Dear Grant,
in message 528646bc050212001475fc6c92@mail.gmail.com you wrote:
Wolfgang, regardless of the fact that the FAQ says that u-boot must run out of FLASH, in this scenario it will be running out of SDRAM.
This is not quite correct. The FAQ says that it *is* possible, but you'd better understand what you are doing. There are situations (like flash- and ROM-less systems) where this is perfectly legal - or even the only way to run any software at all. For example, consider a PCI card where U-Boot gets loaded into pre-initialized RAM by software running on the host computer.
The FAQ entry is intended to stop people with standard systems (i. e. such booting from on-board flash) to use such an approach thinking it would save them time or effort.
Now, from what I know, I cannot see this being a problem because with the VIIPro+SystemACE there is no SDRAM initialization that the bootloader is responsible for. Plus there is absolutely no FLASH device available anyway. Do you see this as a problem? If so, what are the likely issues that Roger may see?
I don't see any inherent problems.
Note; BRAM may be expensive so it is desirable to keep it as small as possible; especially considering that the SystemACE loads the VIIPro via JTAG. Big Image=Slow Boot. I would make the first stage loader as dumb as possible.
Especially in such a situation it might make sense to include zlib functionality into the first stage loader - a compressed U-Boot image will load faster (assuming your processor is fast enough).
Best regards,
Wolfgang Denk