[U-Boot-Users] Ensuring correctness of U-boot in the flash

[David Saada]

> I don't understand why this should be a problem. Reading the
> environment can be done by separate tools lile fw_printenv (see
> tools/env/).
Can I use it in non-GPL apps as well? Anyway as I mentioned before,
storing the CRC in the environment isn't suitable for us anyway.

> So  you  have  some  primary  bootstrap  loader  which  performs  the
> selection  and  switching? Well, sounds overly complicated to me, but
> it's your choice.
This is one option, but I don't like it because it's cumbersome indeed.
This is actually the implementation in our older (non U-boot) boards.
Another option we consider is to have two initially identical copies of
U-boot in the flash, say U-boot1 & U-boot2, where U-boot1 is considered
to be the non upgradeable boot, and U-boot2 is the upgradeable one. At
an early stage of U-boot1 (say board_init_f), it checks the CRC of
U-boot2, and if ok, it branches there (otherwise it continues as usual).
This way, in most of the cases U-boot2 is the "active" booter, and
U-boot1 is only used for failsafe purposes. It's just an idea at this
stage though.

> Why don't you enable the MD5 checksum feature then? It uses an
> embedded (in the image) MD5 checksum.
Sorry - searched throughout the code and documentation, and couldn't
find anything on MD5 checksum. Would appreciate more details.

Regards,
David.