Changes in the Qualcomm Linux kernel - Qualcomm Dragonwing Documentation

Qualcomm Linux 2.0 uses a restructured kernel configuration. Consider the following key updates and improvements to migrate kernel configurations and device trees from Qualcomm Linux 1.0 to Qualcomm Linux 2.0. To build the kernel, the Qualcomm Linux kernel BSP uses one of the kernel configuration fragments listed in the following table: Table: Kernel configuration fragments

Kernel configuration fragments	Description
`<kernel_src>/arch/arm64/configs/defconfig`	Upstream Arm64 defconfig used as the base configuration.
`<kernel_src>/arch/arm64/configs/prune.config`	Prunes unwanted configurations from the upstream defconfig to optimize build time.
`<kernel_src>/arch/arm64/configs/qcom.config`	Enables Qualcomm configuration that isn’t part of the upstream defconfig.
`<kernel_src>/kernel/configs/debug.config`	Enables standard kernel debug configuration.
`<kernel_src>/kernel/configs/hardening.config`	Enables security configurations to harden the production kernel.
`<kernel_src>/arch/arm64/configs/rt.config`	Enables `PREEMPT_RT configurations` for real-time kernel support.

Migrate the device tree from Qualcomm Linux 1.0 to Qualcomm Linux 2.0

The Qualcomm device tree source include (DTSI) and device tree source (DTS) files for supported Qualcomm kits are located in the kernel source in the arch/arm64/boot/dts/qcom/ directory. Qualcomm Linux 2.0 aligns all device trees to upstream, adhering to standard device tree bindings. Hence, there are no addons device tree fragments that carry downstream additions. The following table compares the device tree layout between Qualcomm Linux 1.0 and Qualcomm Linux 2.0:

QCS6490
IQ-9075
IQ-8275
IQ-615

The following table lists the Qualcomm device tree files for the Qualcomm Dragonwing™ RB3 Gen 2 Development Kit:

		Table: Qualcomm device tree source
Qualcomm Linux 1.0	Qualcomm Linux 2.0	Details
arch/arm64/boot/dts/qcom/sc7280.dtsi	arch/arm64/boot/dts/qcom/kodiak.dtsi	The QCS6490 SoC DTSI has been renamed.
arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts arch/arm64/boot/dts/qcom/qcs6490-addons-rb3gen2.dts	arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts	Device tree source for the QCS6490 Qualcomm Dragonwing™ RB3 Gen 2 Development Kit; no addons.
arch/arm64/boot/dts/qcom/qcs6490-addons-rb3gen2-vision-mezz.dts	arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-vision-mezzanine.dts	QCS6490 Qualcomm Dragonwing™ RB3 Gen 2 Vision Mezzanine Development Kit.
arch/arm64/boot/dts/qcom/qcs6490-addons-rb3gen2-ia-mezz.dts	arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dts	QCS6490 Qualcomm Dragonwing™ RB3 Gen 2 Industrial Mezzanine Development Kit.

The following table lists the Qualcomm device tree files for the Qualcomm Dragonwing™ IQ-9075 EVK:

		Table: Qualcomm device tree source
Qualcomm Linux 1.0	Qualcomm Linux 2.0	Details
arch/arm64/boot/dts/qcom/sa8775p.dtsi	arch/arm64/boot/dts/qcom/lemans.dtsi	The DragonwingTM IQ-9100 SoC is derived from IQ-9075 and renamed accordingly.
arch/arm64/boot/dts/qcom/qcs9100-ride.dts arch/arm64/boot/dts/qcom/qcs9100-ride-r3.dts arch/arm64/boot/dts/qcom/qcs9100-addons-ride.dts arch/arm64/boot/dts/qcom/qcs9100-addons-ride-r3.dts	arch/arm64/boot/dts/qcom/qcs9100-ride.dts arch/arm64/boot/dts/qcom/qcs9100-ride-r3.dts	Qualcomm Linux evaluation kit for DragonwingTM IQ-9075 Ride.
arch/arm64/boot/dts/qcom/qcs9075-iq-9075-evk.dts arch/arm64/boot/dts/qcom/qcs9075-addons-iq-9075-evk.dts	arch/arm64/boot/dts/qcom/lemans-evk.dts	Qualcomm Linux development kit for the Qualcomm DragonwingTM IQ-9075 Evaluation Kit (EVK).

Table: Qualcomm device tree source
Qualcomm Linux 1.0	Qualcomm Linux 2.0	Details
arch/arm64/boot/dts/qcom/qcs8300.dtsi	arch/arm64/boot/dts/qcom/monaco.dtsi	The Dragonwing IQ-8275 SoC is derived from QCS8300.
arch/arm64/boot/dts/qcom/qcs8300-ride.dts arch/arm64/boot/dts/qcom/qcs8300-addons-ride.dts	arch/arm64/boot/dts/qcom/qcs8300-ride.dts	Qualcomm Linux development kit for Dragonwing IQ-8300 Ride.
arch/arm64/boot/dts/qcom/qcs8275-iq-8275-evk.dts arch/arm64/boot/dts/qcom/qcs8275-addons-iq-8275-evk.dtso	arch/arm64/boot/dts/qcom/monaco-evk.dts	Qualcomm Linux development kit for the DragonwingTM IQ-8275 EVK.

The following table lists the Qualcomm device tree files for the Qualcomm DragonwingTM IQ-615 Development Kit: By default, the addons DTB is used.

Table: Qualcomm device tree source
Qualcomm Linux 1.0	Qualcomm Linux 2.0	Details
arch/arm64/boot/dts/qcom/qcs615.dtsi	arch/arm64/boot/dts/qcom/talos.dtsi	The base configuration file for the Dragonwing IQ-615 SoC.
arch/arm64/boot/dts/qcom/qcs615-ride.dts arch/arm64/boot/dts/qcom/qcs615-addons-ride.dts	arch/arm64/boot/dts/qcom/qcs615-ride.dts	The base configuration file for Dragonwing IQ-615 ride.

Note The device tree files marked with el2 are intended for Linux configurations running at Exception Level 2 (EL2), such as kernel-based virtual machine (KVM). The el2 overlays are applied on the platform DTB to generate the corresponding EL2 DTB variants. Use these EL2-specific DTBs only when Linux is required to operate as a KVM hypervisor. For example, arch/arm64/boot/dts/qcom/lemans-el2.dtso.

​Migrate the device tree from Qualcomm Linux 1.0 to Qualcomm Linux 2.0

Migrate the device tree from Qualcomm Linux 1.0 to Qualcomm Linux 2.0