Hi Tom,
On Sun, Aug 11, 2019 at 11:25:37PM +0200, Lukasz Majewski wrote:
Hi Peng,
Subject: [PATCH v2 07/11] imx: tpc70: dts: Add TPC70 board (imx6q based) device tree description
This commit defines the TPC70 imx6q board with device tree description.
Is the imx6q-kp.dtsi usable for this board from Linux kernel?
The imx6q-kp.dtsi is defined in the Linux kernel [1].
However, not all features - like backlight, CAN, etc. are needed in U-Boot. To reduce SPL footprint, as the TPC70 is the first board (from i.MX6Q family of SoCs) which uses only DM in SPL and U-Boot proper, only the necessary subset of [1] was added to U-Boot.
Note:
[1] - https://elixir.bootlin.com/linux/v5.2.8/source/arch/arm/boot/dts/imx6q-kp.dt...
Right, and that's what we have CONFIG_OF_SPL_REMOVE_PROPS for, yes?
Not quite. For example I need "clocks" property, which is defined for almost all nodes. This incurs some extra cost in terms of footprint.
To reduce the SPL size (to which dtb file size contributes), I had to not include full DTS from Linux in U-Boot.
I only used a subset of it (only _really_ necessary description to run U-Boot) to reduce size of SPL binary.
Best regards,
Lukasz Majewski
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