Hello I'm trying to run the program assembled from this code:
Quote.data
test_string byte "hello sailor", 0
.code
ExitProcess proto dwExitCode:dword
OutputDebugStringA proto lpOutputString:qword
main proc
mov rax, -1
mov rax, -2
mov rax, -3
mov rax, -4
lea rcx, test_string
call OutputDebugStringA
mov rcx, 0
call ExitProcess
main endp
end
but I get an access violation when I call OutputDebugStringA, any ideas why?
> any ideas why ?
No Win64 stack frame.
Could you point me where to learn about fixing it?
Hello vik,
.data
test_string db 'Hello world!', 0
.code
EXTERN ExitProcess:PROC
EXTERN OutputDebugStringA:PROC
OutputDebugString TEXTEQU <OutputDebugStringA>
main PROC
sub rsp,4*8+8
mov rax,-1
mov rax,-2
mov rax,-3
mov rax,-4
lea rcx,test_string
call OutputDebugString
xor rcx,rcx
call ExitProcess
main ENDP
END
Moving to Windows Vista x64 :
https://www.codeproject.com/Articles/17263/Moving-to-Windows-Vista-x64
Thank you. I ended up figuring out that I was missing shadow space.
What's the difference between declaring external functions with
label PROC
and
EXTERN label
Label :
QuoteCreates a new label by assigning the current location-counter value and the given qualifiedType to name.
https://docs.microsoft.com/en-us/cpp/assembler/masm/label-masm?view=msvc-160
Extern :
QuoteDefines one or more external variables, labels, or symbols called name whose type is type.
https://docs.microsoft.com/en-us/cpp/assembler/masm/extern-masm?view=msvc-160