firmware: Restore support for built-in firmware
Commit 5620a0d1aac ("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: 5620a0d1aac ("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>
diff --git a/Makefile b/Makefile
index 7e2ca49..9f86816 100644
--- a/Makefile
+++ b/Makefile
@@ -562,7 +562,7 @@
# 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/
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index f046d21..1a5f6a1 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -140,13 +140,10 @@
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
diff --git a/firmware/.gitignore b/firmware/.gitignore
new file mode 100644
index 0000000..d9c6901
--- /dev/null
+++ b/firmware/.gitignore
@@ -0,0 +1,6 @@
+*.gen.S
+*.fw
+*.bin
+*.csp
+*.dsp
+ihex2fw
diff --git a/firmware/Makefile b/firmware/Makefile
new file mode 100644
index 0000000..fa08088
--- /dev/null
+++ b/firmware/Makefile
@@ -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
