Re: [PATCH] powerpc: make the padding for the device tree a configurable option
From: Benjamin Herrenschmidt <hidden>
Date: 2010-05-19 21:20:13
Also in:
linuxppc-dev
On Wed, 2010-05-19 at 14:53 -0500, Timur Tabi wrote:
Add the DTS_PADDING Kconfig option, which allows users and board defconfig files to specify a padding value when compiling device trees. When a device tree source (DTS) is compiled into a binary (DTB), a hard-coded padding of 1024 bytes is used (i.e. dtc command-line parameter "-p 1024"). Although this has worked so far, it may not be sufficient in the future for some boards. Newer versions of U-boot perform more and more fixup on the device tree, and eventually it will run out. So to accommodate future boards where more padding is needed, we make the option for the -p parameter configurable.
Can't u-boot just allocate more space ? Ben.
quoted hunk
Signed-off-by: Timur Tabi <redacted> --- arch/powerpc/boot/Makefile | 4 ++-- arch/powerpc/platforms/Kconfig | 13 +++++++++++++ 2 files changed, 15 insertions(+), 2 deletions(-)diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile index bb2465b..750fa6b 100644 --- a/arch/powerpc/boot/Makefile +++ b/arch/powerpc/boot/Makefile@@ -35,7 +35,7 @@ endif BOOTCFLAGS += -I$(obj) -I$(srctree)/$(obj) -DTS_FLAGS ?= -p 1024 +DTS_FLAGS ?= -p ${CONFIG_DTS_PADDING} $(obj)/4xx.o: BOOTCFLAGS += -mcpu=405 $(obj)/ebony.o: BOOTCFLAGS += -mcpu=405@@ -331,7 +331,7 @@ $(obj)/treeImage.%: vmlinux $(obj)/%.dtb $(wrapperbits) # Rule to build device tree blobs DTC = $(objtree)/scripts/dtc/dtc -$(obj)/%.dtb: $(dtstree)/%.dts +$(obj)/%.dtb: $(dtstree)/%.dts $(srctree)/.config $(DTC) -O dtb -o $(obj)/$*.dtb -b 0 $(DTS_FLAGS) $(dtstree)/$*.dts # If there isn't a platform selected then just strip the vmlinux.diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig index d1663db..2b0a9c3 100644 --- a/arch/powerpc/platforms/Kconfig +++ b/arch/powerpc/platforms/Kconfig@@ -41,6 +41,19 @@ config PPC_OF_BOOT_TRAMPOLINE In case of doubt, say Y +config DTS_PADDING + int "Padding for the device tree binary" + default 1024 + help + Specify the padding value to be used when compiling a DTS (device + tree source) file into a DTB (device tree binary). The padding is + used to ensure enough space for any additional nodes and properties + that the boot loader adds during fix-up. If your boot loader + complains about lack of space during fix-up, try increasing this + value. + + If unsure, leave this value at the default. + config UDBG_RTAS_CONSOLE bool "RTAS based debug console" depends on PPC_RTAS