[U-Boot] How to test new bootloaders on Jetson TX1?

[Mikko Perttunen]

On 15.02.2018 15:25, Andreas Färber wrote:
> Hi Mikko,
>
> Am 15.02.2018 um 08:56 schrieb Mikko Perttunen:
>> In the cboot + U-Boot combination, cboot loads U-Boot from the usual
>> kernel partition (LNX or kernel depending on system), so flashing U-Boot
>> there should do the trick. I believe this did indeed change in some L4T
>> version, so the wiki page needs to be updated. Tom should know more
>> about this.
>
> Thanks for explaining.
>
> The LNX partition is getting a boot.img - what is the relation to the
> four U-Boot files? flash.sh source is not really helping here.

cboot is only capable of booting Android .img's so the U-Boot binary 
(u-boot-dtb.bin according ton Jon) is packaged as one using mkbootimg or 
similar - I expect flash.sh to do this automatically.

>
> Might any changes to RP1 and/or DTB partitions be necessary to match my
> newer U-Boot, or does U-Boot use an internal .dtb these days?

My understanding is that it uses an internal .dtb.

>
> Is there any more efficient way to flash just U-Boot? -k LNX possibly?

That might work. Jon should know the details.

>
> I had played with the -L option before (which mentions u-boot-dtb.bin),
> but recall it ran into some form of checksum error on boot when passing
> it my file...
>
>> I expect Varun to know the details about ATF, but I'll check if I can
>> find some answer myself.
>
> Thanks again for your efforts.

I found out that ATF and optionally a secure OS (Trusty usually) are 
contained in the file tos.img. The image contains a padded header, 
followed by bl31.bin and the secure OS binary concatenated.

The header format should be pretty straightforward to reverse-engineer 
(need to change some fields specifying lengths), but I'll ask around if 
we can get a script to generate it released.

Cheers,
Mikko

>
> Regards,
> Andreas
>