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authorLuis R. Rodriguez <mcgrof@kernel.org>2018-05-10 13:08:43 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-14 16:43:10 +0200
commit06bfd3c8ab1dbf0031022d056a90ace682f6a94c (patch)
treea6c78d27080044f797fd56411bb007c8f1ef53e0 /drivers/base/Kconfig
parent367d09824193e5a9aea98490ae0506cec8abe9c4 (diff)
downloadlinux-06bfd3c8ab1dbf0031022d056a90ace682f6a94c.tar.bz2
firmware_loader: move kconfig FW_LOADER entries to its own file
This will make it easier to track and easier to understand what components and features are part of the FW_LOADER. There are some components related to firmware which have *nothing* to do with the FW_LOADER, souch as PREVENT_FIRMWARE_BUILD. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/Kconfig')
-rw-r--r--drivers/base/Kconfig155
1 files changed, 1 insertions, 154 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 0c38df32c7fe..3e63a900b330 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -88,160 +88,7 @@ config PREVENT_FIRMWARE_BUILD
o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
-menu "Firmware loader"
-
-config FW_LOADER
- tristate "Firmware loading facility" if EXPERT
- default y
- help
- This enables the firmware loading facility in the kernel. The kernel
- will first look for built-in firmware, if it has any. Next, it will
- look for the requested firmware in a series of filesystem paths:
-
- o firmware_class path module parameter or kernel boot param
- o /lib/firmware/updates/UTS_RELEASE
- o /lib/firmware/updates
- o /lib/firmware/UTS_RELEASE
- o /lib/firmware
-
- Enabling this feature only increases your kernel image by about
- 828 bytes, enable this option unless you are certain you don't
- need firmware.
-
- You typically want this built-in (=y) but you can also enable this
- as a module, in which case the firmware_class module will be built.
- You also want to be sure to enable this built-in if you are going to
- enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
-
-if FW_LOADER
-
-config EXTRA_FIRMWARE
- string "Build named firmware blobs into the kernel binary"
- help
- Device drivers which require firmware can typically deal with
- having the kernel load firmware from the various supported
- /lib/firmware/ paths. This option enables you to build into the
- kernel firmware files. Built-in firmware searches are preceded
- over firmware lookups using your filesystem over the supported
- /lib/firmware paths documented on CONFIG_FW_LOADER.
-
- This may be useful for testing or if the firmware is required early on
- in boot and cannot rely on the firmware being placed in an initrd or
- initramfs.
-
- This option is a string and takes the (space-separated) names of the
- firmware files -- the same names that appear in MODULE_FIRMWARE()
- and request_firmware() in the source. These files should exist under
- the directory specified by the EXTRA_FIRMWARE_DIR option, which is
- /lib/firmware by default.
-
- For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
- the usb8388.bin file into /lib/firmware, and build the kernel. Then
- any request_firmware("usb8388.bin") will be satisfied internally
- inside the kernel without ever looking at your filesystem at runtime.
-
- WARNING: If you include additional firmware files into your binary
- kernel image that are not available under the terms of the GPL,
- then it may be a violation of the GPL to distribute the resulting
- image since it combines both GPL and non-GPL work. You should
- consult a lawyer of your own before distributing such an image.
-
-config EXTRA_FIRMWARE_DIR
- string "Firmware blobs root directory"
- depends on EXTRA_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.
-
-config FW_LOADER_USER_HELPER
- bool "Enable the firmware sysfs fallback mechanism"
- help
- This option enables a sysfs loading facility to enable firmware
- loading to the kernel through userspace as a fallback mechanism
- if and only if the kernel's direct filesystem lookup for the
- firmware failed using the different /lib/firmware/ paths, or the
- path specified in the firmware_class path module parameter, or the
- firmware_class path kernel boot parameter if the firmware_class is
- built-in. For details on how to work with the sysfs fallback mechanism
- refer to Documentation/driver-api/firmware/fallback-mechanisms.rst.
-
- The direct filesystem lookup for firmware is always used first now.
-
- If the kernel's direct filesystem lookup for firmware fails to find
- the requested firmware a sysfs fallback loading facility is made
- available and userspace is informed about this through uevents.
- The uevent can be suppressed if the driver explicitly requested it,
- this is known as the driver using the custom fallback mechanism.
- If the custom fallback mechanism is used userspace must always
- acknowledge failure to find firmware as the timeout for the fallback
- mechanism is disabled, and failed requests will linger forever.
-
- This used to be the default firmware loading facility, and udev used
- to listen for uvents to load firmware for the kernel. The firmware
- loading facility functionality in udev has been removed, as such it
- can no longer be relied upon as a fallback mechanism. Linux no longer
- relies on or uses a fallback mechanism in userspace. If you need to
- rely on one refer to the permissively licensed firmwared:
-
- https://github.com/teg/firmwared
-
- Since this was the default firmware loading facility at one point,
- old userspace may exist which relies upon it, and as such this
- mechanism can never be removed from the kernel.
-
- You should only enable this functionality if you are certain you
- require a fallback mechanism and have a userspace mechanism ready to
- load firmware in case it is not found. One main reason for this may
- be if you have drivers which require firmware built-in and for
- whatever reason cannot place the required firmware in initramfs.
- Another reason kernels may have this feature enabled is to support a
- driver which explicitly relies on this fallback mechanism. Only two
- drivers need this today:
-
- o CONFIG_LEDS_LP55XX_COMMON
- o CONFIG_DELL_RBU
-
- Outside of supporting the above drivers, another reason for needing
- this may be that your firmware resides outside of the paths the kernel
- looks for and cannot possibly be specified using the firmware_class
- path module parameter or kernel firmware_class path boot parameter
- if firmware_class is built-in.
-
- A modern use case may be to temporarily mount a custom partition
- during provisioning which is only accessible to userspace, and then
- to use it to look for and fetch the required firmware. Such type of
- driver functionality may not even ever be desirable upstream by
- vendors, and as such is only required to be supported as an interface
- for provisioning. Since udev's firmware loading facility has been
- removed you can use firmwared or a fork of it to customize how you
- want to load firmware based on uevents issued.
-
- Enabling this option will increase your kernel image size by about
- 13436 bytes.
-
- If you are unsure about this, say N here, unless you are Linux
- distribution and need to support the above two drivers, or you are
- certain you need to support some really custom firmware loading
- facility in userspace.
-
-config FW_LOADER_USER_HELPER_FALLBACK
- bool "Force the firmware sysfs fallback mechanism when possible"
- depends on FW_LOADER_USER_HELPER
- help
- Enabling this option forces a sysfs userspace fallback mechanism
- to be used for all firmware requests which explicitly do not disable a
- a fallback mechanism. Firmware calls which do prohibit a fallback
- mechanism is request_firmware_direct(). This option is kept for
- backward compatibility purposes given this precise mechanism can also
- be enabled by setting the proc sysctl value to true:
-
- /proc/sys/kernel/firmware_config/force_sysfs_fallback
-
- If you are unsure about this, say N here.
-
-endif # FW_LOADER
-endmenu
+source "drivers/base/firmware_loader/Kconfig"
config WANT_DEV_COREDUMP
bool