diff options
Diffstat (limited to 'subx/ex4.subx')
| -rw-r--r-- | subx/ex4.subx | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/subx/ex4.subx b/subx/ex4.subx new file mode 100644 index 00000000..98b9f55a --- /dev/null +++ b/subx/ex4.subx @@ -0,0 +1,23 @@ +## read a character from stdin + +# 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 +# 0: e_entry = 0x08048054 + ## read(1, x, 1) + # fd = 1 + bb 1/imm32 # copy 1 to EBX + # set location to write to + b9 00 80 04 08 # copy 0x08040000 to ECX + # size = 1 character + ba 1/imm32 # copy 1 to EDX + # syscall = read + b8 3/imm32 # copy 3 to EAX + # call + cd 128/imm8 # int 80h + + ## exit(EBX) + b8 1/imm32 # copy 1 to EAX + cd 128/imm8 # int 80h + +# vim:ft=subx:nowrap |