SS20 and SMP using Ross modules
I have here an SS20 which has run Woody reliably for an extended period. It has
2x Ross 625 CPUs, PROM 2.25R and 256Mb RAM.
It runs single-processor 2.4.27 from Sarge reliably, but attempting to boot SMP
gives an interrupt 15/watchdog error.
If it is given this sequence of commands:
reset
ross625
ibuf-off
2 switch-cpu
ibuf-off
0 switch-cpu
boot
it will boot into SMP, but eventually fails with a "wrong magic" error.
If the Ross modules are replaced by Suns then it will boot either single
processor or SMP successfully, and run reliably.
Reverting to Ross modules, if I build a standalone kernel I find it's too large
to boot from disc, but I can boot it over the LAN (boot net root=/dev/sda2) and
the system runs SMP reliably. However I notice that while the BogoMIPS rating of
a single CPU is 150 when running SMP it's dropped to 104 per processor- I
thought this was calibrated using a tight loop?
I'm assuming that none of the core developers will be looking at this because of
the age of the hardware, and I don't have the hardware information to even start
making sense of this sort of problem. However as a workaround can anybody point
me at the documentation that describes the Debian/SPARC-specific kernel rebuild
procedure- running the standard "make vmlinux" gives me a kernel image of around
2Mb.
My position is that I'm keen on promoting Sun kit for in-house use, but having
to boot over the LAN makes it difficult to argue that they are a viable
alternative to PCs, and if I'm not confident making that argument I'm not going
to put my neck on the block and ask for money for newer systems.
--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk
[Opinions above are the author's, not those of his employers or colleagues]
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