Oops, I have found the problem:)
The board I am testing with at the moment is one of the sis550 boards which has the RISE core in it (claimed by RISE marketing to be PII compatible) - I assumed the kernel config file in the Linuxbios kernel-patched directory for the 2.4.17 kernel for SiS would work - this is set up for a PII processor and there is obviously an instruction in the PII not implemented in the RISE core. I dropped it down to a 486 for starters, and it works fine. Thanks for the help Hamish > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of Eric W Biederman > Sent: 18 July 2002 06:15 > To: [EMAIL PROTECTED] > Cc: Ronald G Minnich; LinuxBIOS > Subject: Re: mkelfImage > > > "Hamish Guthrie \(Mail Lists\)" <[EMAIL PROTECTED]> writes: > > > Eric, > > > > I have a printk immediately after the lines of the patch > > > > #if 1 > > console_drivers = &minimal_serial_console; > > #endif > > printk("setup_arch\n"); > > > > The serial output I get from the kernel is: > > > > setup_arch > > Unknown interrupt > > Unknown interrupt > > .... > > > > I have looked at the PIC setup - no change - the IDT is the same... > > > > I am not sure where to look next > > Because it repeats and interrupts are disabled it is an exception, not > an interrupt so the PIC should not have an effect. > > After that the next thing the kernel does is to initialize the e820 > memory map, which should have printed. There is some > debug code you can enable in convert.c (from mkelfImage) that will > print this before the kernel loads could you have the kernel print > that out? > > With respect to your kernel, do you have any interesting patches applied, > and are you certain you are compiling for a 486? On the off chance > the problem is that an illegal instruction gets executed. > > Excecuting an explicit cli ``asm("cli");'' should guarantee that > it is an exception and not an interrupt happening. > > Something else you can do is instrument unknown interrupt to print > it's return address so you can see where the code is blowing up. > > Eric
