Linux 184.108.40.206 PowerPC 750FX Initialization Failures (Caching & MMU)
bgoodman at empirix.com
Fri Jul 29 07:11:01 EST 2005
I am running the 220.127.116.11 Kernel with a Force CPCI-695 board.
(This board has a PPC 750FX, with a Marvell Disco II (MV64360) - although it uses a 8250, instead of the Disco II UART.)
This thing is hanging like a buffalo on bootup - in early Kernel initialization:
I setup_common_caches it gets to here:
mfspr r11,SPRN_HID0 ← HID0 is 0x800200a4
bne 1f /* don't invalidate the D-cache */
ori r8,r8,HID0_DCI /* unless it wasn't enabled */
mtspr SPRN_HID0,r8 /* enable and invalidate caches */ ← r8 is now 0x8002cca4
### NEVER GETS HERE
mtspr SPRN_HID0,r11 /* enable caches */
So it's hanging trying to enable and invalidate the caches.
So - trying to ditch that problem until later - I had it leave the caches off and continuing.
Now, it gets to the point where it tries to enable the MMU, and in the turn_on_mmu function it appears to go unresponsive right after the return-from-interrupt:
lis r0,start_here at h
ori r0,r0,start_here at l
## GETS HERE
RFI /* enables MMU */
I put a check in start_here - and it never reaches it. The BATs should all be set up per-normal initialization, and I verified that it was mapping Physical address 0 to Effective Address 0xc0000000 - but still no luck.
BTW - I am loading my znetboot image (zImage with no ELF header) at 0x800000 - so it's not relocating on startup (and verified that this was happening correctly.)
I don't know if the caching issue is related to the MMU issue - or they are two totally separate things.
bgoodman -et- empirix -dut- com
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