Detecting warm and cold boot from qnx with i386 ?

QNX DEVELOPERS Realtime and Embedded
1

How to detect with qnx that an i386 compatible board has been reseted ? That is, implementing a way to know if the computer has been cold booted, or not.

I understand that a technique consists in writing a magic number in a given memory position, and check if this number is here when the application starts, before to write the magic number. I am not able to apply this technique to Qnx.

I have also tested to read the RESET_FLAG bios register, at the 0x472 memory address, with no success.

Are this solutions possible in the Qnx 6.3SP2 environment, or should I try another ones ??

Best regards,

Julián

2

Finally I have succeeded in having a “signature string” in the ram, using something like:

registro_bios2=(unsigned short *)mmap64(0, 2, PROT_READ|PROT_WRITE|PROT_NOCACHE, MAP_PHYS|MAP_SHARED, NOFD, MEMORY_TRACE_ADDRESS );

Note that this does not work using MAP_PRIVATE instead of MAP_SHARED, because then it seems that Qnx wash the memory area when the process finish.

3

Note that finally it was not possible to do it this way, because the watchdog reset provoqued a cleaning of the ram. So I had to use a persitence mechanism (writting a timestamp into a file).