firmware: Restore support for built-in firmware

Commit 5620a0d1aa ("firmware: delete in-kernel firmware") removed the
entire firmware directory.  Unfortunately it thereby also removed the
support for built-in firmware.

This restores the ability to build firmware directly into the kernel by
pruning the original Makefile to the necessary minimum.  The default for
EXTRA_FIRMWARE_DIR is now the standard directory /lib/firmware/.

Fixes: 5620a0d1aa ("firmware: delete in-kernel firmware")
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Acked-by: Greg K-H <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Markus Trippelsdorf 2017-09-16 11:01:16 +02:00 committed by Linus Torvalds
parent 7318413077
commit df85b2d767
4 changed files with 71 additions and 5 deletions

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@ -562,7 +562,7 @@ scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
# Objects we will link into vmlinux / subdirs we need to visit
init-y := init/
drivers-y := drivers/ sound/
drivers-y := drivers/ sound/ firmware/
net-y := net/
libs-y := lib/
core-y := usr/

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@ -140,13 +140,10 @@ config EXTRA_FIRMWARE
config EXTRA_FIRMWARE_DIR
string "Firmware blobs root directory"
depends on EXTRA_FIRMWARE != ""
default "firmware"
default "/lib/firmware"
help
This option controls the directory in which the kernel build system
looks for the firmware files listed in the EXTRA_FIRMWARE option.
The default is firmware/ in the kernel source tree, but by changing
this option you can point it elsewhere, such as /lib/firmware/ or
some other directory containing the firmware files.
config FW_LOADER_USER_HELPER
bool

6
firmware/.gitignore vendored Normal file
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@ -0,0 +1,6 @@
*.gen.S
*.fw
*.bin
*.csp
*.dsp
ihex2fw

63
firmware/Makefile Normal file
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@ -0,0 +1,63 @@
#
# kbuild file for firmware/
#
# Create $(fwabs) 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 $(obj)/%.gen.S,%,$@))
# 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
targets := $(patsubst $(obj)/%,%, \
$(shell find $(obj) -name \*.gen.S 2>/dev/null))
# Without this, built-in.o won't be created when it's empty, and the
# final vmlinux link will fail.
obj- := dummy