firmware: refactor firmware/Makefile

# SPDX-License-Identifier: GPL-2.0

#

# kbuild file for firmware/

#

# Create $(fwabs) from $(CONFIG_EXTRA_FIRMWARE_DIR) -- if it doesn't have a

# Create $(fwdir) from $(CONFIG_EXTRA_FIRMWARE_DIR) -- if it doesn't have a

# leading /, it's relative to $(srctree).

fwdir := $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE_DIR))

fwabs := $(addprefix $(srctree)/,$(filter-out /%,$(fwdir)))$(filter /%,$(fwdir))

fw-external-y := $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE))

quiet_cmd_fwbin = MK_FW   $@

      cmd_fwbin = FWNAME="$(patsubst firmware/%.gen.S,%,$@)";		     \

		  FWSTR="$(subst /,_,$(subst .,_,$(subst -,_,$(patsubst	     \

				firmware/%.gen.S,%,$@))))";		     \

		  ASM_WORD=$(if $(CONFIG_64BIT),.quad,.long);		     \

		  ASM_ALIGN=$(if $(CONFIG_64BIT),3,2);			     \

		  PROGBITS=$(if $(CONFIG_ARM),%,@)progbits;		     \

		  echo "/* Generated by firmware/Makefile */"		> $@;\

		  echo "    .section .rodata"				>>$@;\

		  echo "    .p2align $${ASM_ALIGN}"			>>$@;\

		  echo "_fw_$${FWSTR}_bin:"				>>$@;\

		  echo "    .incbin \"$(2)\""				>>$@;\

		  echo "_fw_end:"					>>$@;\

		  echo "   .section .rodata.str,\"aMS\",$${PROGBITS},1"	>>$@;\

		  echo "    .p2align $${ASM_ALIGN}"			>>$@;\

		  echo "_fw_$${FWSTR}_name:"				>>$@;\

		  echo "    .string \"$$FWNAME\""			>>$@;\

		  echo "    .section .builtin_fw,\"a\",$${PROGBITS}"	>>$@;\

		  echo "    .p2align $${ASM_ALIGN}"			>>$@;\

		  echo "    $${ASM_WORD} _fw_$${FWSTR}_name"		>>$@;\

		  echo "    $${ASM_WORD} _fw_$${FWSTR}_bin"		>>$@;\

		  echo "    $${ASM_WORD} _fw_end - _fw_$${FWSTR}_bin"	>>$@;

# One of these files will change, or come into existence, whenever

# the configuration changes between 32-bit and 64-bit. The .S files

# need to change when that happens.

wordsize_deps := $(wildcard include/config/64bit.h include/config/32bit.h \

		include/config/ppc32.h include/config/ppc64.h \

		include/config/superh32.h include/config/superh64.h \

		include/config/x86_32.h include/config/x86_64.h \

		firmware/Makefile)

$(patsubst %,$(obj)/%.gen.S, $(fw-external-y)): %: $(wordsize_deps) \

		include/config/extra/firmware/dir.h

	$(call cmd,fwbin,$(fwabs)/$(patsubst $(obj)/%.gen.S,%,$@))

fwdir := $(addprefix $(srctree)/,$(filter-out /%,$(fwdir)))$(filter /%,$(fwdir))

obj-y  := $(addsuffix .gen.o, $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE)))

FWNAME    = $(patsubst $(obj)/%.gen.S,%,$@)

FWSTR     = $(subst /,_,$(subst .,_,$(subst -,_,$(FWNAME))))

ASM_WORD  = $(if $(CONFIG_64BIT),.quad,.long)

ASM_ALIGN = $(if $(CONFIG_64BIT),3,2)

PROGBITS  = $(if $(CONFIG_ARM),%,@)progbits

filechk_fwbin = { \

	echo "/* Generated by $(src)/Makefile */"		;\

	echo "    .section .rodata"				;\

	echo "    .p2align $(ASM_ALIGN)"			;\

	echo "_fw_$(FWSTR)_bin:"				;\

	echo "    .incbin \"$(fwdir)/$(FWNAME)\""		;\

	echo "_fw_end:"						;\

	echo "    .section .rodata.str,\"aMS\",$(PROGBITS),1"	;\

	echo "    .p2align $(ASM_ALIGN)"			;\

	echo "_fw_$(FWSTR)_name:"				;\

	echo "    .string \"$(FWNAME)\""			;\

	echo "    .section .builtin_fw,\"a\",$(PROGBITS)"	;\

	echo "    .p2align $(ASM_ALIGN)"			;\

	echo "    $(ASM_WORD) _fw_$(FWSTR)_name"		;\

	echo "    $(ASM_WORD) _fw_$(FWSTR)_bin"			;\

	echo "    $(ASM_WORD) _fw_end - _fw_$(FWSTR)_bin"	;\

}

$(obj)/%.gen.S: FORCE

	$(call filechk,fwbin)

# The .o files depend on the binaries directly; the .S files don't.

$(patsubst %,$(obj)/%.gen.o, $(fw-external-y)): $(obj)/%.gen.o: $(fwdir)/%

obj-y				 += $(patsubst %,%.gen.o, $(fw-external-y))

ifeq ($(KBUILD_SRC),)

# Makefile.build only creates subdirectories for O= builds, but external

# firmware might live outside the kernel source tree

_dummy := $(foreach d,$(addprefix $(obj)/,$(dir $(fw-external-y))), $(shell [ -d $(d) ] || mkdir -p $(d)))

endif

$(addprefix $(obj)/, $(obj-y)): $(obj)/%.gen.o: $(fwdir)/%

targets := $(patsubst $(obj)/%,%, \

                                $(shell find $(obj) -name \*.gen.S 2>/dev/null))