first mips assembly

LAB

objective

• compile mips assembly with gcc
• run in emulation

setup

• gcc: aboriginal cross compiler , mipsel
• emulator: qemu-user-static

sudo apt-get install qemu-user-static

vim exit.S

#include <sys/regdef.h>

#include <asm/unistd.h>

.data

.text

.global main

main:

        .set noreorder

        .cpload t9

        .set reorder

        li a0, 99

        li v0, __NR_exit

        syscall

note: file ext must be capital S

compile

include cross gcc in path or point run directly

$mipsel-gcc -o exit exit.S

run

copy qemu to chroot folder

$cp $(which qemu-mipsel-static) .

$sudo chroot . ./qemu-mipsel-static ./exit

/lib/ld-uClibc.so.0: No such file or directory

we get error because we compile dynamicly and the lib folder not include in chroot folder

we need to bind the lib folder for outside the chroot to chroot location

$mkdir lib

$sudo mount --bind <path/to/cross_compile/lib> lib

$sudo chroot . ./qemu-mipsel-static ./exit

checking

echo $?

99 # the return value for exit syscall