Re: [U-Boot] [RFC] Kbuild support for ARM FIT images

Peter Korsgaard
2013-02-21T20:56:11Z

>>>>> "Jason" == Jason Gunthorpe <jgunthorpe@obsidianresearch.com> writes:

Hi,

Jason> We've been using DT on production embedded stuff sice about 2.6.20ish
Jason> on PPC and now ARM. We treat the dtb as a kernel version specific
Jason> file, much like an initrd and ensure that the kernel only ever boots
Jason> with its proper dtb. This is based on experience that the dtbs change
Jason> depending on the state of the drivers in the kernel, what gets
Jason> mainlined and when, etc.

Jason> Embedding this stuff into the bootloader is *not* desirable for my
Jason> embedded scenarios. We don't use FIT (or uboot) but we do the same
Jason> thing: a single image is constructed with the proper dtb, kernel and
Jason> initrd, and that is what the bootloader boots.

Jason> Why? This is an embedded appliance product. We need to be able to
Jason> deliver firmware upgrades that *work*. We can't brick the board
Jason> because the bootloader and kernel get out of sync. The boot loader has
Jason> to be *simple*, it has to boot every past, present and future kernel
Jason> or we start taking risks that a firmware flash will end up bricking
Jason> it.

I'm having the exact same experience (and handle it in the same way).

I know this was not the intention of DT, but unfortunately this is how
things have turned out so far.

--
Bye, Peter Korsgaard