Hi,
Now I am trying to embed linux onto our MPC860-based board. I have
some questions which may be solved by you embed-linux gurus....
What I want to do is the following:
1 Initialize the MPC860 CPU , memory, serial port, enet port .
2 Download the linux powerpc kernel (which I have cross-compiled
on my X86 box)
from the TFTP server to RAM on board.
3 run the kernel.
Now the 1 and 2 step work well, but when I download the kernel to RAM on
board, It just cannot run.Do you know why? How can I programme to make
it run? Since the kernel is a compressed image (zvmlinux), need I make
some codes to decompress it and then run it? if so, how to do it?
Thank you very much :-))
Merry christmas & happy year.
dony
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
dony wrote:
Hi,
Now I am trying to embed linux onto our MPC860-based board. I have
some questions which may be solved by you embed-linux gurus....
What I want to do is the following:
1 Initialize the MPC860 CPU , memory, serial port, enet port .
2 Download the linux powerpc kernel (which I have cross-compiled
on my X86 box)
from the TFTP server to RAM on board.
3 run the kernel.
Now the 1 and 2 step work well, but when I download the kernel to RAM on
board, It just cannot run.Do you know why? How can I programme to make
it run? Since the kernel is a compressed image (zvmlinux), need I make
some codes to decompress it and then run it? if so, how to do it?
So I take it that you have written your own boot loader that is in
ROM/Flash which fetches the kerenl from a TFTP server and places it in RAM
somewhere. Good. How does your bootloader know where to put the code ?
Does it look at the internals of the elf image or is it an s-record file
you are downloading ? The image must be placed at or above 2MB. You will
have problems if it is below 2MB. I have my kernel in Flash at FFE00000 or
FF800000. Once the kernel is loaded, you have to jump to the start
address.
I assume you are using the mbxboot code for the kernel. Are you ? What
board are you using ?
The mbxboot code will copy the iteself to location 0x100000 (1MB) and jump
to that address so it is running from RAM. It then decompress the kernel
image to location 0 and jumps to the start of the kernel.
Can you send the output of "objcopy --headers zImage" to the list. Also
send the output of the mbxboot loader messages with the loaded and
relocated addresses (if the code is getting that far).
Brendan Simon.
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/