Stefan Reinauer wrote:
Welcome back, Tyson!
Thanks! ...I guess. ;-)
On 1/29/10 9:08 PM, Tyson Sawyer wrote:
Hello,
A small voice from the distant past here.
I have a custom system using LinuxBIOS V1. Yes! 1! This is a
PIII/440BX based system.
We have found that we can boot 2.6.23-17, but can not boot 2.6.24.
Investigation using characters posted on the serial port suggest that
we are starting the kernel and getting to about the point where the
clock speed of the CPU and then it just stops as far as we can tell.
>
Could you provide a log of the boot with each kernel? It might help
getting an idea of what could be going wrong.
The kernel provides no output what at all. The early printk option also
provides nothing. It dies too early for that. I had the guy working on
it (I sent the email to coreboot because he just went on a week
vacation) put in some low level code to write directly to the serial
port (copied from the code I have in Linuxbios) so that we would have
some sort of output, even if just a single character.
We've found that if we put in more output to the serial port, it dies
earlier in the code. We can't be sure, bit it appears that it might be
some sort of a time based problem. It dies after a certain amount of
time and if we use that time by polling characters out the serial
port, then we don't get as far through the code before death.
>
How early in the code can you get it to die? I wonder whether some
watchdog driver could cause the trouble?
I don't think there are any, but I could look into that. The hardware
is our own that we've been using since I as previously involved with
Linuxbios and V1 was state of the art. There is no watchdog hardware,
but we could look for a driver that might do something silly? Seems
like a long shot, but worth a look.
One thought that almost fits the facts is that a interrupt might be
occurring and not handled properly. But it happens that the CPU clock
speed code disables interrupts and this is where it is dying.
Knowing a bit more about the hardware and kernel configuration would
certainly help.
I'm not sure where to start there, esp. since it is custom hardware
except to say that there is nothing exotic.
There seems to have been a number of changes in 2.6.24 to support
booting kernels in virtual machines and to merge ia64 and ia32 under
x86. Some notes were added about 32 bit boot loaders that reference
LinuxBIOS. However, we've been unable to find what it is that we are
doing wrong. We have grep'ed the internet and browsed through the
CoreBoot email archives, but failed to find anything that might have
been in either "place".
>
Worst case you could diff between 2.6.23-17 and 2.6.24 and do a binary
search over the differences until you find the culprit. But maybe there
is a higher level approach that wants to be taken first.
Yeah... that. I was hoping that the easy way out would be that I
mention 2.6.24 and everyone jumps up and down and tells me about the
well known change for 32 bit loaders that we need to make. ;-)
Best regards,
Stefan
Thanks!
Ty
--
Tyson D Sawyer iRobot Corporation
Lead Systems Engineer Government & Industrial Robotics
tsaw...@irobot.com Robots for the Real World
781-418-3329 http://www.irobot.com
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