[PATCH RFC 0/5] nvmem: Add a UEFI variable backed NVMEM provider

[Konrad Dybcio]

On 10/14/26 3:02 PM, Abel Vesa wrote:
> This is an RFC: I do not expect it to be merged as-is, it is sent to get
> feedback on the approach.
> 
> Some values a platform needs (for example the WLAN and Bluetooth MAC
> addresses on the Qualcomm laptops) are not always available to the kernel
> in a convenient form. They may live in firmware-owned SPI-NOR storage
> (e.g. a DPP partition) for which there is no straightforward, universally
> working way to read them from the non-secure world.
> 
> As an alternative, this series allows such values to be provisioned once
> into a UEFI variable and consumed in the kernel. It adds a generic NVMEM
> provider that exposes the contents of a UEFI variable as an NVMEM device,
> so the data can be consumed through the standard nvmem-cells bindings.
> MAC addresses are just the motivating use case; the provider itself is
> generic.
> 
> The first two patches are the actual proposal:
> 
>   - dt-bindings: nvmem: Add UEFI variable NVMEM provider
>   - nvmem: Add UEFI variable NVMEM provider
> 
> The remaining three patches are included only to illustrate how a
> consumer would use the provider; they are not meant for merging as part
> of this series:
> 
>   - Bluetooth: hci_qca: consume a "bd-address" nvmem cell
>   - wifi: ath12k: consume a "mac-address" cell
>   - arm64: dts: qcom: glymur-crd: wire both to a "MacAddresses" variable

I think we can take advantage of Loic's work here

https://lore.kernel.org/linux-arm-msm/20260507-block-as-nvmem-v2-0-bf17edd5134e@oss.qualcomm.com/

Konrad