Add multi images support

This adds the make infrastructure to build multiple SoC or
board specific images from a single barebox binary.

The basic idea is that we no longer have a single pbl, but instead
multiple pbls, one per image if necessary. Each pbl is defined
by its entry function so that each pbl can do exactly what a given
board needs. Additionally the pbls together with a self extracting
barebox binary can be encapsulated in specific image formats.

squashed in build fixes from Lucas Stach for make version >= 3.82:

Split Multimage Makefile rule in explicit and implicit parts

Fixes build with make version >=3.82

Frome the make 3.82 NEWS file:
* WARNING: Backward-incompatibility!
  In previous versions of make it was acceptable to list one or more explicit
  targets followed by one or more pattern targets in the same rule and it
  worked "as expected".  However, this was not documented as acceptable and if
  you listed any explicit targets AFTER the pattern targets, the entire rule
  would be mis-parsed.  This release removes this ability completely: make
  will generate an error message if you mix explicit and pattern targets in
  the same rule.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lucas Stach <dev@lynxeye.de>

1 files changed, 122 insertions, 0 deletions

diff --git a/images/Makefile b/images/Makefile
new file mode 100644
index 0000000000..fe1f77d407
--- /dev/null
+++ b/images/Makefile
@@ -0,0 +1,122 @@
+#
+# barebox image generation Makefile
+#
+# This Makefile generates multiple images from a common barebox image
+# and different pbl (pre bootloader) images. Optionally the result is
+# encapsulated in SoC (or SoC boot type) specific image formats.
+#
+# The basic idea here is that we generate a single barebox main binary. This
+# is compressed and prepended with a self extractor, generated as barebox.x.
+# barebox.x is then prepended with different board specific pbls. The pbls
+# are generally named after their entrypoints. So a pcm038 specific pbl will
+# generate the following files:
+#
+# start_imx27_pcm038.pbl - The ELF file, linked with the entrypoint start_imx27_pcm038
+# start_imx27_pcm038.pblb - The raw binary of the above.
+# start_imx27_pcm038.pblx - The pblb appended with barebox.x
+# start_imx27_pcm038.pbl.map - The linker map file
+# start_imx27_pcm038.pbl.s - the disassembled ELF, generated with:
+#                            make images/start_imx27_pcm038.pbl.s
+#
+# Example Makefile snippets for the i.MX51 babbage board (for readability in opposite
+# order):
+#
+## image-$(CONFIG_MACH_FREESCALE_MX51_PDK) += barebox-imx51-babbage.img
+#
+# For CONFIG_MACH_FREESCALE_MX51_PDK build barebox-imx51-babbage.img
+#
+## FILE_barebox-imx51-babbage.img = start_imx51_babbage.pblx.imximg
+#
+# barebox-imx51-babbage.img should be generated (copied) from
+# start_imx51_babbage.pblx.imximg. This copy process is only done so that we
+# can generate images with a sane name. So what we really need for this
+# board is a i.MX specific image, a .imximg
+#
+## imximage-$(CONFIG_MACH_FREESCALE_MX51_PDK) += start_imx51_babbage.pblx.imximg
+## CFG_start_imx51_babbage.pblx.imximg = $(board)/freescale-mx51-pdk/flash-header.imxcfg
+#
+# The .imximg can be generated from a .pblx using a rule specified in Makefile.imx.
+# The configfile needed for this image is specified with CFG_<filename> = <configfile>
+#
+## pblx-$(CONFIG_MACH_FREESCALE_MX51_PDK) += start_imx51_babbage
+#
+# For this image we need a pblx (self extracting barebox binary) with
+# start_imx51_babbage as entrypoint. start_imx51_babbage will be used
+# both as entrypoint and as filename
+#
+
+quiet_cmd_objcopy_bin = OBJCOPYB $@
+      cmd_objcopy_bin = $(OBJCOPY) -O binary $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
+
+pbl-lds := $(obj)/pbl.lds
+extra-y += $(pbl-lds)
+
+$(pbl-lds): $(obj)/../arch/$(ARCH)/lib/pbl.lds.S FORCE
+	$(call if_changed_dep,cpp_lds_S)
+
+quiet_cmd_elf__ ?= LD      $@
+      cmd_elf__ ?= $(LD) $(LDFLAGS) -static --gc-sections -pie		\
+		-e $(2) -Map $@.map $(LDFLAGS_$(@F)) -o $@		\
+		-T $(pbl-lds)						\
+		--start-group $(barebox-pbl-common) --end-group
+
+PBL_CPPFLAGS	+= -fdata-sections -ffunction-sections
+
+$(obj)/%.pbl: $(pbl-lds) $(barebox-pbl-common) FORCE
+	$(call if_changed,elf__,$(*F))
+
+$(obj)/%.pblb: $(obj)/%.pbl FORCE
+	$(call if_changed,objcopy_bin,$(*F))
+
+quiet_cmd_pblx ?= PBLX    $@
+      cmd_pblx ?= cat $(obj)/$(patsubst %.pblx,%.pblb,$(2)) > $@; \
+		  $(call size_append, $(obj)/barebox.x) >> $@; \
+		  cat $(obj)/barebox.x >> $@
+
+$(obj)/%.pblx: $(obj)/%.pblb $(obj)/barebox.x FORCE
+	$(call if_changed,pblx,$(@F))
+
+$(obj)/%.s: $(obj)/% FORCE
+	$(call if_changed,disasm)
+
+suffix_$(CONFIG_IMAGE_COMPRESSION_GZIP) = gzip
+suffix_$(CONFIG_IMAGE_COMPRESSION_LZO)  = lzo
+suffix_$(CONFIG_IMAGE_COMPRESSION_NONE) = shipped
+
+# barebox.z - compressed barebox binary
+# ----------------------------------------------------------------
+$(obj)/barebox.z: $(obj)/../barebox.bin FORCE
+	$(call if_changed,$(suffix_y))
+
+quiet_cmd_selfextract = COMP    $@
+      cmd_selfextract = cat $(obj)/start_uncompress.pblb > $@; \
+			$(call size_append, $<) >> $@; \
+			cat $< >> $@
+
+pblx-y += start_uncompress
+# barebox.x - self extracting barebox binary
+# ----------------------------------------------------------------
+$(obj)/barebox.x: $(obj)/barebox.z $(obj)/start_uncompress.pblb FORCE
+	$(call if_changed,selfextract)
+
+# %.img - create a copy from another file
+# ----------------------------------------------------------------
+.SECONDEXPANSION:
+$(obj)/%.img: $(obj)/$$(FILE_$$(@F))
+	$(Q)if [ -z $(FILE_$(@F)) ]; then echo "FILE_$(@F) empty!"; false; fi
+	$(call if_changed,shipped)
+
+targets += $(image-y) pbl.lds barebox.x barebox.z
+targets += $(patsubst %,%.pblx,$(pblx-y))
+targets += $(patsubst %,%.pblb,$(pblx-y))
+targets += $(patsubst %,%.pbl,$(pblx-y))
+targets += $(patsubst %,%.s,$(pblx-y))
+targets += $(imximage-y)
+
+SECONDARY: $(addprefix $(obj)/,$(targets))
+
+images: $(addprefix $(obj)/, $(image-y)) FORCE
+	@echo "images built:\n" $(patsubst %,%\\n,$(image-y))
+
+clean-files := *.pbl *.pblb *.pblx *.map start_*.imximg *.img barebox.z
+clean-files += pbl.lds