* [RFC][PATCH] kbuild: Generate symbols for DTO application in DTBs
@ 2022-04-07 11:05 Marek Vasut
2022-04-07 12:30 ` Masahiro Yamada
0 siblings, 1 reply; 3+ messages in thread
From: Marek Vasut @ 2022-04-07 11:05 UTC (permalink / raw)
To: linux-kbuild; +Cc: Marek Vasut, Masahiro Yamada
Emit symbols section in DTBs to permit symbol resolution when applying DTOs.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
---
NOTE: I am sending this as RFC, because I suspect there is a better way how
to pass extra flags to DTC during kernel build ?
Maybe from shell environment somehow ?
Or maybe b7e70391a5451 ("arm64: tegra: Enable device-tree overlay support")
is the way to go about this ?
---
arch/arm/boot/dts/Makefile | 3 +++
arch/arm64/boot/dts/Makefile | 3 +++
2 files changed, 6 insertions(+)
diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 252353fb4e3b3..2d50302d077dd 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -1,4 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
+
+DTC_FLAGS += -@
+
dtb-$(CONFIG_ARCH_ALPINE) += \
alpine-db.dtb
dtb-$(CONFIG_MACH_ARTPEC6) += \
diff --git a/arch/arm64/boot/dts/Makefile b/arch/arm64/boot/dts/Makefile
index 1ba04e31a4387..f7b3c86517a0e 100644
--- a/arch/arm64/boot/dts/Makefile
+++ b/arch/arm64/boot/dts/Makefile
@@ -1,4 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
+
+DTC_FLAGS += -@
+
subdir-y += actions
subdir-y += allwinner
subdir-y += altera
--
2.35.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RFC][PATCH] kbuild: Generate symbols for DTO application in DTBs
2022-04-07 11:05 [RFC][PATCH] kbuild: Generate symbols for DTO application in DTBs Marek Vasut
@ 2022-04-07 12:30 ` Masahiro Yamada
2022-04-10 0:07 ` Marek Vasut
0 siblings, 1 reply; 3+ messages in thread
From: Masahiro Yamada @ 2022-04-07 12:30 UTC (permalink / raw)
To: Marek Vasut, DTML; +Cc: Linux Kbuild mailing list, Rob Herring
Hi Marek.
(+CC Rob, DT ML)
On Thu, Apr 7, 2022 at 8:05 PM Marek Vasut <marex@denx.de> wrote:
>
> Emit symbols section in DTBs to permit symbol resolution when applying DTOs.
I CCed DT folks, but if I remember correctly, adding -@ globally
was NACKed because it would increase blob size for platforms that
do not need overlay.
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> ---
> NOTE: I am sending this as RFC, because I suspect there is a better way how
> to pass extra flags to DTC during kernel build ?
> Maybe from shell environment somehow ?
For local use, yes, you can add -@ from the command line.
Try this:
DTC_FLAGS=-@ make ARCH=arm64 dtbs
This is undocumented tip, but it seems to work
for the current code.
> Or maybe b7e70391a5451 ("arm64: tegra: Enable device-tree overlay support")
> is the way to go about this ?
Since commit 15d16d6dadf6947ac7f9a686c615995c5a426ce2,
adding -@ is automatic for platforms that support overlay.
If <platform>-dtbs exists, -@ is automatically added.
See arch/arm64/boot/dts/xilinx/Makefile
as an example code.
> ---
> arch/arm/boot/dts/Makefile | 3 +++
> arch/arm64/boot/dts/Makefile | 3 +++
> 2 files changed, 6 insertions(+)
>
> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> index 252353fb4e3b3..2d50302d077dd 100644
> --- a/arch/arm/boot/dts/Makefile
> +++ b/arch/arm/boot/dts/Makefile
> @@ -1,4 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> +
> +DTC_FLAGS += -@
> +
> dtb-$(CONFIG_ARCH_ALPINE) += \
> alpine-db.dtb
> dtb-$(CONFIG_MACH_ARTPEC6) += \
> diff --git a/arch/arm64/boot/dts/Makefile b/arch/arm64/boot/dts/Makefile
> index 1ba04e31a4387..f7b3c86517a0e 100644
> --- a/arch/arm64/boot/dts/Makefile
> +++ b/arch/arm64/boot/dts/Makefile
> @@ -1,4 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> +
> +DTC_FLAGS += -@
> +
> subdir-y += actions
> subdir-y += allwinner
> subdir-y += altera
> --
> 2.35.1
>
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC][PATCH] kbuild: Generate symbols for DTO application in DTBs
2022-04-07 12:30 ` Masahiro Yamada
@ 2022-04-10 0:07 ` Marek Vasut
0 siblings, 0 replies; 3+ messages in thread
From: Marek Vasut @ 2022-04-10 0:07 UTC (permalink / raw)
To: Masahiro Yamada, DTML; +Cc: Linux Kbuild mailing list, Rob Herring
On 4/7/22 14:30, Masahiro Yamada wrote:
> Hi Marek.
> (+CC Rob, DT ML)
Hi,
> On Thu, Apr 7, 2022 at 8:05 PM Marek Vasut <marex@denx.de> wrote:
>>
>> Emit symbols section in DTBs to permit symbol resolution when applying DTOs.
>
> I CCed DT folks, but if I remember correctly, adding -@ globally
> was NACKed because it would increase blob size for platforms that
> do not need overlay.
>
>
>> Signed-off-by: Marek Vasut <marex@denx.de>
>> Cc: Masahiro Yamada <masahiroy@kernel.org>
>> ---
>> NOTE: I am sending this as RFC, because I suspect there is a better way how
>> to pass extra flags to DTC during kernel build ?
>> Maybe from shell environment somehow ?
>
>
> For local use, yes, you can add -@ from the command line.
>
> Try this:
>
> DTC_FLAGS=-@ make ARCH=arm64 dtbs
>
>
> This is undocumented tip, but it seems to work
> for the current code.
This is real nice (and very much what I need), thank you.
>> Or maybe b7e70391a5451 ("arm64: tegra: Enable device-tree overlay support")
>> is the way to go about this ?
>
>
> Since commit 15d16d6dadf6947ac7f9a686c615995c5a426ce2,
> adding -@ is automatic for platforms that support overlay.
>
>
> If <platform>-dtbs exists, -@ is automatically added.
>
> See arch/arm64/boot/dts/xilinx/Makefile
> as an example code.
Is it now allowed to start upstreaming DT overlays then ?
That would be nice too.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-04-07 11:05 [RFC][PATCH] kbuild: Generate symbols for DTO application in DTBs Marek Vasut
2022-04-07 12:30 ` Masahiro Yamada
2022-04-10 0:07 ` Marek Vasut
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