[Letux-kernel] [PATCH 00/20] A bunch of JZ4730 fixups for letux-kernel

[H. Nikolaus Schaller]

Hi Lubomir,

> Am 03.12.2020 um 10:34 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
> 
>> The newer U-Boot can also be
>> turned into an uImage and chain-booted from the factory loader, but I'd
>> have to dig out my notes.
> 
> Ok, that sounds a reasonable idea. Another approach would be to use a minimal
> uImage and use kexec to load the real thing. This is what the original system
> already does if I remember correctly with the initrd and minifs/recover concept [1].

After thinking about this, I guess it is easier to go the U-Boot way
since debugging the kernel until kexec works successfully is probably much
more complex and needs additional initrd setup.

And, it has to be done only once for newer kernel releases and changes.

Finally, there is a chance to make the second stage U-Boot load the device tree
so that we can get rid of the appended DTB which currently makes the L400 a quite
different setup than the CI20 (and potentially other devices).

So please let me know after you have dug out your notes.

In the meantime I have found:

http://bsdimp.blogspot.com/2016/09/chain-booting-u-boot-with-u-boot.html

which seems to indicate that we just have to compile the new U-Boot with
the Load and Execute address of Linux, pack and call it uImage. A minor
issue may be that the real Linux must be loaded somewhere else.
Or the load address of the second stage U-Boot could even differ from Linux
but should be inside RAM of course...

BR and thanks,
Nikolaus