Comment 4 for bug 1216845

With the new 2.0 ARM semihosting ABI, there is an optional extension SYS_EXIT_EXTENDED which can be used to implement returning a non-zero exit code for 32-bit ARM programs:

https://developer.arm.com/docs/100863/latest/semihosting-operations/sys_exit_extended-0x20#sh-ext-exit-extended

QEMU should implement this.