> > I am trying to write a userspace 'driver' for a hardware watchdog on an > > industrial PC (a Jumptec, to be precise). > > > > This watchdog is setup and controlled by executing an interrupt 21, > > service 0xe000 and 0xe001 to the BIOS interrupt service routine. > > > > I do not have to receive anything, 'just' to execute such interrupts, > > controlling the value of the ax, bx, cx and dx registers. It will run as > > root. It is not timing critical. > > > > Being a Linux newbie, I have not been able to find out how to do this. > > Standard assembler will not allow a direct "int $0x15", and I have not > > found anything in the syscalls indicating a possibility for such a thing. > > > > So my question is: What's the easiest way to do it? And where is that > > documented? > > Hmm, there are two choices, the 'easiest' is to go into vm86 mode and send the > interrupt there, but that is rather kludgie and probably not very efficiant, the > best way would be to just write the stuff yourself using io ports, i doubt that > it is so hard, as long as you can find specs for it. > Efficiency is not a problem if I can find an example I can cut-and-paste from. Unfortunately I do not have the specs for how to operate the watchdog using only IO ports - it has to be done through the &%€?$ interrupt. Henrik Østergaard ----------------------------------------------------------- Henrik Oestergaard Madsen Phone: +45 44 48 44 92 PhD, Research Engineer Cell: +45 29 99 95 03 Mosegard Park 42 email: Henrik@Ostergaard.net DK-3500 Vaerloese WWW homepage: Denmark http://www.Ostergaard.net/Henrik ----------------------------------------------------------- -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
