I've the following implementation for a svc exception handler on a cortex-m0: int __attribute__((naked)) sv_call_handler(uint32_t n, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint32_t arg4, uint32_t arg5) { irq_off();When I built it for cortex-m0 it looks like this: 0x7a50 <sv_call_handler> movs r4, r0 0x7a52 <sv_call_handler+2> str r1, [r7, #12] 0x7a54 <sv_call_handler+4> str r2, [r7, #8] 0x7a56 <sv_call_handler+6> str r3, [r7, #4] 0x7a58 <sv_call_handler+8> bl 0x3194 <irq_off> Resulting in a hard fault because of course, the value in R7 is 'undefined' and there is a high chance that it contains a value that isn't within the address range.When I remove the naked attribute, the assembly makes much more sense: 0x7a50 <sv_call_handler> push {r4, r5, r7, lr} 0x7a52 <sv_call_handler+2> sub sp, #32 0x7a54 <sv_call_handler+4> add r7, sp, #8 0x7a56 <sv_call_handler+6> str r0, [r7, #12]I've used the naked attribute without issues before, so why does this happen now? Has it anything to do with the fact that the svc exception handler is a special case?