Enabling watchdog/ BIOS function calls

QNX DEVELOPERS Realtime and Embedded
1

I need to enable a watchdog for two different SBCs running QNX 6.3. One of the boards requires me to call BIOS function 17h and the other one requires me to call function 15h. The functions need to be called with parameters to fill in some register values as well.

As I undestand it, BIOS function calls is a DOS concept. Are there fixed memory addresses that I can use to access these function? Otherwise how would I go about doing this?

2

You can’t really call BIOS fonctions. Best is to find the specification of the hardware and setup the hardware yourself

3

hi,

it’s possible to call bios functions - show in the qnx help for
_intr_v86() for more information - here is a simple example from me:

memset(&pcreg,0,sizeof(pcreg));
// ax=7700 ==> read HWIB EEPROM on board
pcreg.eax = 0x7700;
// address within eeprom
pcreg.edx = 0x300;
// do it (INT 15)					error = _intr_v86(0x15,&pcreg,NULL,0);
if (error != 0)				 	{
  // error ...
}
else
{
// ok read pcreg.ebx value ...				}

this example reads one byte from the onboard HWIP eeprom - if available! in the qnx help there is an vga and pci example

bye
matthias