Re: [PATCH v2 2/2] ARM: dts: Add nvmem node for BCM2711 bootloader public key

From: Stefan Wahren
Date: Thu Apr 13 2023 - 14:46:00 EST


Hi Ivan,

Am 13.04.23 um 20:18 schrieb Ivan T. Ivanov:
On 04-13 18:15, Stefan Wahren wrote:

Hi Ivan,

Am 13.04.23 um 10:52 schrieb Ivan T. Ivanov:
From: Tim Gover <tim.gover@xxxxxxxxxxxxxxx>

Make a copy of the bootloader secure-boot public key available to the OS
via an nvmem node. The placement information is populated by the
Raspberry Pi firmware if a public key is present in the BCM2711
bootloader EEPROM.

It would be nice to have a helpful link like:
https://www.raspberrypi.com/documentation/computers/configuration.html#nvmem-nodes

Yep, make sense.

+
+ /*
+ * RPi4 will copy the binary public key blob (if present) from the bootloader
+ * into memory for use by the OS.
+ */
+ blpubkey: nvram@1 {
+ compatible = "raspberrypi,bootloader-public-key", "nvmem-rmem";

Yes this looks better, but this introduce a new dtbs_check issue. The new

Oops, yes, I forgot to make this check.

compatible must be documented in
Documentation/devicetree/bindings/nvmem/rmem.yaml in a separate patch and
reviewed by the DT guys.

Or I can drop the new compatible string altogether? It looks like
only alias is strictly required?! Tim Gover is this correct?

i cannot speak for the firmware side, but i think we should try to keep it compatible with the vendor DTB here.


Regards,
Ivan