u-boot on ARM PIC?

Hi,

I'll soon start an ARM based project (at91sam9g45), and am looking into booting options. I normally use PPC, so I'm not really familiar with the finer details of U-Boot on ARM. I would like to use a failsafe setup with 2x U-Boot images in NOR flash, and a mini bootloader (probably at91bootstrap based) to decide which to use. For that to work nicely, U-Boot would have to be PIC (pre-relocation).

I see there's CONFIG_SKIP_RELOCATE_UBOOT + CONFIG_LOWLEVEL_INIT. Can someone confirm that U-Boot is PIC on at91 if those two aren't defined, E.G. will it boot from any location in NOR?

Thanks.

Bye, Peter Korsgaard

Dear Peter Korsgaard,

Not really. Two different images linked for the respective addresses would do fine, too.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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Hi,

Wolfgang> Not really. Two different images linked for the respective Wolfgang> addresses would do fine, too.

Sure, but having a single image (certainly for a ping-pong system, E.G. where you keep the current and previous image) a single position independent image is nicer.

Does that work with u-boot on at91 given !SKIP_RELOCATE_UBOOT & !CONFIG_LOWLEVEL_INIT?

Bye, Peter Korsgaard

Take a look at board/netstar/crcek.S as exactly that is solved there (you may want to apply NetStar patches I sent to mailing list two weeks ago, which are being ignored as usual, so this is an usual rant). There are two images in NOR and only one can be written from Linux. This is done on update and then board is rebooted. 'Crcek' then verifies images and runs more recent version. It is up to u-boot to copy itself into lower location.

It boots from any NOR location on OMAP, so it should be the same for AT91.

Best regards,
ladis