[U-Boot-Users] Porting u-boot, using emulator, run from SDRAM

[Gerhard Butscher <gerhard.butscher@esk.fhg.de>]

Hello,

we try to get u-boot running on an Infineon Switch Evaluation Board
(MXU rev.B, MPC850). There is a VxWorks image in FLASH which is starting
and running correct.

We would like to stop the start of the VxWorks image with our Lauterbach
Emulator and then laod the u-boot bootloader into SDRAM and start
u-boot. This is already done (our script for Lauterbach works).

We started with the tqm850L configuration (u-boot 0.2.0), successively
changing/ commenting things. We already managed to modify the u-boot
code, so that we get to the u-boot command prompt, where we can enter
commands. Unfortunately we just hacked around and didn't really
understand well how the u-boot code could be adapted to our board.
Commenting out some RAM/FLASH size check routines and clock
discovery routines leads to not properly filled structures.

- Is there a simple #define switch to support u-boot running from SDRAM,
   loaded into RAM with an emulator? - I think this would be a nice
   feature in order to port the u-boot code to a new board.
- E.g. reading manufacturer ID of FLASH doesn't work at all. We also
   didn't manage to read this ID with issuing FLASH writes/reads from
   Emulator. But using the VxWorks boot prompt commands it works.

Maybe someone has some suggestions on how to go on.

Thanks,
Gerhard