[U-Boot-Users] Booting from 4MB flash on Walnut derived board

Brian S. Park brian at corelis.com
Fri Jun 27 04:44:20 CEST 2003

Hi all,
I have custom board built based on IBM walnut demo board.
It worked well when I was using 512KB flash. Since I want to burn all my 
application on the flash, I installed 4MB flash and u-boot no longer works.

According to README file, I should set CFG_FLASH_BASE, CFG_MONITOR_BASE and 
TEXT_BASE to the beginning of the flash. When I did this, the processor was 
not able to pick up the instruction on the beginning of the flash. Probably 
because the EBC is not configured to access 4MB of flash when it boots up.

Is there a way to make it come up with 4MB of flash? I'm using u-Boot 0.3.0

I tried changing the CFG_FLASH_BASE only but I get bus error when u-Boot 
tries to access the flash. I did setup pb0cr so that it can access 4MB 
address space.

U-Boot 0.3.0 (Jun 26 2003 - 19:43:08)

CPU:   IBM PowerPC 405GP Rev. E at 200 MHz (PLB=100, OPB=50, EBC=50 MHz)
            PCI sync clock at 100 MHz, external PCI arbiter enabled
            16 kB I-Cache 8 kB D-Cache
Board: ### No HW ID - assuming WALNUT405
I2C:   ready
DRAM:  128 MB
FLASH: Bus Fault @ 0x07fd2954, fixup 0x00000000
Machine check in kernel mode.
Caused by (from msr): regs 07fadd08 Machine check signal - probably due to 
mm ft
with mmu off
NIP: 07FD2954 XER: 00000000 LR: 07FD219C REGS: 07fadd08 TRAP: 0200 DAR: 
MSR: 00001000 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 00

GPR00: 00000090 07FADDF8 40000000 07FADE08 07FF1194 00000000 00000000 0110795E
GPR08: 07FD9C84 FFC00000 00000002 0000051C 28000004 00000000 07FEF300 08050000
GPR16: 00000000 00000000 00000000 00000000 00001000 07FADDF8 00000000 07FD219C
GPR24: 07FD2954 07FADF64 07FADF90 07FF1194 07FADF90 07FADF64 07FF0110 0000FFFF
Call backtrace:
machine check

Any help will be appreciated.

Thank you.


Brian S. Park  brian at corelis.com  (562) 926-6727 x143
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