linux: Fix appended DTB image generation

Hello,

What initially prompted this short series is the oldest patch currently sitting in patchwork, i.e
http://patchwork.ozlabs.org/patch/394002/. In this patch, Guido Mart?nez wanted to fix a problem in our implementation of the appended DTB image generation: we are concatenating over and over again the DTB at the end of the same file, so that if you do "make linux-rebuild" multiple times, your kernel image ends up having your DTB concatenated multiple times to it. This is because we do the appending "in place", directly on zImage.

To solve this problem, this series moves to generating the appended image under a different name: zImage.<dtb> (or uImage.<dtb> if the uImage format is used).

But since this naming allows to generate *multiple* appended DTB images (which was forbidden until now), we take this opportunity to make such a thing possible.

This is all done in the last patch of this series, the two first patches being merely preparation work for the last patch.

Please help get rid of the oldest patch in patchwork by reviewing/testing this series!

Best regards,

Thomas

Thomas Petazzoni (3):
linux: de-duplicate DTB and Linux image installation
linux: only install the DTBs when not in appended DTB mode
linux: don't build appended DTB image in place and support multiple
images

 linux/linux.mk | 70 ++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 39 insertions(+), 31 deletions(-)

2.6.2

Currently, the LINUX_INSTALL_DTB and LINUX_INSTALL_DTB_TARGET macros are exactly the same, except for the target directory.

Similarly, LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET and LINUX_INSTALL_IMAGES_CMDS are copying the kernel image, just to a different place (and with a different strategy).

As a preparation for future additions, this commit de-duplicate this code:

- LINUX_INSTALL_DTB becomes a make macro that takes one argument: the destination directory.

- LINUX_INSTALL_IMAGE is a new make macro that also takes on
argument: the destination directory.

Both macros are used by LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET and LINUX_INSTALL_IMAGES_CMDS to respectively install to the target directory and the images directory.

---
 linux/linux.mk | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

index 6c7ecfc..149bd69 100644
@@ -236,14 +236,7 @@ define LINUX_INSTALL_DTB
 	cp $(addprefix \
 		$(KERNEL_ARCH_PATH)/boot/$(if $(wildcard \
 		$(addprefix $(KERNEL_ARCH_PATH)/boot/dts/,$(KERNEL_DTBS))),dts/),$(KERNEL_DTBS)) \
-		$(BINARIES_DIR)/
-endef
-define LINUX_INSTALL_DTB_TARGET
-	# dtbs moved from arch/<ARCH>/boot to arch/<ARCH>/boot/dts since 3.8-rc1
-	cp $(addprefix \
-		$(KERNEL_ARCH_PATH)/boot/$(if $(wildcard \
-		$(addprefix $(KERNEL_ARCH_PATH)/boot/dts/,$(KERNEL_DTBS))),dts/),$(KERNEL_DTBS)) \
-		$(TARGET_DIR)/boot/
+		$(1)
 endef
 endif
 endif

@@ -284,11 +277,14 @@ define LINUX_BUILD_CMDS
 	$(LINUX_APPEND_DTB)
 endef
 
+define LINUX_INSTALL_IMAGE
+	$(INSTALL) -m 0644 -D $(LINUX_IMAGE_PATH) $(1)/$(LINUX_IMAGE_NAME)
+endef
 
 ifeq ($(BR2_LINUX_KERNEL_INSTALL_TARGET),y)
 define LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET
-	install -m 0644 -D $(LINUX_IMAGE_PATH) $(TARGET_DIR)/boot/$(LINUX_IMAGE_NAME)
-	$(LINUX_INSTALL_DTB_TARGET)
+	$(call LINUX_INSTALL_IMAGE,$(TARGET_DIR)/boot)
+	$(call LINUX_INSTALL_DTB,$(TARGET_DIR)/boot)
 endef
 endif
 

@@ -302,8 +298,8 @@ endef
 
 
 define LINUX_INSTALL_IMAGES_CMDS
-	cp $(LINUX_IMAGE_PATH) $(BINARIES_DIR)
-	$(LINUX_INSTALL_DTB)
+	$(call LINUX_INSTALL_IMAGE,$(BINARIES_DIR))
+	$(call LINUX_INSTALL_DTB,$(BINARIES_DIR))
 endef
 
 define LINUX_INSTALL_TARGET_CMDS

2.6.2

When you're using the "appended DTB" mode, the Device Tree blob gets appended to your kernel image, so there is no point in installing both the DTB and the kernel image to the images or target directories, installing the kernel image itself is sufficient.

Therefore, this commit disables the definition of LINUX_INSTALL_DTB when appended DTB is used.

---
 linux/linux.mk | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

index 149bd69..59e1bb4 100644
@@ -231,6 +231,7 @@ ifeq ($(BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT),)
 define LINUX_BUILD_DTB
 	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(KERNEL_DTBS)
 endef
+ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),)
 define LINUX_INSTALL_DTB
 	# dtbs moved from arch/<ARCH>/boot to arch/<ARCH>/boot/dts since 3.8-rc1
 	cp $(addprefix \

@@ -238,8 +239,9 @@ define LINUX_INSTALL_DTB
 		$(addprefix $(KERNEL_ARCH_PATH)/boot/dts/,$(KERNEL_DTBS))),dts/),$(KERNEL_DTBS)) \
 		$(1)
 endef
-endif
-endif
+endif # BR2_LINUX_KERNEL_APPENDED_DTB
+endif # BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT
+endif # BR2_LINUX_KERNEL_DTS_SUPPORT
 
 ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
 # dtbs moved from arch/$ARCH/boot to arch/$ARCH/boot/dts since 3.8-rc1

2.6.2

Currently, the linux.mk logic for appended DTB image does the appending of the DTB in place, directly at the end of the zImage using a >> sign. This is incorrect because if you run "make linux-rebuild" multiple times, you get the DTB appended over and over again to the image.

Since keeping the 'zImage' or 'uImage' name for the appended DTB image is not very clear, this commit moves to using the 'zImage.<dtb>' and 'uImage.<dtb>' format. This way, we can clearly distinguish the original image from the appended one.

In addition, this naming scheme easily allows to generate *multiple* appended DTB images: from one zImage, you can generate multiple zImage.<dtb> for several DTBs, and then generate (if requested) the corresponding uImage.<dtb>.

To achieve this, this commit:

- Changes the definition of LINUX_APPENDED_DTB to iterate over $(KERNEL_DTS_NAME), and generate a zImage.<dtb> image for each of them.

- Changes the addition of LINUX_APPENDED_DTB for appended uImage to also iterate over $(KERNEL_DTS_NAME).

- Provide a different implementation of LINUX_INSTALL_IMAGE which installs all the appended DTB images (but not the bare image)

- Remove the checks that verified that only one DT name is passed when appended DTB is used, since we now support generating multiple DT images.

Some of the tested configuration:

- Normal uImage with several DTBs

BR2_LINUX_KERNEL_DEFCONFIG="mvebu_v7"
BR2_LINUX_KERNEL_UIMAGE=y
BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x200000" BR2_LINUX_KERNEL_DTS_SUPPORT=y BR2_LINUX_KERNEL_INTREE_DTS_NAME="armada-xp-matrix armada-xp-gp armada-370-mirabox"

Contents of output/images/:

armada-370-mirabox.dtb armada-xp-gp.dtb armada-xp-matrix.dtb uImage

- Normal zImage with several DTBs

BR2_LINUX_KERNEL_DEFCONFIG="mvebu_v7"
BR2_LINUX_KERNEL_ZIMAGE=y
BR2_LINUX_KERNEL_DTS_SUPPORT=y BR2_LINUX_KERNEL_INTREE_DTS_NAME="armada-xp-matrix armada-xp-gp armada-370-mirabox"

Contents of output/images:

armada-370-mirabox.dtb armada-xp-gp.dtb armada-xp-matrix.dtb zImage

- Appended uImage with several DTBs:

BR2_LINUX_KERNEL_DEFCONFIG="mvebu_v7" BR2_LINUX_KERNEL_APPENDED_UIMAGE=y BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x200000" BR2_LINUX_KERNEL_INTREE_DTS_NAME="armada-xp-matrix armada-xp-gp armada-370-mirabox"

Contents of output/images:

uImage.armada-370-mirabox uImage.armada-xp-gp uImage.armada-xp-matrix

- Appended zImage with several DTBs:

BR2_LINUX_KERNEL_DEFCONFIG="mvebu_v7" BR2_LINUX_KERNEL_APPENDED_ZIMAGE=y BR2_LINUX_KERNEL_INTREE_DTS_NAME="armada-xp-matrix armada-xp-gp armada-370-mirabox"

Contents of output/images:

zImage.armada-370-mirabox zImage.armada-xp-gp zImage.armada-xp-matrix

In all configurations, the contents of output/target/boot/ was the same if BR2_LINUX_KERNEL_INSTALL_TARGET=y.

---
 linux/linux.mk | 44 +++++++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 17 deletions(-)

index 59e1bb4..297ef83 100644
@@ -246,11 +246,15 @@ endif # BR2_LINUX_KERNEL_DTS_SUPPORT
 ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
 # dtbs moved from arch/$ARCH/boot to arch/$ARCH/boot/dts since 3.8-rc1
 define LINUX_APPEND_DTB
-	if [ -e $(KERNEL_ARCH_PATH)/boot/$(KERNEL_DTS_NAME).dtb ]; then \
-		cat $(KERNEL_ARCH_PATH)/boot/$(KERNEL_DTS_NAME).dtb; \
-	else \
-		cat $(KERNEL_ARCH_PATH)/boot/dts/$(KERNEL_DTS_NAME).dtb; \
-	fi >> $(KERNEL_ARCH_PATH)/boot/zImage
+	(cd $(KERNEL_ARCH_PATH)/boot; \
+		for dtb in $(KERNEL_DTS_NAME); do \
+			if test -e $${dtb}.dtb ; then \
+				dtbpath=$${dtb}.dtb ; \
+			else \
+				dtbpath=dts/$${dtb}.dtb ; \
+			fi ; \
+			cat zImage $${dtbpath} > zImage.$${dtb} || exit 1; \
+		done)
 endef
 ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
 # We need to generate a new u-boot image that takes into

@@ -258,11 +262,14 @@ ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
 # of the image. To do so, we first need to retrieve both load
 # address and entry point for the kernel from the already
 # generate uboot image before using mkimage -l.
-LINUX_APPEND_DTB += $(sep) MKIMAGE_ARGS=`$(MKIMAGE) -l $(LINUX_IMAGE_PATH) |\
+LINUX_APPEND_DTB += ; \
+	MKIMAGE_ARGS=`$(MKIMAGE) -l $(LINUX_IMAGE_PATH) |\
 	sed -n -e 's/Image Name:[ ]*\(.*\)/-n \1/p' -e 's/Load Address:/-a/p' -e 's/Entry Point:/-e/p'`; \
-	$(MKIMAGE) -A $(MKIMAGE_ARCH) -O linux \
-	-T kernel -C none $${MKIMAGE_ARGS} \
-	-d $(KERNEL_ARCH_PATH)/boot/zImage $(LINUX_IMAGE_PATH);
+	for dtb in $(KERNEL_DTS_NAME); do \
+		$(MKIMAGE) -A $(MKIMAGE_ARCH) -O linux \
+			-T kernel -C none $${MKIMAGE_ARGS} \
+			-d $(KERNEL_ARCH_PATH)/boot/zImage.$${dtb} $(LINUX_IMAGE_PATH).$${dtb}; \
+	done
 endif
 endif
 

@@ -279,9 +286,20 @@ define LINUX_BUILD_CMDS
 	$(LINUX_APPEND_DTB)
 endef
 
+ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
+# When a DTB was appended, install the potential several images with
+# appended DTBs.
+define LINUX_INSTALL_IMAGE
+	mkdir -p $(1)
+	cp $(KERNEL_ARCH_PATH)/boot/$(LINUX_IMAGE_NAME).* $(1)
+endef
+else
+# Otherwise, just install the unique image generated by the kernel
+# build process.
 define LINUX_INSTALL_IMAGE
 	$(INSTALL) -m 0644 -D $(LINUX_IMAGE_PATH) $(1)/$(LINUX_IMAGE_NAME)
 endef
+endif
 
 ifeq ($(BR2_LINUX_KERNEL_INSTALL_TARGET),y)
 define LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET

@@ -290,7 +308,6 @@ define LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET
 endef
 endif
 
-
 define LINUX_INSTALL_HOST_TOOLS
 	# Installing dtc (device tree compiler) as host tool, if selected
 	if grep -q "CONFIG_DTC=y" $(@D)/.config; then 	\

@@ -377,13 +394,6 @@ $(error No kernel device tree source specified, check your \
 BR2_LINUX_KERNEL_USE_INTREE_DTS / BR2_LINUX_KERNEL_USE_CUSTOM_DTS settings)
 endif
 
-ifeq ($(BR2_LINUX_KERNEL_APPENDED_DTB),y)
-ifneq ($(words $(KERNEL_DTS_NAME)),1)
-$(error Kernel with appended device tree needs exactly one DTS source. \
-	Check BR2_LINUX_KERNEL_INTREE_DTS_NAME or BR2_LINUX_KERNEL_CUSTOM_DTS_PATH.)
-endif
-endif
-
 endif # BR_BUILDING
 
 $(eval $(kconfig-package))

2.6.2

Hi,

Thanks for the testing!

Don't we have readme's and u-boot boot scripts expecting uImage instead of uImage.<dtb>? I guess if nothing else we need to update the readme's to tell people to rename the file when copying to the sd card or whatever.

Other than that the series look good to me!

Bye, Peter Korsgaard

Hello,

Series applied. I didn't get much review, except Peter saying "Other than that the series look good to me!", and the series has been around for 2+ months, so I applied.

Thomas

Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com