The SCB->SHCSR is written during boot, when enabling faults. This overwrites the SYSACT bit that was set by branching to Handler_Mode earlier. The integrity checks on exception return fails because the IPSR and the active interrupt in the SCB don't match.
Fixes: (1) enables the faults before, or (2) do not modify other bits in SCB->SHCSR than the fault enabling bits.
bmarcot
commented
8 years ago
The
SCB->SHCSRis written during boot, when enabling faults. This overwrites theSYSACTbit that was set by branching to Handler_Mode earlier. The integrity checks on exception return fails because theIPSRand the active interrupt in the SCB don't match.Fixes: (1) enables the faults before, or (2) do not modify other bits in
SCB->SHCSRthan the fault enabling bits.Seen on NRF52 eval board, but not in QEMU.