diff options
Diffstat (limited to 'subx/ex5.subx')
| -rw-r--r-- | subx/ex5.subx | 39 |
1 files changed, 18 insertions, 21 deletions
diff --git a/subx/ex5.subx b/subx/ex5.subx index be7266a4..b74af463 100644 --- a/subx/ex5.subx +++ b/subx/ex5.subx @@ -5,47 +5,44 @@ # $ subx run ex5 == 0x08048054 # code segment, after leaving room for ELF header and segment headers -# opcode ModR/M SIB displacement immediate -# instruction mod, reg, Reg/Mem bits scale, index, base -# 1-3 bytes 0/1 byte 0/1 byte 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 0/1/2/4 bytes 0/1/2/4 bytes ## function main # prolog - 55 # push EBP - 89 e5 # copy ESP to EBP - # ModR/M: 11 (direct mode) 100 (src ESP) 101 (dest EBP) + 55 # push EBP + 89 3/mod/direct 5/rm32/EBP 4/r32/ESP # copy ESP to EBP # allocate x on the stack - 81 ec 4/imm32 # subtract 4 bytes from ESP - # ModR/M: 11 (direct mode) 101 (subtract imm32) 100 (dest EBP) + 81 5/subop/subtract 3/mod/direct 4/rm32/ESP 4/imm32 # subtract 4 bytes from ESP ## read(stdin, x, 1) # fd = 0 (stdin) - bb 0/imm32 # copy 0 to EBX + bb 0/imm32 # copy 0 to EBX # set location to read character to - 89 e9 # copy EBP to ECX - # ModR/M: 11 (direct mode) 101 (src EBP) 001 (dest ECX) + 89 3/mod/direct 1/rm32/ECX 5/r32/EBP # copy EBP to ECX # size = 1 character - ba 1/imm32 # copy 1 to EDX + ba 1/imm32 # copy 1 to EDX # syscall = read - b8 3/imm32 # copy 3 to EAX + b8 3/imm32 # copy 3 to EAX # call - cd 128/imm8 # int 80h + cd 0x80/imm8 # int 80h ## write(stdout, x, 1) # fd = 1 (stdout) - bb 1/imm32 # copy 1 to EBX + bb 1/imm32 # copy 1 to EBX # set location of character to write out - 89 e9 # copy EBP to ECX + 89 3/mod/direct 1/rm32/ECX 5/r32/EBP # copy EBP to ECX # ModR/M: 11 (direct mode) 101 (src EBP) 001 (dest ECX) # size = 1 character - ba 1/imm32 # copy 1 to EDX + ba 1/imm32 # copy 1 to EDX # syscall = write - b8 4/imm32 # copy 4 to EAX + b8 4/imm32 # copy 4 to EAX # call - cd 128/imm8 # int 80h + cd 0x80/imm8 # int 80h ## exit(EBX) - b8 1/imm32 # copy 1 to EAX - cd 128/imm8 # int 80h + b8 1/imm32 # copy 1 to EAX + cd 0x80/imm8 # int 80h # vim:ft=subx:nowrap |