Marco Antônio Possamai wrote:
Hello
I've been working on building a 2.6.26 linux kernel to the mpc5200Lite PowerPc board. However, I am unable to boot the system using the generated image.
I am using what seems to be the latest U-Boot for the job. Got it from www.denx.de/git/u-boot.git.
Good. :-)
I'm using the device tree compiler dtc-v1.2.0 to compile the device tree source into a device tree blob. Got it at: http://jdl.com/software/dtc-latest.tgz
Good, but *what* did you compile?
If this were /., I would insert an automobile analogy about you telling us all about the wrenches you used, how they were the best Binford-2000 lifetime guaranteed wrenches with more power, but never told us what part you were adjusting with the wrenches. http://en.wikipedia.org/wiki/Home_Improvement
For the device, my design procedure is the following:
- In the first step I generate the uImage file ('make ARCH=powerpc
zImage'), the corresponding lite5200b.dts and compile it to lite5200b.dtb. 2. Afterwards, I do the U-Boot configs. I define 0x00600000 as the device tree address and 0x00200000 as the uImage's. 3. Finally, I transfer them all (using tftp for each, of course) and try to boot: 'bootm 0x00200000 - 0x00600000'
The result is that the console hangs...
Is linux hung or is there no serial output? From the outside, the two symptoms are indistinguishable. If linux is actually running, it means your console/serial configuration in your dtb is not right. Use your debugger to halt the processor and see what/where it is executing. Dump the linux log buffer and see if there is anything interesting in there that wanted to go out the serial channel but couldn't.
Does anyone have any idea of why it happens? I checked a similar problem at the http://www.denx.de/wiki/view/DULG/LinuxHangsAfterUncompressingKernel, and I'm almost convinced that it is probably a bd_info problem, concerning the definitions of the kernel's IMAP_ADDR and the CFG_IMMR of U-Boot to be unmatching.
The flattened device tree replaces the bd_info structure as the way to communicate configuration info from u-boot to linux.
If that is the case, how/where can I correct it? Which files should I look for?
What are you using for your device tree source (.dts)? Odds are pretty good that is the problem. If that is OK, second best is if your console simply isn't configured properly. If neither of those are the case, you have some serious debugging ahead.
Thanks for the attention.
Marco Antônio Possamai
Universidade Federal de Santa Catarina
Good luck, gvb