[U-Boot-Users] Need help booting linux on IBM 405EP eval board
Hi, guys.
I'm having a hard time getting U-Boot to boot Linux on an IBM 405EP evaluation board. Here's what I've tried:
First, I think my kernels are fine. I can compile 2.4.18 from an older version of the ELDK or I can compile 2.4.24 from the latest released ELDK. I'm using ELDK tools for all of my builds. Using the IBM bootloader that comes on the board and the "treeboot" image file format, I can get the IBM board to tftp my kernel over the lan and run it. So, I think the kernel is working fine.
I also don't have any problem running U-Boot. I compiled 1.0.2 and installed it on the board. U-Boot runs fine and I can make it tftp a file over the network as well. Using iminfo, I can see that it read what I expect. However, no matter what I try, I can't get the kernel to actually boot.
In the older kernel, I'm using a "make pImage" and in the newer kernel I do "make uImage". I've also tried running the mkimage tool manually with various options to see if I could get a kernel to boot. iminfo says the kernel is fine and I get to the "Uncompressing Linux Kernel ... OK" stage but it stops there.
I've noticed that the mkimage script is being called to set a start point and relocation point both of 0. Does that work on these boards? One person posted in the mailing list that you couldn't boot a kernel at 0. I've tried changing that to 400000 and it didn't help, though.
Another question I have is that I see 400000 embedded in at least one of the kernel build scripts. Is that a special number? Also, the kernel itself, by default, seems to build with a start point of 0xc0000000. On my system, that's not even RAM. But the kernels I built without changing that number boot fine with the IBM bootloader, so maybe it's not actually used in this environment.
I suspect I'm just running into some little interaction, like I need to change this number here or this number doesn't match that number. If anyone can give me some pointers, I'd appreciate it. We've used PPCBOOT in the past on other architectures without any problem, so I'm surprised that this is giving me fits.
Thanks Jeff
In message <1837411015.1080849758@[192.168.0.232]> you wrote:
I'm having a hard time getting U-Boot to boot Linux on an IBM 405EP evaluation board. Here's what I've tried:
Then this is a Linux question.
I also don't have any problem running U-Boot. I compiled 1.0.2 and
Then this is not an U-Boot question, i. e. it's off topic on this list.
various options to see if I could get a kernel to boot. iminfo says the kernel is fine and I get to the "Uncompressing Linux Kernel ... OK" stage but it stops there.
Did you read the FAQ?
I've noticed that the mkimage script is being called to set a start point and relocation point both of 0. Does that work on these boards? One person
Yes, this is correct for all PowerPC systems. As documented.
posted in the mailing list that you couldn't boot a kernel at 0. I've tried changing that to 400000 and it didn't help, though.
Please don't spread misinformation. At least quote the original posting - after checking that this was indeed for a PowerPC system, and checking if there were any follow-ups that corrected the false statement.
Another question I have is that I see 400000 embedded in at least one of the kernel build scripts. Is that a special number? Also, the kernel
No such number should be there if you really run "make uImage".
It is probably the link address for the Linux bootstrap loader code which is not necessary and will not be used when you use "make uImage".
itself, by default, seems to build with a start point of 0xc0000000. On my system, that's not even RAM. But the kernels I built without changing that
Correct. Welcome to the world of virtual addresses.
I suspect I'm just running into some little interaction, like I need to change this number here or this number doesn't match that number. If anyone
Don't change any of these. Not when you don't understand EXACTLY what you're doing.
Best regards,
Wolfgang Denk
participants (2)
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Jeff Tucker -
Wolfgang Denk