Re: NetBSD/sgimips 10.0 RELEASE on SGI Challenge S: INSTALL32_IP2x works, GENERIC32_IP2x kernel panics on boot after install

[Tim McIntosh <tmcintos%eskimo.com@localhost>]

> On May 20, 2024, at 6:36 PM, Tim McIntosh <tmcintos%eskimo.com@localhost> wrote:
> 
>> What I would do in your position is:
>> - setup netboot - IIRC it's really just bootp/dhcp, load kernel via tftp, mount root via nfs.
>> - build an INSTALL32_IP2x kernel, try to netboot it
>> - INSTALL* is just GENERIC* with a bunch of 'no *' statements to strip
>> it down. Enable a few of them, try again. If my theory is correct it
>> should start crashing when the kernel image hits a certain size
>> - you probably don't want all the stuff disabled in INSTALL32_IP2x, if
>> you get to an image that's small enough to work and contains what you
>> need, I'd run with that for the time being.

I don’t have a viable netboot environment currently, but what I was able to do to transfer files to the local disk was boot the installation image and then use FTP to transfer files via a temporary Python-based FTP server running on my development machine. Tedious, but it works.

So I built a modified INSTALL32_IP2x kernel with the following changes:

> --- a/sys/arch/sgimips/conf/INSTALL32_IP2x
> +++ b/sys/arch/sgimips/conf/INSTALL32_IP2x
> @@ -8,11 +8,11 @@ include       "arch/sgimips/conf/GENERIC32_IP2x"
>  makeoptions    COPTS="-Os -mmemcpy"
>    # Enable the hooks used for initializing the root memory-disk.
> -options         MEMORY_DISK_HOOKS
> -options         MEMORY_DISK_IS_ROOT     # force root on memory disk
> -options         MEMORY_DISK_SERVER=0    # no userspace memory disk support
> -options         MEMORY_DISK_ROOT_SIZE=6600 # size of memory disk in blocks (3300k)
> -options         MEMORY_DISK_RBFLAGS=RB_SINGLE   # boot in single-user mode
> +#options         MEMORY_DISK_HOOKS
> +#options         MEMORY_DISK_IS_ROOT     # force root on memory disk
> +#options         MEMORY_DISK_SERVER=0    # no userspace memory disk support
> +#options         MEMORY_DISK_ROOT_SIZE=6600 # size of memory disk in blocks (3300k)
> +#options         MEMORY_DISK_RBFLAGS=RB_SINGLE   # boot in single-user mode
>    # shrink kernel since ARC BIOS seems to have 8MB limit
>  options        FFS_NO_SNAPSHOT

I tried loading the ELF debug version and it appears to panic in the same way:

> >> boot
> 
> NetBSD/sgimips 10.0 Bootstrap, Revision 1.5 (Thu Mar 28 08:33:33 UTC 2024)
> 
> devopen: scsi(0)disk(3)rdisk(0)partition(0) type scsi file netbsd.gdb
> 3446288+113248 [243344+233661]=0x3d9e04
> 
> Exception: <vector=UTLB Miss>
> Status register: 0x2<IPL=8,MODE=KERNEL,EXL>
> Cause register: 0x30008008<CE=3,IP8,EXC=RMISS>
> Exception PC: 0x0, Exception RA: 0x881eadb4
> exception, bad address: 0x0
>   Saved user regs in hex (&gpda 0xa8740e48, &_regs 0xa8741048):
>   arg: a8740000 0 5f 10
>   tmp: a8740000 883c0000 388c 1 88400d44 8832c15c 883bb960 1fae
>   sve: a8740000 0 0 0 0 0 0 0
>   t8 a8740000 t9 0 at 0 v0 0 v1 0 k1 883b0000
>   gp a8740000 fp 0 sp 0 ra 0
> 
> PANIC: Unexpected exception
> 
> [Press reset or ENTER to restart.]

I’ll have to try the ECOFF variant and attempt debugging when I get some more time to investigate this.

Thanks,
Tim