| Message ID | 20220407110522.122393-1-marex@denx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC] kbuild: Generate symbols for DTO application in DTBs | expand |
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 >
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.
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
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(+)