CS641 MIPS Cross compiler setup and first example 1/31/11

Edit your .profile file to add /usr/local/bin/mips to your PATH, and define cs641

PATH=:/usr/local/bin:/usr/local/bin/mips:/usr/ucb:/bin:/usr/bin:$HOME/bin:.

^^^^^^^^^^^^^^^^^^^ added

export PATH

cs641=/courses/cs641/public_html ; export cs641

hello1.c: Hello-world in C with string in data section

extern int printf(char *s, ...); <--to avoid #include <stdio.h>

char msg[] = "Hello, world!";

int main()

{

printf("%s", msg); This compiles and runs on Linux

}

sf06.cs.umb.edu$ mips-gcc -S hello1.c <--compile to assembler for MIPS

sf06.cs.umb.edu$ more hello1.s <-- look at resulting .s file

.file 1 "hello1.c" <-- ignore all directives except

.section .mdebug.abi32 <-- .data, .text, .ascii, .globl

.previous

.abicalls

.globl msg

.data

.align 2

.type msg, @object

.size msg, 14

msg:

.ascii "Hello, world!\000"

.rdata

.align 2

$LC0:

.ascii "%s\000"

.text

.align 2

.globl main

.ent main

.type main, @function

main:

.frame $fp,32,$31 # vars= 0, regs= 2/0, args= 16, gp= 8

.mask 0xc0000000,-4

.fmask 0x00000000,0

.set noreorder

.cpload $25

.set reorder

addiu $sp,$sp,-32 <-- we’ll tackle this soon, ignore for now

sw $31,28($sp)

sw $fp,24($sp)

move $fp,$sp

.cprestore 16

The code that loads a0 and a1 and calls printf

la $4,$LC0

la $5,msg

jal printf

move $sp,$fp

lw $31,28($sp)

lw $fp,24($sp)

addiu $sp,$sp,32

j $31

.end main

.ident "GCC: (GNU) 3.4.5"