linux-kernel-module-cheat/baremetal/arch/arm/el.c

/* https://github.com/cirosantilli/linux-kernel-module-cheat#arm-exception-level */

#include <stdio.h>
#include <inttypes.h>

int main(void) {
	register uint32_t r0 __asm__ ("r0");
	__asm__ ("mrs r0, CPSR" : : : "%r0");
	printf("%" PRIu32 "\n", r0 & 0x1F);
	return 0;
}