Subject: IRQ lock problem

From: David Aparicio Campos <[email-masked]>
Date: Wed, 19 Jul 2000 10:59:08 +0200

Hello all:

I'm developing some firmware code to run Linux on a SA110 (with
FootBridge) based
board. At this stage, I have downloaded an "vmlinux" image (e.g, a
decompressed one)
at address 0x00000000. (Entry point is at 0x00008000, right?). I have
not been lucky
when I download a "zImage", I'm not sure where in memory should I load
it.
When I call Linux, it says:

***************
call 0x8000
boot no options
Linux version 2.2.13-rmk2 (root@lobos) (gcc version 2.95.1 19990816
(release)) #4 Tue Jul 18 09:16:54 CEST 2000
Calibrating delay loop... <3>IRQ LOCK: IRQ7 is locking the system,
disabled
IRQ LOCK: IRQ7 is locking the system, disabled
IRQ LOCK: IRQ7 is locking the system, disabled
(...infinite loop, same message again and again...)
***************

Anybody can tell me any clue about what should I check?. I guess I have
left some hardware misconfigured, but I run out of ideas. What is the
meaning
of this message?. From linux source code, I guess it's something about
interrupt handler calling itself. Am I right? Is IRQ7 related to a
"PC compatible" architecture, e.g a parallel port or something like
this,
or is it related to a StrongArm architecture (IRQ 7 is TIMER4, I guess)?

I'm not very used to "arch/arm/kernel/*"... :-)
Is there any "literature" about specific Linux/ARM internals? I'm afraid

I could be asking something written somewhere...

I have "borrowed" boot.s from Compaq bootldr project (thank you Jamey &
George for your help!). I configure PCI bus, download a kernel and jump
to it (I guess MMU is disabled as it is ICACHE and DCACHE).

Some lines about my hardware environment:
Interrupts disabled at firmware level, I poll status registers instead,
but maybe I have not written every register, so I have left some
hardware
(specially for southbridge) in a unknown state. My motherboard is a
CATS,
I have revised specific inicialization in kernel, it writes some
registers
but it seems fine.
No hardware attached (no NIC, IDE or whatever). I download everything
throught footbridge serial line. Motherboard has a SA110, a 21285 and
a ALi1543 southbridge. This last one has all hardware disabled (USB,
keyboard, mouse, IDE serial ports...) as far as I know.

Thank you very much!

  David Aparicio