help me on 2.6.15 kernel on MPC850

From: gshan
Date: Thu Apr 12 2007 - 02:14:27 EST


Hey Guys,

The CPU was spinning when executing in head_8xx.S::initial_mmu. I have located the instruction that cause the spinning through on-board leds. Do you have any ideas?

#ifdef CONFIG_8xx_COPYBACK
mtspr SPRN_DC_CST, r8 <<< The spinning was caused by this instruction
#endif

#else
/*
* For a debug option, I left this here to easily enable
* the write through cache mode
*/
lis r8, DC_SFWT@h
mtspr SPRN_DC_CST, r8
lis r8, IDC_ENABLE@h
mtspr SPRN_DC_CST, r8
#endif

blr

-----------------------------

The output from u-boot:

=> tftp 0x100000 uImage
Using SCC ETHERNET device
TFTP from server 90.0.0.3; our IP address is 90.0.0.50
Filename 'uImage'.
Load address: 0x100000
Loading: #################################################################
#################################################################
###################################
done
Bytes transferred = 844738 (ce3c2 hex)
=> bootm
## Booting image at 00100000 ...
Image Name: Linux-2.6.15
Created: 2007-04-07 17:25:29 UTC
Image Type: PowerPC Linux Kernel Image (gzip compressed)
Data Size: 844674 Bytes = 824.9 kB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
Uncompressing Kernel Image ... OK <<< The CPU is spinning then

-----------------------------

The hardware, bootloader, linux I'm using:

1) MPC850, 1KB DCache + 2KB ICache
2) u-boot 1.1.4 ( Data Cache is turned off all the way, but instruction cache is always on)
3) ppclinux 2.6.15

Thanks,
Gavin

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