Running binary file with qemu

Question

I am learning arm assembly language in my one course. I am having little problem in getting started. I have written a simple c code:

int main()
{
    int a = 10;
    int b = 20;
    int c = a+b;
}

And then I converted it to assembly code using gnu arm by giving the command:

arm-elf-gcc -S first.c

This generated a file first.s containing assembly code:

    .file   "first.c"
    .text
    .align  2
    .global main
    .type   main, %function
main:
    @ args = 0, pretend = 0, frame = 12
    @ frame_needed = 1, uses_anonymous_args = 0
    mov ip, sp
    stmfd   sp!, {fp, ip, lr, pc}
    sub fp, ip, #4
    sub sp, sp, #12
    mov r3, #10
    str r3, [fp, #-16]
    mov r3, #20
    str r3, [fp, #-20]
    ldr r2, [fp, #-16]
    ldr r3, [fp, #-20]
    add r3, r2, r3
    str r3, [fp, #-24]
    mov r0, r3
    sub sp, fp, #12
    ldmfd   sp, {fp, sp, pc}
    .size   main, .-main
    .ident  "GCC: (GNU) 3.4.3"

Then I compiled the assembly code using following command:

arm-elf-gcc -g first.s

This generated a.out binary file. Then I tried to run a.out with qemu using command:

qemu-arm a.out

But this generates output

Segmentation fault

I can't find the mistake, what am I doing wrong?

Answer 1

You are trying to run qemu in user mode. You also need to link the libraries which corresponds to arm.

take a look at the script files in below pkg.

http://wiki.qemu.org/download/linux-user-test-0.3.tar.gz

You will need to run qemu -L library_PATH_ARM ./a.out