[PATCH mips-next 2/2] mips: boot: add support for self-extracting FIT images (vmlinuz.itb)

From: Alexander Lobakin
Date: Sun Nov 01 2020 - 10:13:31 EST


Commit c3e2ee657418 ("MIPS: generic: Add support for zboot") added
support for self-extracting images to Generic MIPS. However, the
intended way to boot Generic MIPS kernels is using FIT Images and
UHI boot protocol, but currently there's no way to make self-extracting
FIT Image (only legacy uzImages).
Add a target for this named "vmlinuz.itb", which will consist of
vmlinuz.bin and selected DT blobs. It will allow to have the advantages
of both UHI and self-extracting images.

Signed-off-by: Alexander Lobakin <alobakin@xxxxx>
---
arch/mips/Makefile | 1 +
arch/mips/boot/compressed/Makefile | 48 ++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+)

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 622ee83dbb9b..cd4343edeb11 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -347,6 +347,7 @@ bootz-y += vmlinuz.srec
ifeq ($(shell expr $(zload-y) \< 0xffffffff80000000 2> /dev/null), 0)
bootz-y += uzImage.bin
endif
+bootz-y += vmlinuz.itb

#
# Some machines like the Indy need 32-bit ELF binaries for booting purposes.
diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
index fa2c1e1b303f..4c3bc7e3d56d 100644
--- a/arch/mips/boot/compressed/Makefile
+++ b/arch/mips/boot/compressed/Makefile
@@ -172,3 +172,51 @@ targets += ../uzImage.bin

$(objboot)/uzImage.bin: $(objboot)/vmlinuz.bin FORCE
$(call if_changed,uimage,none)
+
+#
+# Flattened Image Tree (.itb) image
+#
+
+ifeq ($(ADDR_BITS),32)
+itb_addr_cells = 1
+endif
+ifeq ($(ADDR_BITS),64)
+itb_addr_cells = 2
+endif
+
+targets += ../vmlinuz.its.S
+
+quiet_cmd_its_cat = CAT $@
+ cmd_its_cat = cat $(real-prereqs) >$@
+
+$(objboot)/vmlinuz.its.S: $(addprefix $(srctree)/arch/mips/$(PLATFORM)/,$(ITS_INPUTS)) FORCE
+ $(call if_changed,its_cat)
+
+targets += ../vmlinuz.its
+
+quiet_cmd_cpp_its_S = ITS $@
+ cmd_cpp_its_S = $(CPP) -P -C -o $@ $< \
+ -DKERNEL_NAME="\"Linux $(KERNELRELEASE)\"" \
+ -DVMLINUX_BINARY="\"$(2)\"" \
+ -DVMLINUX_COMPRESSION="\"none\"" \
+ -DVMLINUX_LOAD_ADDRESS=$(VMLINUZ_LOAD_ADDRESS) \
+ -DVMLINUX_ENTRY_ADDRESS=$(VMLINUZ_LOAD_ADDRESS) \
+ -DADDR_BITS=$(ADDR_BITS) \
+ -DADDR_CELLS=$(itb_addr_cells)
+
+$(objboot)/vmlinuz.its: $(objboot)/vmlinuz.its.S FORCE
+ $(call if_changed,cpp_its_S,vmlinuz.bin)
+
+targets += ../vmlinuz.itb
+
+quiet_cmd_itb-image = ITB $@
+ cmd_itb-image = \
+ env PATH="$(objtree)/scripts/dtc:$(PATH)" \
+ $(BASH) $(MKIMAGE) \
+ -D "-I dts -O dtb -p 500 \
+ --include $(objtree)/arch/mips \
+ --warning no-unit_address_vs_reg" \
+ -f $(2) $@
+
+$(objboot)/vmlinuz.itb: $(objboot)/vmlinuz.its $(objboot)/vmlinuz.bin FORCE
+ $(call if_changed,itb-image,$<)
--
2.29.2