Add support for generating kernel images in the Flattened Image Tree
(.itb) format as supported by U-Boot. This format is essentially a
Flattened Device Tree binary containing images (kernels, DTBs, ramdisks)
and configurations which link those images together. The big advantages
of FIT images over the uImage format are:
- We can include FDTs in the kernel image in a way that the bootloader
can extract it & manipulate it before providing it to the kernel.
Thus we can ship FDTs as part of the kernel giving us the advantages
of being able to develop & maintain the DT within the kernel tree,
but also have the benefits of the bootloader being able to
manipulate the FDT. Example uses for this would be to inject the
kernel command line into the chosen node, or to fill in the correct
memory size.
- We can include multiple configurations in a single kernel image.
This means that a single FIT image can, given appropriate
bootloaders, be booted on different boards with the bootloader
selecting an appropriate configuration & providing the correct FDT
to the kernel.
- We can support a multitude of hashes over the data.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
arch/mips/Makefile | 8 ++++++-
arch/mips/boot/Makefile | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index efd7a9d..d968ec0 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -266,7 +266,8 @@ KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y)
KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)
bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y) \
- VMLINUX_ENTRY_ADDRESS=$(entry-y)
+ VMLINUX_ENTRY_ADDRESS=$(entry-y) \
+ PLATFORM=$(platform-y)
LDFLAGS += -m $(ld-emul)
@@ -306,6 +307,11 @@ boot-y += uImage.gz
boot-y += uImage.lzma
boot-y += uImage.lzo
endif
+boot-y += vmlinux.itb
+boot-y += vmlinux.gz.itb
+boot-y += vmlinux.bz2.itb
+boot-y += vmlinux.lzma.itb
+boot-y += vmlinux.lzo.itb
# compressed boot image targets (arch/mips/boot/compressed/)
bootz-y := vmlinuz
diff --git a/arch/mips/boot/Makefile b/arch/mips/boot/Makefile
index acb1988..ed65663 100644
--- a/arch/mips/boot/Makefile
+++ b/arch/mips/boot/Makefile
@@ -100,3 +100,60 @@ $(obj)/uImage.lzo: $(obj)/vmlinux.bin.lzo FORCE
$(obj)/uImage: $(obj)/uImage.$(suffix-y)
@ln -sf $(notdir $<) $@
@echo ' Image $@ is ready'
+
+#
+# Flattened Image Tree (.itb) images
+#
+
+targets += vmlinux.itb
+targets += vmlinux.gz.itb
+targets += vmlinux.bz2.itb
+targets += vmlinux.lzma.itb
+targets += vmlinux.lzo.itb
+
+quiet_cmd_cpp_its_S = ITS $@
+ cmd_cpp_its_S = $(CPP) $(cpp_flags) -P -C -o $@ $< \
+ -DKERNEL_NAME="\"Linux $(KERNELRELEASE)\"" \
+ -DVMLINUX_BINARY="\"$(3)\"" \
+ -DVMLINUX_COMPRESSION="\"$(2)\"" \
+ -DVMLINUX_LOAD_ADDRESS=$(VMLINUX_LOAD_ADDRESS) \
+ -DVMLINUX_ENTRY_ADDRESS=$(VMLINUX_ENTRY_ADDRESS)
+
+$(obj)/vmlinux.its: $(srctree)/arch/mips/$(PLATFORM)/vmlinux.its.S FORCE
+ $(call if_changed_dep,cpp_its_S,none,vmlinux.bin)
+
+$(obj)/vmlinux.gz.its: $(srctree)/arch/mips/$(PLATFORM)/vmlinux.its.S FORCE
+ $(call if_changed_dep,cpp_its_S,gzip,vmlinux.bin.gz)
+
+$(obj)/vmlinux.bz2.its: $(srctree)/arch/mips/$(PLATFORM)/vmlinux.its.S FORCE
+ $(call if_changed_dep,cpp_its_S,bzip2,vmlinux.bin.bz2)
+
+$(obj)/vmlinux.lzma.its: $(srctree)/arch/mips/$(PLATFORM)/vmlinux.its.S FORCE
+ $(call if_changed_dep,cpp_its_S,lzma,vmlinux.bin.lzma)
+
+$(obj)/vmlinux.lzo.its: $(srctree)/arch/mips/$(PLATFORM)/vmlinux.its.S FORCE
+ $(call if_changed_dep,cpp_its_S,lzo,vmlinux.bin.lzo)
+
+quiet_cmd_itb-image = ITB $@
+ cmd_itb-image = \
+ env PATH="$(objtree)/scripts/dtc:$(PATH)" \
+ $(CONFIG_SHELL) $(MKIMAGE) \
+ -D "-I dts -O dtb -p 500 \
+ --include $(objtree)/arch/mips \
+ --warning no-unit_address_vs_reg" \
+ -f $(2) $@
+
+$(obj)/vmlinux.itb: $(obj)/vmlinux.its $(obj)/vmlinux.bin FORCE
+ $(call if_changed,itb-image,$<)
+
+$(obj)/vmlinux.gz.itb: $(obj)/vmlinux.gz.its $(obj)/vmlinux.bin.gz FORCE
+ $(call if_changed,itb-image,$<)
+
+$(obj)/vmlinux.bz2.itb: $(obj)/vmlinux.bz2.its $(obj)/vmlinux.bin.bz2 FORCE
+ $(call if_changed,itb-image,$<)
+
+$(obj)/vmlinux.lzma.itb: $(obj)/vmlinux.lzma.its $(obj)/vmlinux.bin.lzma FORCE
+ $(call if_changed,itb-image,$<)
+
+$(obj)/vmlinux.lzo.itb: $(obj)/vmlinux.lzo.its $(obj)/vmlinux.bin.lzo FORCE
+ $(call if_changed,itb-image,$<)
--
2.9.3
