Re: [PATCH v10 2/2] arm64: dts: qcom: kodiak: Add EL2 overlay

[Sumit Garg]

Hey Folks,

On Mon, Jul 13, 2026 at 9:38 PM Mukesh Ojha
<mukesh.ojha@xxxxxxxxxxxxxxxx> wrote:
>
> All existing Kodiak board variants run the Gunyah hypervisor, which
> means Linux can only boot at EL1 on those devices. It is possible to
> boot Linux at EL2 on these devices [1].
>
> When running under Gunyah, remote processor firmware IOMMU streams are
> controlled by Gunyah. Without Gunyah, the IOMMU is managed by the
> Linux running at EL2. Describe the firmware streams for each
> remote processor in an EL2 overlay.
>
> Add an EL2-specific DT overlay and apply it to Kodiak IoT variant
> devices to produce a -el2.dtb alongside the standard dtb. Modem and
> media subsystems are not yet supported due to missing dependencies.
> The GPU zap shader is disabled. In EL2 mode the kernel owns the
> hardware watchdog, so it is enabled here. The wifi-firmware child
> node describes the IOMMU stream for the WCN6750 firmware; the &wifi
> node itself is left untouched so that platforms without WiFi are
> unaffected by the overlay.
>
> [1] https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
>
> Co-developed-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
> ---
>  arch/arm64/boot/dts/qcom/Makefile        | 12 ++++++++
>  arch/arm64/boot/dts/qcom/kodiak-el2.dtso | 39 ++++++++++++++++++++++++
>  2 files changed, 51 insertions(+)
>  create mode 100644 arch/arm64/boot/dts/qcom/kodiak-el2.dtso
>

Any updates on this patch if this can be picked up for the next merge window?

-Sumit

> diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
> index 1c857bd7991b..22076579a50f 100644
> --- a/arch/arm64/boot/dts/qcom/Makefile
> +++ b/arch/arm64/boot/dts/qcom/Makefile
> @@ -164,7 +164,11 @@ purwa-iot-evk-el2-dtbs     := purwa-iot-evk.dtb x1-el2.dtbo
>
>  dtb-$(CONFIG_ARCH_QCOM)        += purwa-iot-evk-el2.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcm6490-fairphone-fp5.dtb
> +
>  dtb-$(CONFIG_ARCH_QCOM)        += qcm6490-idp.dtb
> +qcm6490-idp-el2-dtbs := qcm6490-idp.dtb kodiak-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)        += qcm6490-idp-el2.dtb
> +
>  dtb-$(CONFIG_ARCH_QCOM)        += qcm6490-particle-tachyon.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcm6490-shift-otter.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs404-evb-1000.dtb
> @@ -176,12 +180,20 @@ qcs615-ride-el2-dtbs := qcs615-ride.dtb talos-el2.dtbo
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs615-ride-el2.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-radxa-dragon-q6a.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2.dtb
> +qcs6490-rb3gen2-el2-dtbs := qcs6490-rb3gen2.dtb kodiak-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2-el2.dtb
>
>  qcs6490-rb3gen2-vision-mezzanine-dtbs := qcs6490-rb3gen2.dtb qcs6490-rb3gen2-vision-mezzanine.dtbo
>  qcs6490-rb3gen2-industrial-mezzanine-dtbs := qcs6490-rb3gen2.dtb qcs6490-rb3gen2-industrial-mezzanine.dtbo
>
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2-industrial-mezzanine.dtb
> +qcs6490-rb3gen2-industrial-mezzanine-el2-dtbs := qcs6490-rb3gen2-industrial-mezzanine.dtb kodiak-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2-industrial-mezzanine-el2.dtb
> +
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2-vision-mezzanine.dtb
> +qcs6490-rb3gen2-vision-mezzanine-el2-dtbs := qcs6490-rb3gen2-vision-mezzanine.dtb kodiak-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-rb3gen2-vision-mezzanine-el2.dtb
> +
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-thundercomm-minipc-g1iot.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs6490-thundercomm-rubikpi3.dtb
>  dtb-$(CONFIG_ARCH_QCOM)        += qcs8300-ride.dtb
> diff --git a/arch/arm64/boot/dts/qcom/kodiak-el2.dtso b/arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> new file mode 100644
> index 000000000000..8daf7f02fd75
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> @@ -0,0 +1,39 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + *
> + * Kodiak specific modifications required to boot in EL2.
> + */
> +
> +/dts-v1/;
> +/plugin/;
> +
> +&gpu_zap_shader {
> +       status = "disabled";
> +};
> +
> +&remoteproc_adsp {
> +       iommus = <&apps_smmu 0x1800 0x0>;
> +};
> +
> +&remoteproc_cdsp {
> +       iommus = <&apps_smmu 0x11a0 0x0400>;
> +};
> +
> +&remoteproc_mpss {
> +       status = "disabled";
> +};
> +
> +&venus {
> +       status = "disabled";
> +};
> +
> +&watchdog {
> +       status = "okay";
> +};
> +
> +&wifi {
> +       wifi-firmware {
> +               iommus = <&apps_smmu 0x1c02 0x1>;
> +       };
> +};
> --
> 2.53.0
>