From: Aurelien Jarno <aurelien@xxxxxxxxxxx> Add the '-@' DTC option for the Raspberry Pi devices. This option populates the '__symbols__' node that contains all the necessary symbols for supporting device-tree overlays (for instance from the firmware or the bootloader) on these devices. The Rasbperry Pi devices are well known for their GPIO header, that allow various "HATs" or other modules do be connected and this enables users to create out-of-tree device-tree overlays for these modules. Please note that this change does increase the size of the resulting DTB by ~40%. For example, with v6.4-rc1 increase in size is as follows: bcm2711-rpi-400.dtb 27556 -> 38141 bytes bcm2711-rpi-4-b.dtb 27484 -> 38069 bytes bcm2711-rpi-cm4-io.dtb 27373 -> 38076 bytes bcm2837-rpi-3-a-plus.dtb 14930 -> 20713 bytes bcm2837-rpi-3-b.dtb 15107 -> 20979 bytes bcm2837-rpi-3-b-plus.dtb 15463 -> 21443 bytes bcm2837-rpi-cm3-io3.dtb 14429 -> 20098 bytes bcm2837-rpi-zero-2-w.dtb 14781 -> 20524 bytes Signed-off-by: Aurelien Jarno <aurelien@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220410225940.135744-2-aurelien@xxxxxxxxxxx [ukleinek: rebased to v6.4, replaced by a single assignment to DTC_FLAGS] Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> --- arch/arm64/boot/dts/broadcom/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile index 05d8c5ecf3b0..8b4591ddd27c 100644 --- a/arch/arm64/boot/dts/broadcom/Makefile +++ b/arch/arm64/boot/dts/broadcom/Makefile @@ -1,4 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 + +# Enables support for device-tree overlays +DTC_FLAGS := -@ + dtb-$(CONFIG_ARCH_BCM2835) += bcm2711-rpi-400.dtb \ bcm2711-rpi-4-b.dtb \ bcm2711-rpi-cm4-io.dtb \ -- 2.39.2
