[Qemu-devel] Flash emulation questions

[Qemu-devel] Flash emulation questions

[Alex Bennée]

Hi Phillipe,

There has been some interest expressed in adding support for RPMB flash
partitions for the benefit of secure firmwares like OPTEE. I'm just
trying to scope out what sort of work would need to be done for it.

RPMB (Replay Protect Memory Block) is a special eMMC partition which
requires a key and write counter to unlock and write sectors to it. It's
not clear if the partition itself is only accessible to the secure world
or if that's just the only part of the world that has a copy of the key
to do the unlock sequence.

So a few quick questions:

Do we have a common emmc emulation in QEMU?

It seems there are numerous hw specific bits (omap_mmc, pxa2xx_mmci) and
what looks like a common sd.c. Would this be the place to support RPMB?

I assume the easiest way would be to add some qdev properties that can
enable RPMB behaviour for segments of the flash which can be set when
the machine initializes.

Where do the pflash device types sit in this scheme?

They are the default goto device for bios flash devices on a range of
machines but AIUI they follow a different flash programming spec (Intel
or AMD). Would we want to be able to instantiate a "virt" machine with a
sdhci backed flash instead of the default pflash? Should we have a new
machine type that defaults to secure components?


--
Alex Bennée