Emulate ARM x32 architecture

2 min readMay 20, 2021

This is a guide step by step to compile and debug ARM x32 code with other CPU architecture on Linux.

Install some GNU and Linux tools:

$ sudo apt-get update && sudo apt-get upgrade -y
$ sudo apt-get install build-essential

Compilers for each ARM architecture

ARM X32

$ sudo apt-get install gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf

Install other tool for executing and debugging:

$ sudo apt-get install qemu qemu-user qemu-user-static

Degub:

$ sudo apt-get install gdb-multiarch

Example ARM x32 :

create a file called hello_armx32.s

$ vim hello_armx32.s

Assemble and Link

$ arm-linux-gnueabihf-as -g hello_armx32.s -o hello_armx32.o

Note: don’t forget flag -g for debugging

$ arm-linux-gnueabihf-ld hello_armx32.o -o hello_armx32

execute:

./hello_armx32

qemu-arm ./hello_armx32

Debugging:

We go to use qemu-arm and gdb-multiarch for debugging program because ARM processor use different registers and qemu helps to emulate them.

First step:

Create a gdb server with qemu and its port with this command:

$ qemu-arm -g 1234 ./hello_armx32

Note: you can use another number for the port but it must be the same in gdb-multiarch.

It waits for response. Then, start gdb-multiarch with next commands:

$ gdb-multiarch -q — nh -ex ‘set architecture arm’ -ex ‘file hello_arm32’ -ex ‘target remote :1234’ -ex ‘layout split’ -ex ‘layout regs’

Note: You can remove some flags used for gdb-multiarch like layout split or layout regs but never -ex ‘target remote : 1234’ it binds with qemu port.

start to debug :

(gdb)b _start

Note: dont use gdb command: run

(gdb) next

Note: gdb uses normal commands for debugging.

That’s all. Now to learn to program in ARM x32