Message ID | 20220410225940.135744-2-aurelien@aurel32.net (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | arm/arm64: dts: Enable device-tree overlay support for RPi devices | expand |
Hello, [expanded Cc: to include William Zhang and Florian Fainelli] On Mon, Apr 11, 2022 at 12:59:39AM +0200, Aurelien Jarno wrote: > 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 v5.17 increase in size is as follows: > > bcm2711-rpi-400.dtb 26481 -> 36830 bytes > bcm2711-rpi-4-b.dtb 26537 -> 36886 bytes > bcm2711-rpi-cm4-io.dtb 26426 -> 36945 bytes > bcm2837-rpi-3-a-plus.dtb 14133 -> 19740 bytes > bcm2837-rpi-3-b.dtb 14310 -> 20006 bytes > bcm2837-rpi-3-b-plus.dtb 14670 -> 20474 bytes > bcm2837-rpi-cm3-io3.dtb 13680 -> 19266 bytes > > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> > --- > arch/arm64/boot/dts/broadcom/Makefile | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile > index 5082fcd1fea5..0aa8ee2afdd5 100644 > --- a/arch/arm64/boot/dts/broadcom/Makefile > +++ b/arch/arm64/boot/dts/broadcom/Makefile > @@ -1,4 +1,15 @@ > # SPDX-License-Identifier: GPL-2.0 > + > +# Enables support for device-tree overlays > +DTC_FLAGS_bcm2711-rpi-400 := -@ > +DTC_FLAGS_bcm2711-rpi-4-b := -@ > +DTC_FLAGS_bcm2711-rpi-cm4-io := -@ > +DTC_FLAGS_bcm2837-rpi-3-a-plus := -@ > +DTC_FLAGS_bcm2837-rpi-3-b := -@ > +DTC_FLAGS_bcm2837-rpi-3-b-plus := -@ > +DTC_FLAGS_bcm2837-rpi-cm3-io3 := -@ > +DTC_FLAGS_bcm2837-rpi-zero-2-w := -@ Instead of setting these all explicitly a single DTC_FLAGS := -@ would work, too, without changing how the dts in subdirs are compiled. IMHO this would be suiteable for arch/arm64/boot/dts/broadcom. Best regards Uwe
diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile index 5082fcd1fea5..0aa8ee2afdd5 100644 --- a/arch/arm64/boot/dts/broadcom/Makefile +++ b/arch/arm64/boot/dts/broadcom/Makefile @@ -1,4 +1,15 @@ # SPDX-License-Identifier: GPL-2.0 + +# Enables support for device-tree overlays +DTC_FLAGS_bcm2711-rpi-400 := -@ +DTC_FLAGS_bcm2711-rpi-4-b := -@ +DTC_FLAGS_bcm2711-rpi-cm4-io := -@ +DTC_FLAGS_bcm2837-rpi-3-a-plus := -@ +DTC_FLAGS_bcm2837-rpi-3-b := -@ +DTC_FLAGS_bcm2837-rpi-3-b-plus := -@ +DTC_FLAGS_bcm2837-rpi-cm3-io3 := -@ +DTC_FLAGS_bcm2837-rpi-zero-2-w := -@ + dtb-$(CONFIG_ARCH_BCM2835) += bcm2711-rpi-400.dtb \ bcm2711-rpi-4-b.dtb \ bcm2711-rpi-cm4-io.dtb \
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 v5.17 increase in size is as follows: bcm2711-rpi-400.dtb 26481 -> 36830 bytes bcm2711-rpi-4-b.dtb 26537 -> 36886 bytes bcm2711-rpi-cm4-io.dtb 26426 -> 36945 bytes bcm2837-rpi-3-a-plus.dtb 14133 -> 19740 bytes bcm2837-rpi-3-b.dtb 14310 -> 20006 bytes bcm2837-rpi-3-b-plus.dtb 14670 -> 20474 bytes bcm2837-rpi-cm3-io3.dtb 13680 -> 19266 bytes Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> --- arch/arm64/boot/dts/broadcom/Makefile | 11 +++++++++++ 1 file changed, 11 insertions(+)