blob: 46cf045ba616a23a24fd4d3dda5873d5ffc11fc4 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
# Print out a (global variable) string to stdout.
#
# To run:
# $ ./translate_subx 000init.subx apps/ex6.subx
# $ ./a.elf
# Hello, world!
== code
# . 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
Entry:
# write(stdout, X, Size)
# . fd = 1 (stdout)
bb/copy-to-ebx 1/imm32
# . initialize X (location to write result to)
b9/copy-to-ecx X/imm32
# . initialize Size
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 2/r32/edx Size/disp32 . # copy *Size to edx
# . syscall
e8/call syscall_write/disp32
# exit(ebx)
e8/call syscall_exit/disp32
== data
Size: # size of string
0x0d/imm32 # 13
X: # string to print
48 65 6c 6c 6f 20 77 6f 72 6c 64 21 0a 00
# H e l l o ␣ w o r l d ! newline null
# . . vim:nowrap:textwidth=0
|