Re: [PATCH RFC u-boot-mvebu 00/59] arm: mvebu: Various fixes

Pali Rohár
2023-02-26T08:14:24Z

On Sunday 26 February 2023 01:56:23 Martin Rowe wrote:
> On Sat, 25 Feb 2023 at 21:16, Pali Rohár <pali@kernel.org> wrote:
> > I think that the remaining part is to patch linux DTB file at runtime
> > for emmc support. So if u-boot mmc device is of eMMC type then fixup
> > linux dtb file and others do nothing.
>
> One question I didn't think of when suggesting this: does runtime
> patching the kernel's dtb break signed/verified booting

I do not think so. Signature verification should be done before
patching.

> The reason I
> ask is because we now only need to patch the kernel dtb, not the
> u-boot one. If we needed to do both, then it would make sense to
> handle them in the same way through u-boot. The barrier to creating a
> patched kernel dtb file on its own is very low, so I'm not sure adding
> some "magic" to u-boot to make it work is the best solution,
> especially if it might break verified boot.