[U-Boot-Users] Field upgrade

[Thomas Lange <thomas@corelatus.com>]

Sure there is a sw solution! We have been using it for
2 years now. Check out board "gth".

We use a pre loader called miniboot, which boots the first
image with correct crc it finds in flash.

See http://www.opensource.se/

This allows us to upgrade u-boot in field. Even if we loose
power during upgrade, we will always have a valid u-boot
image to boot.

/Thomas

Wolfgang Denk wrote:
> In message <3FCCA417.9020500@2net.co.uk> you wrote:
> 
>>One of my requirements is that the firmware be field upgradeable. The 
>>problem at the moment is that if something goes wrong while erasing and 
>>programming a new u-boot there is no recovery without a jtag/bdm 
>>debugger. Does anyone have a solution, or is it not a problem in 
> 
> 
> There is no solution in software alone. If you have hardware  support
> which for example detects a failing boot (by waiting with timeout for
> a signal to be set by a successfully booting system) and then toggles
> for example boot devices you can do something like that.
> 
> But there is no simple way to do this in software alone.
> 
> 
>>practice? I was playing with the idea of having a backup u-boot and some 
>>method of falling back to it if the primary copy is corrupt.
> 
> 
> You can create a backup copy of U-Boot - but how will  you  boot  it?
> U-Boot  is  linked for a fix address so you cannot easily shift it in
> memory. And even if you could - your board will still  start  from  a
> fix reset vector - if it does not find valifd code there you may have
> a working image somewhere else but it will not help you.
> 
> Best regards,
> 
> Wolfgang Denk
>