Permalink
Switch branches/tags
Nothing to show
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
126 lines (118 sloc) 2.02 KB
global _start
%define True 1
%define False 0
%define r1 rax
%define r2 rcx
%define r3 rdx
%define r5 rbp
%define stdin 0
%define stdout 1
%macro pushdata 1
push r1
push r5
mov r5, [data_stack_length]
;; In case we want to do this with a constant or address
mov r1, %1
mov [data_stack + 8*r5], r1
inc qword [data_stack_length]
pop r5
pop r1
%endmacro
%macro popdata 1
push r5
dec qword [data_stack_length]
mov r5, [data_stack_length]
mov %1, [data_stack + 8*r5]
pop r5
%endmacro
%macro prints 1+
jmp %%endstr
%%str: db %1
%%endstr:
mov eax, 1
mov rdi, stdout
lea rsi, [%%str]
mov rdx, %%endstr-%%str
syscall
%endmacro
_start:
prints "Hello world"
call printeol
prints "1000 in hex and reversed is: "
pushdata 1000
call print
call printeol
pushdata 2000
pushdata 3000
popdata r1
call print
pushdata r1
call print
mov eax, 60
mov rdi, 0
syscall
print:
;; Print value at the top of the stack as an integer in hex.
;; Callable without losing register values
push qword rax
push qword rcx
push qword rdx
push qword rbx
push qword rbp
push qword rsi
push qword rdi
;; x = data_stack.pop()
popdata r3
mov r1, 8
dec r1
.loop8times:
;; sys.print(stdout, print_chars[x & 1111b], 1)
mov r2, r3
and r2, 1111b
push qword r1
push qword r3
mov eax, 1
mov rdi, stdout
lea rsi, [print_chars + 1*r2]
mov rdx, 1
syscall
pop r3
pop r1
;; x >>= 4
shr r3, 4
dec r1
jns .loop8times
mov eax, 1
mov rdi, stdout
lea rsi, [space]
mov rdx, 1
syscall
pop rdi
pop rsi
pop rbp
pop rbx
pop rdx
pop rcx
pop rax
ret
printeol:
mov eax, 1
mov rdi, stdout
lea rsi, [eol]
mov rdx, 1
syscall
ret
printspace:
mov eax, 1
mov rdi, stdout
lea rsi, [space]
mov rdx, 1
syscall
ret
section .data
eol: db 10
space: db 32
print_chars: db "0123456789abcdef"
section .bss
data_stack_length: resq 1
data_stack: resq 10000