On Tue, Apr 7, 2020 at 10:35 AM Atish Patra atishp@atishpatra.org wrote:
On Mon, Apr 6, 2020 at 11:51 PM Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
On Tue, 7 Apr 2020 at 08:46, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 4/6/20 11:01 PM, Ard Biesheuvel wrote:
On Mon, 6 Apr 2020 at 22:45, Atish Patra atish.patra@wdc.com wrote:
This series adds few DT related fixes required for Linux EFI stub to work on RISC-V.
I'm not sure how this is supposed to work, since DT reserved memory regions are not used by EFI. If you want to reserve memory on a UEFI system, you have to reserve it in the UEFI memory map from firmware. The DT reserved-memory node is taken into account too late, the /memreserve/ entries are ignored entirely.
Hello Ard,
thanks for reviewing.
What do you mean by "The DT reserved-memory node is taken into account too late"?
Cf. commit 7be64b885a36 ("cmd: bootefi: Parse reserved-memory node from DT")
What I mean is that the EFI stub in Linux uses memory allocation functions, expecting the firmware to ensure that those allocations do not conflict with memory descriptions and reservations in DT. So if the firmware wants to express this redundantly, by passing reservations in both reserved-memory and in the EFI memory map, that is probably fine.
Also, I must sheepishly admit that I only realize now that this patch set is against u-boot not Linux :-)
:)
So if fixed reserved-memory regions are only being used to seed the reserved regions in the EFI memory map, you can safely ignore me.
Yeah. That's the purpose. Having reserved memory nodes in the final DT used by linux also ensures that proper Linux adds a reserved memory block or removes it from memblock entries depending on "no-map" property.
Apologies for the noise.
-- Regards, Atish
Any other comments on the series ? It would be great if this series could be merged before v2020.07 release.