commented

1 files changed, 61 insertions, 0 deletions

diff --git a/prog3.asm b/prog3.asm
new file mode 100644
index 0000000..f5c0b7e
--- /dev/null
+++ b/prog3.asm
@@ -0,0 +1,61 @@
+;playing with the stack
+
+section .data
+arg	db	255
+
+section .text
+global _start
+
+uhh:
+	; save stack
+	push ebp
+	; create local stack
+	mov ebp, esp
+	; create "local" variable(s) by subtracting the stack by X bytes
+	sub ebp, 4
+
+	; first argument is 3 dwords (4 bytes * 3) in...
+	; copy first argument to eax
+	mov eax, [ebp+12]
+	
+	; mov eax (first arg) into local stack variable
+	mov [ebp-4], eax
+	; clear eax
+	mov eax, 0
+
+	; mov local variable into ebx 
+	mov ebx, [ebp-4]
+	
+	; reset stack pointer
+	; aka, giveth back what we taketh away
+	add ebp, 4
+
+	; restore stack
+	mov esp, ebp
+	pop ebp
+	ret
+
+_start:
+	; save stack
+	push ebp
+	mov ebp, esp
+
+	; push value of 'arg' to the stack from ebx
+	mov ebx, [arg]	
+	push ebx
+	; clear ebx
+	mov ebx, 0
+
+	call uhh
+	
+	; restore ebx (because I can.) should be value of 'arg'
+	pop ebx
+
+	; restore stack
+	mov esp, ebp
+	pop ebp
+
+	; exit program, ebx is return value
+	mov eax, 1
+	int 80h
+	ret