>> The flat tree located at 0xbe4300 as the kerne message showed. Why >> cannot the kernel access this area? No TLB set for this area? >> >> <1>Unable to handle kernel paging request for data at address 0xc0be4308 >> <1>Faulting instruction address: 0xc01fdabc >> <4>Oops: Kernel access of bad area, sig: 11 [#1] > > Before the flat tree was accessed, I checked the DTLB and didn't find > any entry related to 0xc0be4300. After the exception, I found the > following DTLBs. > > 30 : 02 c0be4000 4KB ------ -> 00000000 > 31 : 00 fa000000 8MB VI-S-M -> fa000000 > > The DTLB#30 doesn't seem right. Why would it map to 0x0? I think this > should be something like 00be4000?
When the early_debug is enabled, the kernel can boot successfully. I checked the TLB settings and found the following. 28 : 00 c0000000 8MB V--S-M -> 00000000 29 : 00 fa000000 8MB VI-S-M -> fa000000 30 : 00 c0800000 8MB V--S-M -> 00800000 31 : 14 04919000 ?KB V---WM -> 00e45000 So the kernel can access the dtb at 0xbe4300 because of the pinned down DTLB#30. I think the cause is clear now. But how to fix it? Two questions: 1. Should this DTLB miss exception properly set a new TLB entry for the new dtb address 0xbe4300? 2. If the DTLB miss exception handler is not the right guy to load a proper TLB entry, how can I set one entry based on the link_address and the address of the flat dt blob? Thanks a lot, -Shawn. _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
