🚚 Moves from gnu assembler to netwide assembler

build.sh

@@ -2,6 +2,6 @@
 
 gcc main.c -o a.out
 
-gcc -c main.s -o b.o
+nasm -f elf64 main.s -o b.o
 ld b.o -o b.out
 rm b.o

main.s

@@ -1,18 +1,38 @@
-.global	_start
+SYS_EXIT equ 0x1
+SYS_READ equ 0x3
+SYS_WRITE equ 0x4
+
+STDIN equ 0x0
+STDOUT equ 0x1
+STDERR equ 0x2
+
+section .data
+	inputMsg db "> ", 0x0
+	inputLen equ $ - inputMsg
+
+section .bss
+	char resb 1
+	exitCode resb 1
+
+section .text
+	global _start
 
-.text
 _start:
-	mov $1, %rax
+	mov r8, 0
-	mov $1, %rdi
+	mov [exitCode], r8
-	mov $msg, %rsi
-	mov $len, %rdx
-	syscall
 
-	mov $60, %rax
+	mov rax, SYS_READ
-	mov $0, %rdi
+	mov rbx, STDIN
-	syscall
+	mov rcx, input
+	mov rdx, 64
+	int 0x80
 
-.data
+	;mov rax, SYS_WRITE
-msg:
+	;mov rbx, STDOUT
-	.ascii "Hello, world!\n"
+	;mov rcx, inputMsg
-	len = . - msg
+	;mov rdx, inputLen
+	;int 0x80
+
+	mov rax, SYS_EXIT
+	mov rbx, [exitCode]
+	int 0x80