6.4. MIPS Example

# hello.S	by Spencer T. Parkin

# This is my first MIPS-RISC assembly program!
# To compile this program type:
# > gcc -o hello hello.S -non_shared

# This program compiles without errors or warnings
# on a PlayStation2 MIPS R5900 (EE Core).
# EE stands for Emotion Engine...lame!

# The -non_shared option tells gcc that we`re
# not interrested in compiling relocatable code.
# If we were, we would need to follow the PIC-
# ABI calling conventions and other protocols.

#include <asm/regdef.h>		// ...for human readable register names
#include <asm/unistd.h>		// ...for system serivices			

		.rdata					# begin read-only data segment
		.align		2			# because of the way memory is built
hello:		.asciz		"Hello, world!\n"	# a null terminated string
		.align		4			# because of the way memory is built
length:		.word		. - hello		# length = IC - (hello-addr)
		.text					# begin code segment
		.globl		main			# for gcc/ld linking
		.ent		main			# for gdb debugging info.
main:		# We must specify -non_shared to gcc or we`ll need these 3 lines that fallow.
#		.set		noreorder		# disable instruction reordering
#		.cpload		t9			# PIC ABI crap (function prologue)
#		.set		reorder			# re-enable instruction reordering
		move		a0,$0			# load stdout fd
		la		a1,hello		# load string address
		lw		a2,length		# load string length
		li		v0,__NR_write		# specify system write service
		syscall					# call the kernel (write string)
		li		v0,0			# load return code
		j		ra			# return to caller
		.end		main			# for dgb debugging info.

# That`s all folks!