reading a bogus address in u-boot gives:
=> md 0x88000000
88000000:Machine check in kernel mode.
Caused by (from msr): regs 0ff0ec28 Unknown values in msr
NIP: 0000111C XER: 2000005F LR: 0FFDB104 REGS: 0ff0ec28 TRAP: 0200 DAR: 00000000
MSR: 00001000 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 00
GPR00: 0FFDB104 0FF0ED18 0FF0EF48 0FFE9DAC 00000002 00000010 FFFFFFFF 00000030
GPR08: 00000001 00000020 00000000 00000009 0FF0E828 1001910C 0FFF9000 0FFE9E10
GPR16: 0FFE9DAC 0FFEADF8 0FFEADF0 0FFEDCE4 48024028 8800002B 88000000 88000000
GPR24: 0FF0ED20 00000040 00000000 00000004 0FF0ED20 00000004 0FFFA650 88000000
Call backtrace:
0FFDB104 0FFC67B4 0FFCF668 0FFCED70 0FFCEEE0 0FFD1AA8 0FFB5FF4
0FFB2644
machine check
Resetting the board.
U-Boot 2008.10 (Oct 16 2009 - 14:57:46) MPC83XX, version=0x00910161
Reset Status: Software Hard, External/Internal Soft, External/Internal Hard
doing the same in linux kernel gives an immediate reboot (checkstop):
# readmm 32 88000000 1
U-Boot 2008.10 (Oct 16 2009 - 14:57:46) MPC83XX, version=0x00910161
Reset Status: Check Stop, External/Internal Soft, External/Internal Hard
We're using an MPC8313E on a custom board (similar to MPC8313E-RDB) with
U-Boot v2008.10 and linux 2.6.28.
The problem is that the linux kernel exception handler
(arch/powerpc/kernel/head_32.S)
doesn't work. It looks like this:
. = 0x200
0x200 mtspr SPRN_SPRG0,r10
mtspr SPRN_SPRG1,r11
mfcr r10
#define EXCEPTION_PROLOG_1 \
0x20c mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
andi. r11,r11,MSR_PR; \
tophys(r11,r1); /* use tophys(r1) if kernel */ \
beq 1f; \
mfspr r11,SPRN_SPRG3; \
lwz r11,THREAD_INFO-THREAD(r11); \
addi r11,r11,THREAD_SIZE; \
tophys(r11,r11); \
1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
#define EXCEPTION_PROLOG_2 \
CLR_TOP32(r11); \
0x230 stw r10,_CCR(r11); /* save registers */ \
stw r12,GPR12(r11); \
stw r9,GPR9(r11); \
mfspr r10,SPRN_SPRG0; \
stw r10,GPR10(r11); \
mfspr r12,SPRN_SPRG1; \
stw r12,GPR11(r11); \
mflr r10; \
stw r10,_LINK(r11); \
mfspr r12,SPRN_SRR0; \
mfspr r9,SPRN_SRR1; \
stw r1,GPR1(r11); \
stw r1,0(r11); \
tovirt(r1,r11); /* set new kernel sp */ \
li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
MTMSRD(r10); /* (except for mach check in rtas) */ \
stw r0,GPR0(r11); \
lis r10,stack_frame_regs_mar...@ha; /* exception frame marker */ \
0x278 addi r10,r10,stack_frame_regs_mar...@l; \
stw r10,8(r11); \
SAVE_4GPRS(3, r11); \
SAVE_2GPRS(7, r11)
0x298 addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x200, machine_check_exception)
0x29c li r10,trap
...
bl machine_check_exception
somehow machine_check_exception isn't reached. can anyone tell me why ?
is there something wrong with EXCEPTION_PROLOG_1/EXCEPTION_PROLOG_2 ?
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
