Failsafe bootloader

Wolfgang Denk wd at
Thu Jun 5 00:13:47 EST 2003

In message <3EE8E5EA at> you wrote:
> We use small part of our flash to hold config data (last sector of the flash)
> and which image must be started. PPCBoot read this and start the right image.
> when upgrading , we change the kernel option to the failsafe kernel, do the
> update of the second kernel (the working one) and after that we change the
> kernel option again and we try to start the new one. We use also a kind of
> watchdog feature in case of system lockout.

It may be worth to point out that  U-Boot  supports  redundand  flash
sectors  for exactly such purposes, so you will always have a working
backup copy in case the update  of  your  config  data  (=environment
variables) sector fails because of powerdown etc.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at
God made the integers; all else is the work of Man.       - Kronecker

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