drivers/base/Kconfig

   1 menu "Generic Driver Options"
   2
   3 config UEVENT_HELPER_PATH
   4         string "path to uevent helper"
   5         depends on HOTPLUG
   6         default ""
   7         help
   8           Path to uevent helper program forked by the kernel for
   9           every uevent.
  10           Before the switch to the netlink-based uevent source, this was
  11           used to hook hotplug scripts into kernel device events. It
  12           usually pointed to a shell script at /sbin/hotplug.
  13           This should not be used today, because usual systems create
  14           many events at bootup or device discovery in a very short time
  15           frame. One forked process per event can create so many processes
  16           that it creates a high system load, or on smaller systems
  17           it is known to create out-of-memory situations during bootup.
  18
  19 config DEVTMPFS
  20         bool "Maintain a devtmpfs filesystem to mount at /dev"
  21         depends on HOTPLUG
  22         help
  23           This creates a tmpfs/ramfs filesystem instance early at bootup.
  24           In this filesystem, the kernel driver core maintains device
  25           nodes with their default names and permissions for all
  26           registered devices with an assigned major/minor number.
  27           Userspace can modify the filesystem content as needed, add
  28           symlinks, and apply needed permissions.
  29           It provides a fully functional /dev directory, where usually
  30           udev runs on top, managing permissions and adding meaningful
  31           symlinks.
  32           In very limited environments, it may provide a sufficient
  33           functional /dev without any further help. It also allows simple
  34           rescue systems, and reliably handles dynamic major/minor numbers.
  35
  36           Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
  37           file system will be used instead.
  38
  39 config DEVTMPFS_MOUNT
  40         bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
  41         depends on DEVTMPFS
  42         help
  43           This will instruct the kernel to automatically mount the
  44           devtmpfs filesystem at /dev, directly after the kernel has
  45           mounted the root filesystem. The behavior can be overridden
  46           with the commandline parameter: devtmpfs.mount=0|1.
  47           This option does not affect initramfs based booting, here
  48           the devtmpfs filesystem always needs to be mounted manually
  49           after the roots is mounted.
  50           With this option enabled, it allows to bring up a system in
  51           rescue mode with init=/bin/sh, even when the /dev directory
  52           on the rootfs is completely empty.
  53
  54 config STANDALONE
  55         bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
  56         default y
  57         help
  58           Select this option if you don't have magic firmware for drivers that
  59           need it.
  60
  61           If unsure, say Y.
  62
  63 config PREVENT_FIRMWARE_BUILD
  64         bool "Prevent firmware from being built"
  65         default y
  66         help
  67           Say yes to avoid building firmware. Firmware is usually shipped
  68           with the driver, and only when updating the firmware a rebuild
  69           should be made.
  70           If unsure say Y here.
  71
  72 config FW_LOADER
  73         tristate "Userspace firmware loading support" if EXPERT
  74         default y
  75         ---help---
  76           This option is provided for the case where no in-kernel-tree modules
  77           require userspace firmware loading support, but a module built outside
  78           the kernel tree does.
  79
  80 config FIRMWARE_IN_KERNEL
  81         bool "Include in-kernel firmware blobs in kernel binary"
  82         depends on FW_LOADER
  83         default y
  84         help
  85           The kernel source tree includes a number of firmware 'blobs'
  86           which are used by various drivers. The recommended way to
  87           use these is to run "make firmware_install" and to copy the
  88           resulting binary files created in usr/lib/firmware directory
  89           of the kernel tree to the /lib/firmware on your system so
  90           that they can be loaded by userspace helpers on request.
  91
  92           Enabling this option will build each required firmware blob
  93           into the kernel directly, where request_firmware() will find
  94           them without having to call out to userspace. This may be
  95           useful if your root file system requires a device which uses
  96           such firmware, and do not wish to use an initrd.
  97
  98           This single option controls the inclusion of firmware for
  99           every driver which uses request_firmware() and ships its
 100           firmware in the kernel source tree, to avoid a proliferation
 101           of 'Include firmware for xxx device' options.
 102
 103           Say 'N' and let firmware be loaded from userspace.
 104
 105 config EXTRA_FIRMWARE
 106         string "External firmware blobs to build into the kernel binary"
 107         depends on FW_LOADER
 108         help
 109           This option allows firmware to be built into the kernel, for the
 110           cases where the user either cannot or doesn't want to provide it from
 111           userspace at runtime (for example, when the firmware in question is
 112           required for accessing the boot device, and the user doesn't want to
 113           use an initrd).
 114
 115           This option is a string, and takes the (space-separated) names of the
 116           firmware files -- the same names which appear in MODULE_FIRMWARE()
 117           and request_firmware() in the source. These files should exist under
 118           the directory specified by the EXTRA_FIRMWARE_DIR option, which is
 119           by default the firmware/ subdirectory of the kernel source tree.
 120
 121           So, for example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin",
 122           copy the usb8388.bin file into the firmware/ directory, and build the
 123           kernel. Then any request_firmware("usb8388.bin") will be
 124           satisfied internally without needing to call out to userspace.
 125
 126           WARNING: If you include additional firmware files into your binary
 127           kernel image which are not available under the terms of the GPL,
 128           then it may be a violation of the GPL to distribute the resulting
 129           image -- since it combines both GPL and non-GPL work. You should
 130           consult a lawyer of your own before distributing such an image.
 131
 132 config EXTRA_FIRMWARE_DIR
 133         string "Firmware blobs root directory"
 134         depends on EXTRA_FIRMWARE != ""
 135         default "firmware"
 136         help
 137           This option controls the directory in which the kernel build system
 138           looks for the firmware files listed in the EXTRA_FIRMWARE option.
 139           The default is the firmware/ directory in the kernel source tree,
 140           but by changing this option you can point it elsewhere, such as
 141           the /lib/firmware/ directory or another separate directory
 142           containing firmware files.
 143
 144 config DEBUG_DRIVER
 145         bool "Driver Core verbose debug messages"
 146         depends on DEBUG_KERNEL
 147         help
 148           Say Y here if you want the Driver core to produce a bunch of
 149           debug messages to the system log. Select this if you are having a
 150           problem with the driver core and want to see more of what is
 151           going on.
 152
 153           If you are unsure about this, say N here.
 154
 155 config DEBUG_DEVRES
 156         bool "Managed device resources verbose debug messages"
 157         depends on DEBUG_KERNEL
 158         help
 159           This option enables kernel parameter devres.log. If set to
 160           non-zero, devres debug messages are printed. Select this if
 161           you are having a problem with devres or want to debug
 162           resource management for a managed device. devres.log can be
 163           switched on and off from sysfs node.
 164
 165           If you are unsure about this, Say N here.
 166
 167 config SYS_HYPERVISOR
 168         bool
 169         default n
 170
 171 endmenu