Linux boot fails after MMU (MPC8260)
Christian.Peter at ascom.ch
Christian.Peter at ascom.ch
Fri Jan 5 00:47:53 EST 2001
Hi
I try to boot linux 2.4.0test8 on a custom 8260 board. It fails to start the kernel (no output) and
i think it hangs somewhere after the mmu initialization (ppc/kernel/head.S).
My knowledge of the mmu and the 8260 is not very good, therefore i'm not sure!
A prior co-worker (unfortunately not in the company anymore) had successfully started the kernel
on a SBC8260 board with a vxworks bootloader and some patches for the mbxboot.
I have near the same configuration, some difference in the vxworks bootloader (chip-select, IMMR 0x0f00000), but
i set this new in mbxboot/head_8260.S to the following values.
Memory Map
----------
0x00000000 60x SDRAM
0x20000008 some LEDs
0xFE000000 Flash
IMMR 0xF0000000
Currently i'm debugging with 2 LEDs on the board and i can switch the LED's on and off until
the RFI. After RFI the code should jump to start_here, but it never gets there.
ppc/kernel/head.S
mfmsr r0
ori r0,r0,MSR_DR|MSR_IR
mtspr SRR1,r0
lis r0,start_here at h
ori r0,r0,start_here at l
mtspr SRR0,r0
SYNC
RFI /* enables MMU */
This is a extract of the terminal output.
TFTP_CLIENT...
Starting at 0x400000...
CPU/CPM/BUS: 165/132/66 Mhz
Ethernet (in decimal): 0:160:30:1:4:5
loaded at: 00400000 0040B274
board data at: 00FFFFC0 00FFFFEC
relocated to: 00200100 0020012C
zimage at: 0040B274 0047F33D
avail ram: 00480000 01000000
Linux/PPC load:
Uncompressing Linux...
done.
Now booting the kernel
Is this a configuration problem (memory map)? Any ideas or suggestions?
Many thanks in advance.
Chris
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