Re: [PATCH v3 0/5] Add pmem node for preserving distro ISO's

[Tobias Waldekranz <tobias@waldekranz.com>]

On fre, jan 24, 2025 at 13:39, Ilias Apalodimas <ilias.apalodimas@linaro.org> wrote:
> Heinrich, Tobias
>
> There's a slight problem that I forgot when commenting v2.
>
> Heinrich's idea of plugging this into blkmap is eventually the right
> thing to do.
>
> However, when I started coding this I only added the pmem memory as
> 'reserved' in the DT hoping that would work.
> Unfortunately, this depends on a kernel config option. I've managed to
> track down the problem here[0], but I haven't found time to test it
> properly and send it upstream.
> So for this feature to work reliably we *need* to remove the memory
> map we hand over to the OS.
>
> Since using EFI memmap function into the blkmap code makes no sense,
> can we perhaps merge v2 (or a variant of it), which only targets EFI,
> with an explanation of *why* while I try to sort out the kernel issue?

I was not a part of the first two iterations of this series, but my view
is basically this:

Adding some flag to memory backed slices of block maps, that the
fdt-fixup code can use to know whether a pmem node should be injected or
not, is completely fine by me.

What I am opposed to is adding restrictions on how block maps can be
composed, i.e., limiting a block map to only contain either linear or
memory mappings.