Messages in this thread Patch in this message | | | Subject | Re: [PATCHv4 27/28] firmware: Add CONFIG_BUILTIN_FIRMWARE option | From | David Woodhouse <> | Date | Wed, 28 May 2008 14:46:03 +0300 |
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More feedback... Andrew wanted the help text to be a little more... well, helpful. And Johannes wanted to add a CONFIG_BUILTIN_FIRMWARE_DIR option, which lets you just point it at /lib/firmware or somewhere else outside the kernel tree. And we fixed up a bunch of other details, like the dependencies on directories, and the fact that the .S file doesn't actually need to change when the binary blob does.
I even made the Makefile fit in 80 characters. It's going to make your brain hurt either way -- but that's normal for kernel Makefiles.
commit 4311743f8ef92ab462c06a9dd2ff8e0d735b3dae Author: David Woodhouse <dwmw2@infradead.org> Date: Fri May 23 13:58:12 2008 +0100
firmware: Add CONFIG_BUILTIN_FIRMWARE option
This allows arbitrary firmware files to be included in the static kernel where the firmware loader can find them without requiring userspace to be alive.
(Updated and CONFIG_BUILTIN_FIRMWARE_DIR added with lots of help from Johannes Berg).
Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
diff --git a/Makefile b/Makefile index 20b3235..ac2ab7e 100644 --- a/Makefile +++ b/Makefile @@ -450,7 +450,7 @@ scripts: scripts_basic include/config/auto.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/ diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index d7da109..f204ae7 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -34,6 +34,39 @@ config FW_LOADER require userspace firmware loading support, but a module built outside the kernel tree does. +config BUILTIN_FIRMWARE + string "Firmware blobs to build into the kernel binary" + depends on FW_LOADER + help + This option allows firmware to be built into the kernel, for the + cases where the user either cannot or doesn't want to provide it from + userspace at runtime (for example, when the firmware in question is + required for accessing the boot device, and the user doesn't want to + use an initrd). + + This option is a string, and takes the (space-separated) names of the + firmware files -- the same names which appear in MODULE_FIRMWARE() + and request_firmware() in the source. These files should exist under + the directory specified by the BUILTIN_FIRMWARE_DIR option, which is + by default the firmware/ subdirectory of the kernel source tree. + + So, for example, you might set CONFIG_BUILTIN_FIRMWARE="usb8388.bin", + copy the usb8388.bin file into the firmware/ directory, and build the + kernel. Then any request_firmware("usb8388.bin") will be + satisfied internally without needing to call out to userspace. + +config BUILTIN_FIRMWARE_DIR + string "Firmware blobs root directory" + depends on BUILTIN_FIRMWARE != "" + default "firmware" + help + This option controls the directory in which the kernel build system + looks for the firmware files listed in the BUILTIN_FIRMWARE option. + The default is the firmware/ directory in the kernel source tree, + but by changing this option you can point it elsewhere, such as + the /lib/firmware/ directory or another separate directory + containing firmware files. + config DEBUG_DRIVER bool "Driver Core verbose debug messages" depends on DEBUG_KERNEL diff --git a/firmware/Makefile b/firmware/Makefile new file mode 100644 index 0000000..c79bbe7 --- /dev/null +++ b/firmware/Makefile @@ -0,0 +1,86 @@ +# +# kbuild file for firmware/ +# + +# Create $(fwdir) from $(CONFIG_BUILTIN_FIRMWARE_DIR) -- if it doesn't have a +# leading /, it's relative to $(srctree). +fwdir := $(subst ",,$(CONFIG_BUILTIN_FIRMWARE_DIR)) +fwabs := $(addprefix $(srctree)/,$(filter-out /%,$(fwdir)))$(filter /%,$(fwdir)) + +fw-external-y := $(subst ",,$(CONFIG_BUILTIN_FIRMWARE)) + +firmware-y := $(fw-external-y) $(fw-shipped-y) +firmware-dirs := $(sort $(patsubst %,$(objtree)/$(obj)/%/,$(dir $(firmware-y)))) + +quiet_cmd_mkdir = MKDIR $(subst $(srctree)/,,$@) + cmd_mkdir = mkdir -p $@ + +quiet_cmd_ihex = IHEX $@ + cmd_ihex = objcopy -Iihex -Obinary $< $@ + +ifdef CONFIG_64BIT +ASM_WORD := .quad +ASM_ALIGN := 3 +else +ASM_WORD := .long +ASM_ALIGN := 2 +endif + +quiet_cmd_fwbin = MK_FW $@ + cmd_fwbin = FWNAME="$(patsubst firmware/%.S,%,$@)"; \ + FWSTR="$(subst /,_,$(subst .,_,$(patsubst \ + firmware/%.S,%,$@)))"; \ + echo "/* Generated by firmware/Makefile */" > $@;\ + echo " .section .rodata" >>$@;\ + echo " .align $(ASM_ALIGN)" >>$@;\ + echo "_fw_$${FWSTR}_bin:" >>$@;\ + echo " .incbin \"$(2)\"" >>$@;\ + echo "_fw_end:" >>$@;\ + echo " .section .rodata.str,\"aMS\",@progbits,1" >>$@;\ + echo " .align $(ASM_ALIGN)" >>$@;\ + echo "_fw_$${FWSTR}_name:" >>$@;\ + echo " .string \"$$FWNAME\"" >>$@;\ + echo " .section .builtin_fw,\"a\",@progbits" >>$@;\ + echo " .align $(ASM_ALIGN)" >>$@;\ + echo " $(ASM_WORD) _fw_$${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) + +# For the $$(dir %) trick, where we need % to be expanded first. +.SECONDEXPANSION: + +$(patsubst %,$(obj)/%.S, $(fw-shipped-y)): %: $(wordsize_deps) \ + | $(objtree)/$$(dir %) + $(call cmd,fwbin,$(patsubst %.S,%,$@)) +$(patsubst %,$(obj)/%.S, $(fw-external-y)): %: $(wordsize_deps) \ + include/config/builtin/firmware/dir.h | $(objtree)/$$(dir %) + $(call cmd,fwbin,$(fwabs)/$(patsubst $(obj)/%.S,%,$@)) + +# The .o files depend on the binaries directly; the .S files don't. +$(patsubst %,$(obj)/%.o, $(fw-shipped-y)): %.o: % +$(patsubst %,$(obj)/%.o, $(fw-external-y)): $(obj)/%.o: $(fwdir)/% + +$(obj)/%: $(obj)/%.ihex | $(objtree)/$(obj)/$$(dir %) + $(call cmd,ihex) + +$(firmware-dirs): + $(call cmd,mkdir) + +obj-y := $(patsubst %,%.o, $(firmware-y)) + +# Remove .S files and binaries created from ihex +# (during 'make clean' .config isn't included so they're all in $(fw-shipped-)) +targets := $(patsubst $(obj)/%,%, $(shell find $(obj) -name \*.S 2>/dev/null)) +targets += $(fw-shipped-) + +# Without this, built-in.o won't be created when it's empty, and the +# final vmlinux link will fail. +obj-n := dummy
-- dwmw2
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