compiling the startup file:
arm-none-eabi-as -o startup.o startup.s

linking .o file:
arm-none-eabi-ld -o first-hang.elf startup.o

convert the ELF to a raw binary dump
arm-none-eabi-objcopy -O binary first-hang.elf first-hang.bin

Blastoff:
qemu-system-arm -M vexpress-a9 -m 32M -no-reboot -nographic -monitor telnet:127.0.0.1:1234,server,nowait -kernel first-hang.bin

Telenet:
telnet localhost 1234

Helpfull tools for visual code:
hexdump -> right click on .bin file and show hexdump 