RE: mpc8xx-2.2.13 booting problem

Alan,

After another 5 hours of debugging, I've narrowed the problem to the
decrement counter interrupt. For some unknown reasons, the interrupt never
gets clear. The system just keep looping and waiting for this interrupt to
be cleared.

In the file time.c (this is the file where all of the timer interrupt code
is), it mentions something about making an assumption that MBX board is
running off a 32.768KHz crystal. But the Touchstone board has a 3.57 MHz
crystal. So, something has to be changed to make this work! Anyone has any
ideas???

BTW, the network bootloader is modified from a comercial OS. We use it to
jump start our project. I don't think we can share the code with everyone,
sorry...

Regards
Clinton Lam

-----Original Message-----
From: Alan Mimms [mailto:alan@packetengines.com]
Sent: Thursday, February 03, 2000 10:03 AM
To: Clinton Lam; Linuxppc-Embedded (E-mail)
Subject: Re: mpc8xx-2.2.13 booting problem


Clinton,

This function enables interrupts.  Some bit of hardware is leaving an
interrupt asserted permanently, or else your port or your
driver for some bit
of hardware is not turning off the interrupt request by
servicing the interrupt
properly.  Or, possibly, your 8xx interrupt management is screwed up.

One of those explanations is it, just about guaranteed...

Luck.
a

On Thu, 03 Feb 2000, Clinton Lam wrote:

quoted

Hi,

I am new to the embeded linux. I am trying to port

mpc8xx-2.2.13 kernel to

quoted

our custom board, called Touchstone. It is a reference

design based on

quoted

mpc823, which has 32 Mbyte of SDRAM, and 4 Mbyte of flash.

So far, I've developed a network bootloader, which

downloads the zImage to

quoted

the target. I am at the stage where I can unzip the kernel

image to address

quoted

location 0x0, and jump to it. Then, inside the routine

"start_kernel", I am

quoted

able to get the console up and have the linux banner

partially displayed at

quoted

the cosole.

However, after some more kernel initialization in

"start_kernel", the

quoted

program stuck in a routine called "sti()". I've debugged

through this

quoted

routine (it is an assembly routine) , and it seems that it

is looping

quoted

forever inside the routine. I know that the routine is

trying to set the EE

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bit in MSR, and also doing some thing with

ppc_n_lost_interrupts, which I

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don't quite understand.

Does anyone have any idea what is wrong with my port? Can

someone explain to

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me what is the purpose of this "sti()" routine, what are

the possible cause

quoted

for it to hang?

Your response is greately appreciated!

Thanks in advance.

Clinton Lam

--
Alan Mimms     Packet Engines, Inc.     Spokane, Washington [99214-0497]
  USA, Earth, Sol, Milky Way, The Local Group, Virgo Supercluster, U0
Despite the cost of living, have you noticed how popular it remains?
  -- Steven Wright?

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