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Topic: Chumby Classic stuck at "Jumping to kernel" (bricked)

Hi there.

I made a custom psp.bin partition, and flashed it with the alternate boot. It hanged at "writing psp image", so after a while I took off the power and rebooted. Now it stop at "jumping to kernel".

I have access to the serial port, and the bootloader is fine. Is there a way to flash back the original kernels, root file systems and psp partitions?

Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

Can you get it to boot into safe mode?

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Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

What do you mean by safe mode? If is the alternate boot, the one that start if you press the touchscreen, than no. It hangs with the same massage "jumping to kernel". I think that during the psp writing procedure it didn't stop at the partition boundaries and run to the end of the flash memory, wipeing out all the system. This was possibly caused by an incorrect psp.bin image file (too small and without the necessary padding)

Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

If that's the case, then it's very likely bricked. Unfortunately, we don't have the equipment to unbrick it.

You have to be super careful when messing with Classic like this.  It's one reason we switched to SD cards for C1 - it's "unbrickable" since you can simply replace the card.

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Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

Is it possible to write to the flash chip via jtag or something similar? Probably I have the necessary equipment. Also, could you give me the right instructions to make a valid psp.bin image? I've read other posts on the forum but if you can give me the instructions that you use to build the psp.bin.zip file, that would be very helpfull.

Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

I don't think you can write to the NAND through JTAG, but I might be wrong there.  The code to write to NAND is much more complicated than reading due to bad block management, so it's not something that this interface would likely support.

If you can find a way, we can provide a dump of the ROM.  The device schematics for Classic should still be available here.

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Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

Ok. And what about this post http://forum.chumby.com/viewtopic.php?id=1145 ? is it a viable option? Can I have access to this tools? We have like 120~130 chumby classic and it's probably a good idea to have a recovery plan ready.

Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

Yeah, that might work - basically, the goal is to boot just enough of a Linux running in RAM, then using that to rewrite the partitions on NAND using the Linux driver.  It's been a very long time since anyone attempted this.

All of the links on that post that point to our site should be still available.  If not, chances are we don't have it anymore.

You can also try to reach bunnie at his bunniestudios email address.

Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

I just read through the iMX21 reference manual, and indeed there is a way to load software into through the serial post and boot it.  The post you linked about is pretty much correct about how this works.  You have to pull down some pins on the board to get the device into this mode (which is tough to do on an intact Classic).

If you have access to this manual, it's chapter 10.

Re: Chumby Classic stuck at "Jumping to kernel" (bricked)

ilario wrote:

We have like 120~130 chumby classic

Wow.

Linux Guy - Occasional Chumby Hacker