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 && SHMEM && TMPFS
  22         help
  23           This creates a tmpfs 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 config DEVTMPFS_MOUNT
  37         bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
  38         depends on DEVTMPFS
  39         help
  40           This will instruct the kernel to automatically mount the
  41           devtmpfs filesystem at /dev, directly after the kernel has
  42           mounted the root filesystem. The behavior can be overridden
  43           with the commandline parameter: devtmpfs.mount=0|1.
  44           This option does not affect initramfs based booting, here
  45           the devtmpfs filesystem always needs to be mounted manually
  46           after the roots is mounted.
  47           With this option enabled, it allows to bring up a system in
  48           rescue mode with init=/bin/sh, even when the /dev directory
  49           on the rootfs is completely empty.
  50
  51 config STANDALONE
  52         bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
  53         default y
  54         help
  55           Select this option if you don't have magic firmware for drivers that
  56           need it.
  57
  58           If unsure, say Y.
  59
  60 config PREVENT_FIRMWARE_BUILD
  61         bool "Prevent firmware from being built"
  62         default y
  63         help
  64           Say yes to avoid building firmware. Firmware is usually shipped
  65           with the driver, and only when updating the firmware a rebuild
  66           should be made.
  67           If unsure say Y here.
  68
  69 config FW_LOADER
  70         tristate "Userspace firmware loading support" if EMBEDDED
  71         depends on HOTPLUG
  72         default y
  73         ---help---
  74           This option is provided for the case where no in-kernel-tree modules
  75           require userspace firmware loading support, but a module built outside
  76           the kernel tree does.
  77
  78 config FIRMWARE_IN_KERNEL
  79         bool "Include in-kernel firmware blobs in kernel binary"
  80         depends on FW_LOADER
  81         default y
  82         help
  83           The kernel source tree includes a number of firmware 'blobs'
  84           which are used by various drivers. The recommended way to
  85           use these is to run "make firmware_install" and to copy the
  86           resulting binary files created in usr/lib/firmware directory
  87           of the kernel tree to the /lib/firmware on your system so
  88           that they can be loaded by userspace helpers on request.
  89
  90           Enabling this option will build each required firmware blob
  91           into the kernel directly, where request_firmware() will find
  92           them without having to call out to userspace. This may be
  93           useful if your root file system requires a device which uses
  94           such firmware, and do not wish to use an initrd.
  95
  96           This single option controls the inclusion of firmware for
  97           every driver which uses request_firmware() and ships its
  98           firmware in the kernel source tree, to avoid a proliferation
  99           of 'Include firmware for xxx device' options.
 100
 101           Say 'N' and let firmware be loaded from userspace.
 102
 103 config EXTRA_FIRMWARE
 104         string "External firmware blobs to build into the kernel binary"
 105         depends on FW_LOADER
 106         help
 107           This option allows firmware to be built into the kernel, for the
 108           cases where the user either cannot or doesn't want to provide it from
 109           userspace at runtime (for example, when the firmware in question is
 110           required for accessing the boot device, and the user doesn't want to
 111           use an initrd).
 112
 113           This option is a string, and takes the (space-separated) names of the
 114           firmware files -- the same names which appear in MODULE_FIRMWARE()
 115           and request_firmware() in the source. These files should exist under
 116           the directory specified by the EXTRA_FIRMWARE_DIR option, which is
 117           by default the firmware/ subdirectory of the kernel source tree.
 118
 119           So, for example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin",
 120           copy the usb8388.bin file into the firmware/ directory, and build the
 121           kernel. Then any request_firmware("usb8388.bin") will be
 122           satisfied internally without needing to call out to userspace.
 123
 124           WARNING: If you include additional firmware files into your binary
 125           kernel image which are not available under the terms of the GPL,
 126           then it may be a violation of the GPL to distribute the resulting
 127           image -- since it combines both GPL and non-GPL work. You should
 128           consult a lawyer of your own before distributing such an image.
 129
 130 config EXTRA_FIRMWARE_DIR
 131         string "Firmware blobs root directory"
 132         depends on EXTRA_FIRMWARE != ""
 133         default "firmware"
 134         help
 135           This option controls the directory in which the kernel build system
 136           looks for the firmware files listed in the EXTRA_FIRMWARE option.
 137           The default is the firmware/ directory in the kernel source tree,
 138           but by changing this option you can point it elsewhere, such as
 139           the /lib/firmware/ directory or another separate directory
 140           containing firmware files.
 141
 142 config DEBUG_DRIVER
 143         bool "Driver Core verbose debug messages"
 144         depends on DEBUG_KERNEL
 145         help
 146           Say Y here if you want the Driver core to produce a bunch of
 147           debug messages to the system log. Select this if you are having a
 148           problem with the driver core and want to see more of what is
 149           going on.
 150
 151           If you are unsure about this, say N here.
 152
 153 config DEBUG_DEVRES
 154         bool "Managed device resources verbose debug messages"
 155         depends on DEBUG_KERNEL
 156         help
 157           This option enables kernel parameter devres.log. If set to
 158           non-zero, devres debug messages are printed. Select this if
 159           you are having a problem with devres or want to debug
 160           resource management for a managed device. devres.log can be
 161           switched on and off from sysfs node.
 162
 163           If you are unsure about this, Say N here.
 164
 165 config SYS_HYPERVISOR
 166         bool
 167         default n
 168
 169 endmenu