xtensa: clean up bootable image build targets

Currently xtensa uses 'zImage' as a synonym of 'all', but in fact xtensa
supports three targets: 'Image' (ELF image with reset vector), 'zImage'
(compressed redboot image) and 'uImage' (U-Boot image).
Provide separate 'Image', 'zImage' and 'uImage' make targets that only
build corresponding image type. Make 'all' build all images appropriate
for a platform.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/Makefile

@@ -93,11 +93,7 @@ endif
 
 boot		:= arch/xtensa/boot
 
-all: zImage
-
-bzImage : zImage
-
-zImage: vmlinux
+all Image zImage uImage: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $@
 
 %.dtb:
@@ -107,6 +103,8 @@ dtbs: scripts
 	$(Q)$(MAKE) $(build)=$(boot)/dts
 
 define archhelp
+  @echo '* Image       - Kernel ELF image with reset vector'
   @echo '* zImage      - Compressed kernel image (arch/xtensa/boot/images/zImage.*)'
+  @echo '* uImage      - U-Boot wrapped image'
   @echo '  dtbs        - Build device tree blobs for enabled boards'
 endef

arch/xtensa/boot/Makefile

@@ -21,13 +21,16 @@ subdir-y	:= lib
 
 # Subdirs for the boot loader(s)
 
-bootdir-$(CONFIG_XTENSA_PLATFORM_ISS)	 += boot-elf
-bootdir-$(CONFIG_XTENSA_PLATFORM_XT2000) += boot-redboot boot-elf boot-uboot
-bootdir-$(CONFIG_XTENSA_PLATFORM_XTFPGA) += boot-redboot boot-elf boot-uboot
+boot-$(CONFIG_XTENSA_PLATFORM_ISS)    += Image
+boot-$(CONFIG_XTENSA_PLATFORM_XT2000) += Image zImage uImage
+boot-$(CONFIG_XTENSA_PLATFORM_XTFPGA) += Image zImage uImage
 
-zImage Image: $(bootdir-y)
+all: $(boot-y)
+Image: boot-elf
+zImage: boot-redboot
+uImage: $(obj)/uImage
 
-$(bootdir-y): $(addprefix $(obj)/,$(subdir-y)) \
+boot-elf boot-redboot: $(addprefix $(obj)/,$(subdir-y)) \
 		       $(addprefix $(obj)/,$(host-progs))
 	$(Q)$(MAKE) $(build)=$(obj)/$@ $(MAKECMDGOALS)
 
@@ -41,4 +44,10 @@ vmlinux.bin.gz: vmlinux.bin FORCE
 
 boot-elf: vmlinux.bin
 boot-redboot: vmlinux.bin.gz
-boot-uboot: vmlinux.bin.gz
+
+UIMAGE_LOADADDR = $(CONFIG_KERNEL_LOAD_ADDRESS)
+UIMAGE_COMPRESSION = gzip
+
+$(obj)/uImage: vmlinux.bin.gz FORCE
+	$(call if_changed,uimage)
+	$(Q)$(kecho) '  Kernel: $@ is ready'

arch/xtensa/boot/boot-elf/Makefile

@@ -31,4 +31,4 @@ $(obj)/../Image.elf: $(obj)/Image.o $(obj)/boot.lds
 		-o $@ $(obj)/Image.o
 	$(Q)$(kecho) '  Kernel: $@ is ready'
 
-zImage:	$(obj)/../Image.elf
+all Image: $(obj)/../Image.elf

arch/xtensa/boot/boot-redboot/Makefile

@@ -32,4 +32,4 @@ $(obj)/../zImage.redboot: $(obj)/zImage.elf
 	$(Q)$(OBJCOPY) -S -O binary $< $@
 	$(Q)$(kecho) '  Kernel: $@ is ready'
 
-zImage: $(obj)/../zImage.redboot
+all zImage: $(obj)/../zImage.redboot

arch/xtensa/boot/boot-uboot/Makefile

-#
-# This file is subject to the terms and conditions of the GNU General Public
-# License.  See the file "COPYING" in the main directory of this archive
-# for more details.
-#
-
-UIMAGE_LOADADDR = $(CONFIG_KERNEL_LOAD_ADDRESS)
-UIMAGE_COMPRESSION = gzip
-
-$(obj)/../uImage: vmlinux.bin.gz FORCE
-	$(call if_changed,uimage)
-	$(Q)$(kecho) '  Kernel: $@ is ready'
-
-zImage: $(obj)/../uImage