Hi Wolfgang,
thanks for your reply. That's the kind of thing I wanted to hear. Now I will start playing around ;-)
Matthias
On Tuesday 22 April 2008 22:49, Wolfgang Denk wrote:
In message 200804212302.30762.matthias.fuchs@esd-electronics.com you wrote:
Now I have to find a (simple) solution to solve my problem:
Typically the 405 board boots from onboard flash. Because of historic reason there is a kernel and a ramdisk image (not a multi image and nothing that is aware of any new image format). These images cannot be changed. When one of these images either one of them or both is corrupted, U-Boot should try to load both of them from a usb mass storage. So what's the best way to do so?
The key question here is your definition of "corrupted".
If reliability is an issue, you want to implement (1) support for a hardware watchdog combined with (2) support for a boot counter. Then you set "bootlimit" to a reasonable value and "altbootcmd" to the command required to load and boot from USB.
Such a setup will be very robust and handle even situations when the images look good (checksums are OK etc.) but fail to work (for example, because of buggy binaries or libraries were included, config files got corrupted, etc.).
- Make bootm fail when any image has a CRC error?
This is trivial to do. Remember that you can always use "imi" to check images; something like
=> imi $kernel_addr && imi $ramdisk_addr && bootm $kernel_addr $ramdisk_addr
would do what you want.
The new image format allows for even fancier methods.
Or implement a boot counter and let the board reset on corrupt images and then use "altbootcmd".
- Add a new command to check images and decide on the result
Not needed. "iminfo" already does that.
Any idea? I think the idea behind this is clear. When images A are not ok boot images B.
As mentioned above, the trick question is how you define when an image is OK.
Best regards,
Wolfgang Denk