[U-Boot] Dynamically define which Kernel image to boot during SPL execution

[bin4ry <0xbin4ry@gmail.com>]

Am 06.10.2013 21:31, schrieb Wolfgang Denk:
> Dear 0xbin4ry,
>
> don't you have a real name?
Yes indeed, Peter.
> What would "u-boot.img" be here - the full U-Boot image loaded by the
> SPL?  If you load and start that, then this would be the place where
> you determine which kernel image to load and start.
The only code I found in the SPL regarding the call of u-boot.img were
the following functions:

mmc_load_image_fat() -> file_fat_read() -> do_fat_read() [here, the
u-boot.img file is copied to DDR memory] -> jump_to_image_no_args()
[here, we excute the u-boot.img code].

However, I could not find any signs of any boot parameters (except for
CONFIG_EXTRA_ENV_SETTINGS in omap4_common.) but I could not figure how
to dynamically alter these parameters.
>   However, if
> you're uysing Falcon mode, then you would not load any u-boot.img at
> all, and the SPL would include the code to determine which kernel
> image to load and start.
I guess I have to read about falcon mode. Did not know about this before.

Basically, I want to determine which Android kernel to boot based upon a
calculation executed by the SPL. Maybe you know if more elegant ways
then the ones I am thinking of.

A little bit off-topic, however it could help my in this scenario
anyways: Is it possible to show a splash screen in the SPL or the loaded
u-boot.img on an OMAP4460? I browsed the web and found several
statements that this is not supported. However, these statements seemed
to be rather vague..

Best regards,
Peter