Morning folks, As the title suggest im having issues geting my kernel started, and was hoping for some guidance.
In short i think my problems come from the MMU/Cache configuration being bad during the transfer from my boot loader to the kernel. Just as a quick aside i have confirmed my kernel boots using UBoot. but i wont be able to use uboot long term. My bootloader executes in RAM at 0x3e000000. It places the kernel at 0x2200000 and the device tree at 0x30000000 I have definitely heeded the warnings about debugging head.S and can verify this is not easy! I have added the following to head.S just before the decompression routines are called. debug_reloc_start debug_reloc_end During a bad bootup i get: 26B6CB50:00000000:00C5187D 00000000-268B463C>00000000 00000000 00000000: E59FF018 E59FF018 E59FF018 E59FF018 E59FF018 etc... on a good boot up i get obviously better values: 22247A60:00000000:00C5187D 00000000:2200019C>20008000 00000000 20008000: 473C5655 473C5655 473C5655 473C5655 473C5655 ... etc... There is a bit more kputc statements in head.S but they re before the pc is assigned to r0 and just after r4 gets its value. Can someone out there confirm that this looks like im not configuring (i.e. invalidating / emptying) the cache properly before jumping to Linux? Are there any other considerations that would cause this sort of behaviour on arm platforms ? Any or help or pointers very much appreciated. Many thanks. Dave Frost
