User guide

5.8 Prefetch Abort handler

If the system has no MMU, the Prefetch Abort handler can simply report the error and quit. Otherwise the address

that caused the abort must be restored into physical memory. lr_ABT points to the instruction at the address

following the one that caused the abort, so the address to be restored is at lr_ABT - 4. The virtual memory fault

for that address can be dealt with and the instruction fetch retried. The handler should therefore return to the same

instruction rather than the following one, for example:

SUBS pc,lr,#4

Handling Processor Exceptions