Unstable MPC8245 board

[William A. Gatliff]

Guys:


I'm trying to run a recent (two weeks ago, Makefile has 2.4.21-pre4)
MV kernel on a semi-custom MPC8245 board that looks a lot like a
Cogent CSB281.  I'm using binutils-2.13.1, gcc-3.2.1, uClibc-0.9.17,
busybox-0.60.4.  I'm also using the uMON bootloader from the CSB281.

The kernel boots up fine, and mounts an initial ramdisk (romfs-0.3.1)
containing a very minimal busybox environment.  After a few ls -lR's,
the system freezes hard.

According to my bdi2000, I usually end up in trap 700 before the CPU
halts.  But sometimes I get pretty decent oops messages first:

tulip_interrupt: ioaddr=c3000c00 tulip_debug=5
Oops: kernel access of bad area, sig: 11
NIP: C00F6EB4 XER: 20000000 LR: C00F7CE4 SP: C0117180 REGS: c01170d0 TRAP: 0300
   Not tainted
MSR: 00001032 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 11
DAR: 504067FC, DSISR: 20000000
TASK = c0115440[0] 'swapper' Last syscall: 120
last math c0902000 last altivec 00000000
GPR00: 00000004 C0117180 C0115440 504067FC FFFFFFFE C01052FD C0117220 0000000A
GPR08: 00000000 504067FC FFFFFFFF C01171B8 C0140000 00000000 305C8801 B80688E6
GPR16: D0040604 C3180200 00022412 00000000 00001032 00000000 00000000 00000019
GPR24: 00000400 C0144FB4 C0117220 FFFFFFFF 504067FC C01453B3 00000000 C0144FB4
Call backtrace:
C0015F94 C0015D0C C008DAB4 C0006F4C C0007010 C0005FAC C0007558
C000756C C0003B38 C01275DC 00003828
Kernel panic: Aiee, killing interrupt handler!
In interrupt handler - not syncing
 <0>Rebooting in 180 seconds..Initializing the MPC8245 PCI Bridge

(Yes, I also have problems without _any_ ethernet drivers installed).

The rest of the time, everything is simply scrambled by the time I
type HALT on the bdi.

I know what your answer will be, especially now that I've read the
mailing list archives over and over: "memory interface problem".  I
tend to agree--- it's my main theory at the moment, in fact.  I'm just
not sure what to do about it.  Some questions:

* Is there any reasonable explanation besides a memory problem?

* I see the checksum for the kernel's .text region changing at
runtime.  I'm pretty sure this isn't normal, is it?

* Does anyone have a working CSB281 kernel (or similar) that I could
borrow?  :^) Sandpoint won't get it, I don't have all the extra
hardware onboard (I think I look more like a Muenski).

* Can anyone suggest a really conservative memory interface setup to
test with?  The MPC8245 is a bit of a stretch for me at the moment...


Here's my .config.  For brevity, I omitted everything that's not set.

CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_HAVE_DEC_LOCK=y
CONFIG_EXPERIMENTAL=y
CONFIG_ADVANCED_OPTIONS=y
CONFIG_PPC=y
CONFIG_PPC32=y
CONFIG_6xx=y
CONFIG_PPC_STD_MMU=y
CONFIG_CSB281=y
CONFIG_PPC_ISATIMER=y
CONFIG_PCI=y
CONFIG_NET=y
CONFIG_SYSCTL=y
CONFIG_SYSVIPC=y
CONFIG_KCORE_ELF=y
CONFIG_BINFMT_ELF=y
CONFIG_KERNEL_ELF=y
CONFIG_BINFMT_MISC=y
CONFIG_PPC_RTC=y
CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="console=ttyS0,38400 root=/dev/ram"
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_SIZE=4096
CONFIG_BLK_DEV_INITRD=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_BOOTP=y
CONFIG_NET_ETHERNET=y
CONFIG_NET_PCI=y
CONFIG_PCNET32=y
CONFIG_TULIP=y
CONFIG_TULIP_MMIO=y
CONFIG_NATSEMI=y
CONFIG_NE2K_PCI=y
CONFIG_8139CP=y
CONFIG_SERIAL=y
CONFIG_SERIAL_CONSOLE=y
CONFIG_UNIX98_PTYS=y
CONFIG_UNIX98_PTY_COUNT=256
CONFIG_TMPFS=y
CONFIG_RAMFS=y
CONFIG_PROC_FS=y
CONFIG_DEVPTS_FS=y
CONFIG_ROMFS_FS=y
CONFIG_NFS_FS=y
CONFIG_ROOT_NFS=y
CONFIG_SUNRPC=y
CONFIG_LOCKD=y
CONFIG_MSDOS_PARTITION=y
CONFIG_DEBUG_KERNEL=y
CONFIG_BDI_SWITCH=y
CONFIG_MORE_COMPILE_OPTIONS=y
CONFIG_COMPILE_OPTIONS="-g -ggdb"




I'm stumped.  Thanks to _anyone_ who can help me make any progress on
this...




b.g.
--
Bill Gatliff
http://billgatliff.com

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