trap: cpu0, TLB miss (load or instr. fetch) in kernel mode

[Rajasekhar Pulluru <pullururajasekhar%gmail.com@localhost>]

Dear group members,

Need your help.

While porting usb driver to evbmips, receive below trap during system
bootup. Couldn't see backtrace as program counter is 0. how to proceed
debugging.

pid 0(system): trap: cpu0, TLB miss (load or instr. fetch) in kernel mode
status=0x8203, cause=0x108, epc=0, vaddr=0xdeadbeef
tf=0x85011d20 ksp=0x85011e60 ra=0xffffffff80272a88 ppl=0x17108128
kernel: TLB miss (load or instr. fetch) trap
Stopped in pid 0.4 (system) at  0:      invalid address.
db> show reg
at          0xffffffc0
v0          0
v1          0x82        _KERNEL_OPT_NLOOP+0x1
a0          0
a1          0x1 _KERNEL_OPT_NINET
a2          0x8 _KERNEL_OPT_NINET+0x7
a3          0x812782a0  cpu_info_store
a4          0x2 _KERNEL_OPT_NINET+0x1
a5          0x1 _KERNEL_OPT_NINET
a6          0x80        _KERNEL_OPT_DDB_HISTORY_SIZE+0x1c
a7          0x81e794f8  ipl_eimr_map+0x18
t0          0x82a8a000  _prop_data_pool+0x5ea58
t1          0x1 _KERNEL_OPT_NINET
t2          0x85010000
t3          0x8027bfd4  tc_init+0x13c
s0          0xd13dc000
s1          0xd13dc008
s2          0x93f347e0
s3          0x1 _KERNEL_OPT_NINET
s4          0
s5          0x8c1cf970
s6          0
s7          0x8c1cfb0e
t8          0x93f347e0
t9          0
k0          0xb127da63
k1          0x392d9417
gp          0x823931d0  idstate+0x7e70
sp          0x85011e60
fp          0xea        _KERNEL_OPT_NLOOP+0x69
ra          0x80272a88  softint_dispatch+0x80
sr          0x8203      _KERNEL_OPT_MEMORY_DISK_ROOT_SIZE+0x2203
mdlo        0xaf31dc46
mdhi        0x343d000
bad         0x8018ce4
cs          0x108       _KERNEL_OPT_NLOOP+0x87
pc          0
0:      invalid address.
db>