drivers/base/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0
   2 menu "Generic Driver Options"
   3
   4 config UEVENT_HELPER
   5         bool "Support for uevent helper"
   6         default y
   7         help
   8           The uevent helper program is 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 UEVENT_HELPER_PATH
  20         string "path to uevent helper"
  21         depends on UEVENT_HELPER
  22         default ""
  23         help
  24           To disable user space helper program execution at by default
  25           specify an empty string here. This setting can still be altered
  26           via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
  27           later at runtime.
  28
  29 config DEVTMPFS
  30         bool "Maintain a devtmpfs filesystem to mount at /dev"
  31         help
  32           This creates a tmpfs/ramfs filesystem instance early at bootup.
  33           In this filesystem, the kernel driver core maintains device
  34           nodes with their default names and permissions for all
  35           registered devices with an assigned major/minor number.
  36           Userspace can modify the filesystem content as needed, add
  37           symlinks, and apply needed permissions.
  38           It provides a fully functional /dev directory, where usually
  39           udev runs on top, managing permissions and adding meaningful
  40           symlinks.
  41           In very limited environments, it may provide a sufficient
  42           functional /dev without any further help. It also allows simple
  43           rescue systems, and reliably handles dynamic major/minor numbers.
  44
  45           Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
  46           file system will be used instead.
  47
  48 config DEVTMPFS_MOUNT
  49         bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
  50         depends on DEVTMPFS
  51         help
  52           This will instruct the kernel to automatically mount the
  53           devtmpfs filesystem at /dev, directly after the kernel has
  54           mounted the root filesystem. The behavior can be overridden
  55           with the commandline parameter: devtmpfs.mount=0|1.
  56           This option does not affect initramfs based booting, here
  57           the devtmpfs filesystem always needs to be mounted manually
  58           after the rootfs is mounted.
  59           With this option enabled, it allows to bring up a system in
  60           rescue mode with init=/bin/sh, even when the /dev directory
  61           on the rootfs is completely empty.
  62
  63 config STANDALONE
  64         bool "Select only drivers that don't need compile-time external firmware"
  65         default y
  66         help
  67           Select this option if you don't have magic firmware for drivers that
  68           need it.
  69
  70           If unsure, say Y.
  71
  72 config PREVENT_FIRMWARE_BUILD
  73         bool "Disable drivers features which enable custom firmware building"
  74         default y
  75         help
  76           Say yes to disable driver features which enable building a custom
  77           driver firmware at kernel build time. These drivers do not use the
  78           kernel firmware API to load firmware (CONFIG_FW_LOADER), instead they
  79           use their own custom loading mechanism. The required firmware is
  80           usually shipped with the driver, building the driver firmware
  81           should only be needed if you have an updated firmware source.
  82
  83           Firmware should not be being built as part of kernel, these days
  84           you should always prevent this and say Y here. There are only two
  85           old drivers which enable building of its firmware at kernel build
  86           time:
  87
  88             o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
  89             o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
  90
  91 source "drivers/base/firmware_loader/Kconfig"
  92
  93 config WANT_DEV_COREDUMP
  94         bool
  95         help
  96           Drivers should "select" this option if they desire to use the
  97           device coredump mechanism.
  98
  99 config ALLOW_DEV_COREDUMP
 100         bool "Allow device coredump" if EXPERT
 101         default y
 102         help
 103           This option controls if the device coredump mechanism is available or
 104           not; if disabled, the mechanism will be omitted even if drivers that
 105           can use it are enabled.
 106           Say 'N' for more sensitive systems or systems that don't want
 107           to ever access the information to not have the code, nor keep any
 108           data.
 109
 110           If unsure, say Y.
 111
 112 config DEV_COREDUMP
 113         bool
 114         default y if WANT_DEV_COREDUMP
 115         depends on ALLOW_DEV_COREDUMP
 116
 117 config DEBUG_DRIVER
 118         bool "Driver Core verbose debug messages"
 119         depends on DEBUG_KERNEL
 120         help
 121           Say Y here if you want the Driver core to produce a bunch of
 122           debug messages to the system log. Select this if you are having a
 123           problem with the driver core and want to see more of what is
 124           going on.
 125
 126           If you are unsure about this, say N here.
 127
 128 config DEBUG_DEVRES
 129         bool "Managed device resources verbose debug messages"
 130         depends on DEBUG_KERNEL
 131         help
 132           This option enables kernel parameter devres.log. If set to
 133           non-zero, devres debug messages are printed. Select this if
 134           you are having a problem with devres or want to debug
 135           resource management for a managed device. devres.log can be
 136           switched on and off from sysfs node.
 137
 138           If you are unsure about this, Say N here.
 139
 140 config DEBUG_TEST_DRIVER_REMOVE
 141         bool "Test driver remove calls during probe (UNSTABLE)"
 142         depends on DEBUG_KERNEL
 143         help
 144           Say Y here if you want the Driver core to test driver remove functions
 145           by calling probe, remove, probe. This tests the remove path without
 146           having to unbind the driver or unload the driver module.
 147
 148           This option is expected to find errors and may render your system
 149           unusable. You should say N here unless you are explicitly looking to
 150           test this functionality.
 151
 152 source "drivers/base/test/Kconfig"
 153
 154 config SYS_HYPERVISOR
 155         bool
 156         default n
 157
 158 config GENERIC_CPU_DEVICES
 159         bool
 160         default n
 161
 162 config GENERIC_CPU_AUTOPROBE
 163         bool
 164
 165 config GENERIC_CPU_VULNERABILITIES
 166         bool
 167
 168 config SOC_BUS
 169         bool
 170         select GLOB
 171
 172 source "drivers/base/regmap/Kconfig"
 173
 174 config DMA_SHARED_BUFFER
 175         bool
 176         default n
 177         select ANON_INODES
 178         select IRQ_WORK
 179         help
 180           This option enables the framework for buffer-sharing between
 181           multiple drivers. A buffer is associated with a file using driver
 182           APIs extension; the file's descriptor can then be passed on to other
 183           driver.
 184
 185 config DMA_FENCE_TRACE
 186         bool "Enable verbose DMA_FENCE_TRACE messages"
 187         depends on DMA_SHARED_BUFFER
 188         help
 189           Enable the DMA_FENCE_TRACE printks. This will add extra
 190           spam to the console log, but will make it easier to diagnose
 191           lockup related problems for dma-buffers shared across multiple
 192           devices.
 193
 194 config GENERIC_ARCH_TOPOLOGY
 195         bool
 196         help
 197           Enable support for architectures common topology code: e.g., parsing
 198           CPU capacity information from DT, usage of such information for
 199           appropriate scaling, sysfs interface for changing capacity values at
 200           runtime.
 201
 202 endmenu