Quote:
Originally Posted by pazos
Hi Edu! I think the post is mine.
You can boot using a rootfs on a external sdcard but the kernel should be loaded at that point of time. That's it: we use a key combo to override the arguments passed to the kernel but we don't modify that kernel.
It should be possible to modify uboot to load a kernel stored on a ext2 partition (or in raw disk) but isn't recommended on your case, for the following reasons:
- uboot has a watchdog that resets the board each few seconds.
- uboot has the environment hardcoded and does a CRC32 check of that environment on boot.
- messing with uboot (or replacing the kernel) in a device with soldered EMMC is a bad idea because there's no way to recover that.
If you have other device with a user-replaceable sdcard then you can go straight and copy the kernel at the same offset. But, in your case, is too dangerous.
You can check if stock kernel has kexec support. In that case you can use the trick to boot from external sdcard and use kexec there to load your new kernel.
I hope the message is clear. Have fun with your lurking.  |
Hey thanks!, yes, quite clear. This kernel on the touch doesn't have kexec, but I've got another N437? It's a glo or hlo hd, which I remember having an internal sd card, so I could definitely use it.
I'll nonetheless, take the touch apart enough to be able to discern how many layers the board has, if it has the typical occluding embedded ground plane (If more than two layers), and whether I can access jtag, usart, or if these have already been brougth out on these seven pins the board has.
Thanks a lot!