diff options
Diffstat (limited to 'subx/050_write.subx')
| -rw-r--r-- | subx/050_write.subx | 64 |
1 files changed, 32 insertions, 32 deletions
diff --git a/subx/050_write.subx b/subx/050_write.subx index 8a65fc05..1975f7a3 100644 --- a/subx/050_write.subx +++ b/subx/050_write.subx @@ -1,45 +1,45 @@ # _write: write to a file descriptor == code -# instruction effective address operand displacement immediate -# op subop mod rm32 base index scale r32 -# 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 +# instruction effective address operand displacement immediate +# op subop mod rm32 base index scale r32 +# 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 # main: - # syscall(exit, 0) -- can't test _write just yet - bb/copy-to-EBX 0/imm32 - b8/copy-to-EAX 1/imm32 - cd/syscall 0x80/imm8 + # syscall(exit, 0) -- can't test _write just yet + bb/copy-to-EBX 0/imm32 + b8/copy-to-EAX 1/imm32 + cd/syscall 0x80/imm8 _write: # fd : int, s : (address array byte) -> <void> - # prolog - 55/push-EBP - 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP - # save registers - 50/push-EAX - 51/push-ECX - 52/push-EDX - 53/push-EBX - # syscall(write, fd, (data) s+4, (size) *s) + # prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # save registers + 50/push-EAX + 51/push-ECX + 52/push-EDX + 53/push-EBX + # syscall(write, fd, (data) s+4, (size) *s) # fd : EBX - 8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 3/r32/EBX 8/disp8 . # copy *(EBP+8) to EBX + 8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 3/r32/EBX 8/disp8 . # copy *(EBP+8) to EBX # data : ECX = s+4 - 8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 1/r32/ECX 0xc/disp8 . # copy *(EBP+12) to ECX - 81 0/subop/add 3/mod/direct 1/rm32/ECX . . . . . 4/imm32 # add to ECX + 8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 1/r32/ECX 0xc/disp8 . # copy *(EBP+12) to ECX + 81 0/subop/add 3/mod/direct 1/rm32/ECX . . . . . 4/imm32 # add to ECX # size : EDX = *s - 8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 2/r32/EDX 0xc/disp8 . # copy *(EBP+12) to EDX - 8b/copy 0/mod/indirect 2/rm32/EDX . . . 2/r32/EDX . . # copy *EDX to EDX + 8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 2/r32/EDX 0xc/disp8 . # copy *(EBP+12) to EDX + 8b/copy 0/mod/indirect 2/rm32/EDX . . . 2/r32/EDX . . # copy *EDX to EDX # syscall - b8/copy-to-EAX 4/imm32/write - cd/syscall 0x80/imm8 - # restore registers - 5b/pop-to-EBX - 5a/pop-to-EDX - 59/pop-to-ECX - 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 + b8/copy-to-EAX 4/imm32/write + cd/syscall 0x80/imm8 + # restore registers + 5b/pop-to-EBX + 5a/pop-to-EDX + 59/pop-to-ECX + 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 # vim:nowrap:textwidth=0 |