from armv7m.c:43
static const char * const armv7m_exception_strings[] = {
"", "Reset", "NMI", "HardFault",
"MemManage", "BusFault", "UsageFault", "SecureFault",
"RESERVED", "RESERVED", "RESERVED", "SVCall",
"DebugMonitor", "RESERVED", "PendSV", "SysTick"
};