thanks Scott 's following > I don't quite follow the above, but what I meant is that you need to > put a mapping in place that covers your LED I/O once you have the MMU on. > Any mappings that U-boot made will be gone at that point.
i am sorry for my poor expression. i think i have got your meaning about that. the suggestion from others that the situation that external access will be disabled at early booting time. i guess that means like yours, sometimes I/O disabled due to cache operating or something. certainly, if i have to turn LEDs at booting time, the way your said is the best. but i supposed i could operate LEDs after early booting time. >> i tried >> CONFIG_PPC_EARLY_DEBUG_CPM=y >> CONFIG_PPC_EARLY_DEBUG_CPM_ADDR=0xf00000008 >> how can i make sure CPM_ADDR, 0xf0000008 is default value > Look at the u-boot source, or dump the memory and see if it looks like a > ring buffer. sorry, i mean that CPM_ADDR is address of what? address of CPM registers or something? > This is a dts-v0 tree, which implies it's fairly old. dose later dts be used in corresponding kernel version ? i guess i must read "booting-without-of.txt". many of contents in dts i have no idea. in addition, there is one more question. my RAM size is 32MBytes, my "vmlinux" size is 30MBytes, "vmlinux.o" size is 58MBytes. so , will there be something wrong at uncompressing time ? Sauce -- View this message in context: http://www.nabble.com/issue-at-the-beginning-of-kernel-booting-tp22741532p22930588.html Sent from the linuxppc-dev mailing list archive at Nabble.com. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev