User guide

; r0 now contains SWI number

CMP r0, #MaxSWI ; Rangecheck

LDRLS pc, [pc, r0, LSL#2] ; Jump to the appropriate routine.

B SWIOutOfRange

switable

DCD do_swi_1

DCD do_swi_2

do_swi_1

; Handle the SWI.

LDMFD sp!, {r0-r3,r12,pc}^ ; Restore the registers and return.

do_swi_2

Handling Processor Exceptions