Dear all,
working on a port of u-boot for mcf5307 i have found a major issue due
to an "errata" of this chip:
from MCF5307ER pdf:
35 Corrupted Return PC in Exception Stack Frame
35.1 Description
When processing an autovectored interrupt an error can occur that causes
0xFFFFFFFF to be written as
the return PC value in the exception stack frame. The problem is caused
by a conflict between an internal
autovector access and a chip select mapped to the IACK address space
(0xFFFFXXXX).
35.2 Workaround
. Set the C/I bit in the chip select mask register (CSMR) for the
chip select that is mapped to
0xFFFFXXXX. This will prevent the chip select from asserting
for IACK accesses.
. Remap the chip select to a different address range.
. Use external logic to provide external vectors for all
interrupts instead of autovectoring.
MASKS: 0H55J, 1H55J, 1J20C, 2J20C01/22/04
From time to time, in my mcf5307 board (uClinux + main line kernel), i
get the following trap exception, and since the calltrace pass always
from an interrupt, and i am getting the same trap i was getting in
u-boot, i am suspecting that the issue is the same.
~ # *** ILLEGAL INSTRUCTION *** FORMAT=4
Current process id is 0
BAD KERNEL TRAP: 00000000
PC: [<0002e500>]
SR: 2714 SP: 001bdf40 a2: 0016148c
d0: 00000000 d1: 00e80000 d2: 0000001e d3: 00000000
d4: 00000000 d5: 00ffd440 a0: 001bd000 a1: 001ab0e8
Process swapper (pid: 0, stackpage=001ac0e8)
Stack from 001bdf74:
000207a0 00ffdb94 00000000 00022ec6 0000001e 001bdf8c 00e80000
00ffdb94
00000000 00000000 00ffd440 001bd008 001ab0e8 0016148c 00000000
ffffffff
00000000 40782000 000208d8 00020a08 00020a0e 001608e4 001ab0e8
001ca5f8
001ca708 001be944 00000d6d 00000d6d 001cc000 00ffdb08 00ed8abc
00ffbf00
001ca86c 00ed8708 000200d8
Call Trace with CONFIG_FRAME_POINTER disabled:
[000207a0] do_IRQ+0x1e/0x5a
[00022ec6] inthandler+0x6a/0x74
[0016148c] schedule+0x0/0x30e
[000208d8] default_idle+0x22/0x40
[00020a08] cpu_idle+0x1a/0x20
[00020a0e] kernel_thread+0x0/0x3c
[001608e4] rest_init+0x6c/0x72
[001ca5f8] _einittext+0x0/0x0
[001be944] start_kernel+0x274/0x280
[000200d8] _exit+0x0/0x8
Disabling lock debugging due to kernel taint
Kernel panic - not syncing: Attempted to kill the idle task!
Stack from 001bdddc:
001bdf34 00029ae0 001961e6 001cc297 001cc297 00000400 001963cd
001bde24
00000001 001ab0e8 0000000b 00000000 001bd000 001bdf40 000d1d10
001bde24
0002ca90 001963cd 00000004 00000000 00000000 00ffd440 00000000
00ee8b76
0002a0a2 001bdf40 000d1d10 0002a0a2 001bdf34 00196170 00000004
00022656
0000000b 00000007 00000000 001bdf74 0019546c 001ab2ac 00000000
001ac0e8
001bdf40 0002a0a2 000226fe 001954f3 001bdf40 00000000 001954d6
00000000
Call Trace with CONFIG_FRAME_POINTER disabled:
[00029ae0] panic+0x60/0x1be
[001961e6] __func__.34039+0x201d2/0x34c70
[001963cd] __func__.34039+0x203b9/0x34c70
[000d1d10] strlen+0x0/0x1a
[0002ca90] do_exit+0x648/0x6cc
[001963cd] __func__.34039+0x203b9/0x3
[0002a0a2] printk+0x0/0x1c
[000d1d10] strlen+0x0/0x1a
[0002a0a2] printk+0x0/0x1c
[00196170] __func__.34039+0x2015c/0x34c70
[00022656] die_if_kernel+0xd4/0xda
[0019546c] __func__.34039+0x1f458/0x34c70
[0002a0a2] printk+0x0/0x1c
[000226fe] bad_super_trap+0xa2/0xb0
[001954f3] __func__.34039+0x1f4df/0x34c70
[001954d6] __func__.34039+0x1f4c2/0x34c70
[0016148c] schedule+0x0/0x30e
[0002278a] trap_c+0x30/0x3da
[00026c88] wake_up_process+0x0/0x16
[0002a0a2] printk+0x0/0x1c
[0002a0a2] printk+0x0/0x1c
[00026c88] wake_up_process+0x0/0x16
[00032d4a] update_process_times+0x40/0x4a
[0003277c] run_timer_softirq+0x14/0x234
[0004b00a] rcu_bh_qs+0x0/0x18
[00020598] trap+0x5c/0x64
[0016148c] schedule+0x0/0x30e
[0002e500] irq_enter+0x2e/0x3a
[000207a0] do_IRQ+0x1e/0x5a
[00022ec6] inthandler+0x6a/0x74
[0016148c] schedule+0x0/0x30e
[000208d8] default_idle+0x22/0x40
[00020a08] cpu_idle+0x1a/0x20
[00020a0e] kernel_thread+0x0/0x3c
[001608e4] rest_init+0x6c/0x72
[001ca5f8] _einittext+0x0/0x0
[001be944] start_kernel+0x274/0x280
[000200d8] _exit+0x0/0x8
Anyone have experienced something like this ?
Any help is appreciated, anyway i am going ahead in investigations
inside the kernel and let you know.
Regards,
angelo
_______________________________________________
uClinux-dev mailing list
uClinux-dev@uclinux.org
http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
This message was resent by uclinux-dev@uclinux.org
To unsubscribe see:
http://mailman.uclinux.org/mailman/options/uclinux-dev
