[U-Boot] [linux-sunxi] Re: Proposal to add NAND-boot support for Sunxi SPL

[Henrik Nordström]

fre 2015-05-22 klockan 15:51 +0200 skrev Hans de Goede:

> What info do we need when we're only reading ? If the BROM can get away with a fixed
> way of reading the nand for booting, we should be able to make the SPL get
> away with it too ...

BROM tries at least 4 different strategies in reading the NAND boot
blocks. Two different NAND protocol strategies and two different format
strategies have been observed (4 different access patterns). And ontop
of this it tries both randomizer scrambled and plain access.

> Distros already need to build and distribute a u-boot-with-spl.bin per supported
> board. This doubles the number of builds they have to do and the number of
> files they need to distribute. If at all possible I would really like
> to have a unified SPL binary.

The SPL shrinks considerably in size if built in thumbs mode.

What I envisioned for sunix u-boot SPL was board-agnostic SPL binaries
with a little configuration header. This way you only need two (or three
is SPI is added) binaries, a list of board configurations and tool for
applying the config and write the resulting binary to the boot device
(NAND/MMC/SPI)

There isn't really that many board specific parameters.

Regards
Henrik