Re: [PATCH RFC 0/3] mmc: sdhci-brcmstb: Add rpmb sharing support
From: Florian Fainelli
Date: Tue Feb 11 2025 - 12:02:03 EST
On 2/11/25 00:13, Avri Altman wrote:
This patch set adds support for Broadcom TZOS to read and write to
RPMB partition using synchronized access to the controller hardware.
Practically it establishes a communication channel between the trust zone and the host controller regardless of the rpmb protocol.
Or did I get it wrong?
Rather than communication channel, I would describe it as an arbitration
scheme between N participants, with guaranteed forward progress and
fairness between all participants.
The interest here is for one of those participants to own the eMMC
controller for a certain amount of time and indicate when it is done
with it. This is not specific to eMMC as this could scale to virtually
any piece of HW that is driven by transactions from a CPU, but the main
application is for allowing the Trusted OS to own the eMMC controller
for a short period of time in order to do its RPMB access, and then give
it back in the same state it found it to the next participant.
--
Florian