Hello Wolfgang,
On Thu, May 29, 2008 at 12:41 AM, Wolfgang Denk wd@denx.de wrote:
in message c384c5ea0805281514r1740072fw7c49101a4535f818@mail.gmail.com you wrote:
For how long can I expect current u-boot (say 1.3.4) to be forward compatible with newer Linux kernels?
I think chances are pretty good. Please keep in mind that we're right
But even today you can build a current Linux kernel using the cuImage wrapper and boot it on an old (say, version 1.2.0) U-Boot.
Thanks for your clear answer, takes away my cloud of doubt.
Also, is there any plan to add fail-safe features to u-boot?
What are you thinking of?
My main requirement is to have the bootloader make a decision to boot a fall back image in case the normal image does not boot (for whatever reason). The fall back image is a user friendly way to unbrick the device. It itself is never overwritten. (In my case a web server with firmware upgrade Java applet, for example).
Currently, my flow is as follows (with implementation in redboot)
boot loader: enable hardware watchdog if flag A is set clear flag A load normal image, boot else if the normal image was not loaded, boot fallback. else boot fallback
the normal image sets flag A when it wants to reboot, then stops servicing the watchdog and resets
if normal image either did not set flag A (it crashes) or it did not service the watchdog, the watchdog will reset the board.
I wonder if this is a common use and if it makes sense to implement this for mainstream u-boot, or is this very specific?
Regards,