microblaze: support U-BOOT image format

Two version are generated.
linux.bin.ub which is created from linux.bin file
and
simpleImage.<dts>.ub which is created from stripped simpleImage.<dts> file

Load address and entry point is for microblaze first instruction
which is CONFIG_KERNEL_BASE_ADDR variable.

There is possible for simpleImage format parse _start symbol too.

simpleImage.<dts> is still stripped elf file

I cleared simpleImage.<dts>.unstrip file because there are so big.
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/boot/Makefile

@@ -2,11 +2,13 @@
 # arch/microblaze/boot/Makefile
 #
 
+MKIMAGE := $(srctree)/scripts/mkuboot.sh
+
 obj-y += linked_dtb.o
 
 targets := linux.bin linux.bin.gz simpleImage.%
 
-OBJCOPYFLAGS_linux.bin  := -O binary
+OBJCOPYFLAGS := -O binary
 
 # Where the DTS files live
 dtstree         := $(srctree)/$(src)/dts
@@ -24,6 +26,7 @@ $(obj)/linux.bin: vmlinux FORCE
 	[ -n $(CONFIG_INITRAMFS_SOURCE) ] && [ ! -e $(CONFIG_INITRAMFS_SOURCE) ] && \
 	touch $(CONFIG_INITRAMFS_SOURCE) || echo "No CPIO image"
 	$(call if_changed,objcopy)
+	$(call if_changed,uimage)
 	@echo 'Kernel: $@ is ready' ' (#'`cat .version`')'
 
 $(obj)/linux.bin.gz: $(obj)/linux.bin FORCE
@@ -36,8 +39,16 @@ quiet_cmd_cp = CP      $< $@$2
 quiet_cmd_strip = STRIP   $@
       cmd_strip = $(STRIP) -K _start -K _end -K __log_buf -K _fdt_start vmlinux -o $@
 
+quiet_cmd_uimage = UIMAGE  $@.ub
+      cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A microblaze -O linux -T kernel \
+                   -C none -n 'Linux-$(KERNELRELEASE)' \
+                   -a $(CONFIG_KERNEL_BASE_ADDR) -e $(CONFIG_KERNEL_BASE_ADDR) \
+                   -d $@ $@.ub
+
 $(obj)/simpleImage.%: vmlinux FORCE
 	$(call if_changed,cp,.unstrip)
+	$(call if_changed,objcopy)
+	$(call if_changed,uimage)
 	$(call if_changed,strip)
 	@echo 'Kernel: $@ is ready' ' (#'`cat .version`')'
 
@@ -53,4 +64,4 @@ $(obj)/%.dtb: $(dtstree)/%.dts FORCE
 
 clean-kernel += linux.bin linux.bin.gz simpleImage.*
 
-clean-files += *.dtb
+clean-files += *.dtb simpleImage.*.unstrip