Red SOS and 15 Blinks on M404

Firmware Device OS
1

Hi everyone,

I recently flashed some updated firmware to an M404 after upgrading to Device OS 6.3.3 and immediately get red blinking SOS and 15 blinks (security error). Not sure how to go about debugging this or what a security error really means. I’m going to try going back to Device OS 5.9.0 and try flashing the same firmware and see if that makes a difference. In the meantime, please let me know what else I should try.

2

Looks like it works with Device OS 5.9.0 but has the security error with Device OS 6.3.3

3

Secure fault occurs when code attempts to access secure RAM. This typically occurs when you have an invalid pointer or other corrupted data that causes the wrong address to be accessed. Since it happens immediately at boot, the first place I would check is global object constructors. Because the order of object construction in C++ is not defined, just recompiling software with what seem to be innocuous changes can cause the order to be changed, which can expose a problem.

4

Got it. I may have found the issue then. I later found a pointer that was not properly initialized, but I haven’t tested this out on Device OS 6.3.3 yet.