 -new-segment: # len : int -> address +new-segment: # len : int, ad : (address allocation-descriptor) # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # . save registers + 50/push-EAX 53/push-EBX # copy len to _mmap-new-segment->len - # TODO: compute _mmap-new-segment+4 before runtime 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 0/r32/EAX 8/disp8 . # copy *(EBP+8) to EAX - bb/copy-to-EBX _mmap-new-segment/imm32 - 89/copy 1/mod/*+disp8 3/rm32/EBX . . . 0/r32/EAX 4/disp8 . # copy EAX to *(EBX+4) + 89/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX _mmap-new-segment:len/disp32 # copy EAX to *_mmap-new-segment:len # mmap(_mmap-new-segment) bb/copy-to-EBX _mmap-new-segment/imm32 b8/copy-to-EAX 0x5a/imm32/mmap cd/syscall 0x80/imm8 + # copy {EAX, EAX+len} to *ad + # . EBX = ad + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 3/r32/EBX 0xc/disp8 . # copy *(EBP+12) to EBX + # . *EBX = EAX + 89/copy 0/mod/indirect 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to *EBX + # . *(EBX+4) = EAX+len + 03/add 1/mod/*+disp8 5/rm32/EBP . . . 0/r32/EAX 8/disp8 . # add *(EBP+8) to EAX + 89/copy 1/mod/*+disp8 3/rm32/EBX . . . 0/r32/EAX 4/disp8 . # copy EAX to *(EBX+4) $new-segment:end: - # . epilog + # . restore registers 5b/pop-to-EBX + 58/pop-to-EAX + # . epilog 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP 5d/pop-to-EBP c3/return @@ -60,6 +75,7 @@ $new-segment:end: _mmap-new-segment: # type mmap_arg_struct # addr 0/imm32 +_mmap-new-segment:len: # len 0/imm32 # protection flags |