drivers/base/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0
   2 menu "Generic Driver Options"
   3
   4 config AUXILIARY_BUS
   5         bool
   6
   7 config UEVENT_HELPER
   8         bool "Support for uevent helper"
   9         help
  10           The uevent helper program is forked by the kernel for
  11           every uevent.
  12           Before the switch to the netlink-based uevent source, this was
  13           used to hook hotplug scripts into kernel device events. It
  14           usually pointed to a shell script at /sbin/hotplug.
  15           This should not be used today, because usual systems create
  16           many events at bootup or device discovery in a very short time
  17           frame. One forked process per event can create so many processes
  18           that it creates a high system load, or on smaller systems
  19           it is known to create out-of-memory situations during bootup.
  20
  21 config UEVENT_HELPER_PATH
  22         string "path to uevent helper"
  23         depends on UEVENT_HELPER
  24         default ""
  25         help
  26           To disable user space helper program execution at by default
  27           specify an empty string here. This setting can still be altered
  28           via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
  29           later at runtime.
  30
  31 config DEVTMPFS
  32         bool "Maintain a devtmpfs filesystem to mount at /dev"
  33         help
  34           This creates a tmpfs/ramfs filesystem instance early at bootup.
  35           In this filesystem, the kernel driver core maintains device
  36           nodes with their default names and permissions for all
  37           registered devices with an assigned major/minor number.
  38           Userspace can modify the filesystem content as needed, add
  39           symlinks, and apply needed permissions.
  40           It provides a fully functional /dev directory, where usually
  41           udev runs on top, managing permissions and adding meaningful
  42           symlinks.
  43           In very limited environments, it may provide a sufficient
  44           functional /dev without any further help. It also allows simple
  45           rescue systems, and reliably handles dynamic major/minor numbers.
  46
  47           Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
  48           file system will be used instead.
  49
  50 config DEVTMPFS_MOUNT
  51         bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
  52         depends on DEVTMPFS
  53         help
  54           This will instruct the kernel to automatically mount the
  55           devtmpfs filesystem at /dev, directly after the kernel has
  56           mounted the root filesystem. The behavior can be overridden
  57           with the commandline parameter: devtmpfs.mount=0|1.
  58           This option does not affect initramfs based booting, here
  59           the devtmpfs filesystem always needs to be mounted manually
  60           after the rootfs is mounted.
  61           With this option enabled, it allows to bring up a system in
  62           rescue mode with init=/bin/sh, even when the /dev directory
  63           on the rootfs is completely empty.
  64
  65 config STANDALONE
  66         bool "Select only drivers that don't need compile-time external firmware"
  67         default y
  68         help
  69           Select this option if you don't have magic firmware for drivers that
  70           need it.
  71
  72           If unsure, say Y.
  73
  74 config PREVENT_FIRMWARE_BUILD
  75         bool "Disable drivers features which enable custom firmware building"
  76         default y
  77         help
  78           Say yes to disable driver features which enable building a custom
  79           driver firmware at kernel build time. These drivers do not use the
  80           kernel firmware API to load firmware (CONFIG_FW_LOADER), instead they
  81           use their own custom loading mechanism. The required firmware is
  82           usually shipped with the driver, building the driver firmware
  83           should only be needed if you have an updated firmware source.
  84
  85           Firmware should not be being built as part of kernel, these days
  86           you should always prevent this and say Y here. There are only two
  87           old drivers which enable building of its firmware at kernel build
  88           time:
  89
  90             o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
  91             o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
  92
  93 source "drivers/base/firmware_loader/Kconfig"
  94
  95 config WANT_DEV_COREDUMP
  96         bool
  97         help
  98           Drivers should "select" this option if they desire to use the
  99           device coredump mechanism.
 100
 101 config ALLOW_DEV_COREDUMP
 102         bool "Allow device coredump" if EXPERT
 103         default y
 104         help
 105           This option controls if the device coredump mechanism is available or
 106           not; if disabled, the mechanism will be omitted even if drivers that
 107           can use it are enabled.
 108           Say 'N' for more sensitive systems or systems that don't want
 109           to ever access the information to not have the code, nor keep any
 110           data.
 111
 112           If unsure, say Y.
 113
 114 config DEV_COREDUMP
 115         bool
 116         default y if WANT_DEV_COREDUMP
 117         depends on ALLOW_DEV_COREDUMP
 118
 119 config DEBUG_DRIVER
 120         bool "Driver Core verbose debug messages"
 121         depends on DEBUG_KERNEL
 122         help
 123           Say Y here if you want the Driver core to produce a bunch of
 124           debug messages to the system log. Select this if you are having a
 125           problem with the driver core and want to see more of what is
 126           going on.
 127
 128           If you are unsure about this, say N here.
 129
 130 config DEBUG_DEVRES
 131         bool "Managed device resources verbose debug messages"
 132         depends on DEBUG_KERNEL
 133         help
 134           This option enables kernel parameter devres.log. If set to
 135           non-zero, devres debug messages are printed. Select this if
 136           you are having a problem with devres or want to debug
 137           resource management for a managed device. devres.log can be
 138           switched on and off from sysfs node.
 139
 140           If you are unsure about this, Say N here.
 141
 142 config DEBUG_TEST_DRIVER_REMOVE
 143         bool "Test driver remove calls during probe (UNSTABLE)"
 144         depends on DEBUG_KERNEL
 145         help
 146           Say Y here if you want the Driver core to test driver remove functions
 147           by calling probe, remove, probe. This tests the remove path without
 148           having to unbind the driver or unload the driver module.
 149
 150           This option is expected to find errors and may render your system
 151           unusable. You should say N here unless you are explicitly looking to
 152           test this functionality.
 153
 154 config PM_QOS_KUNIT_TEST
 155         bool "KUnit Test for PM QoS features" if !KUNIT_ALL_TESTS
 156         depends on KUNIT=y
 157         default KUNIT_ALL_TESTS
 158
 159 config HMEM_REPORTING
 160         bool
 161         default n
 162         depends on NUMA
 163         help
 164           Enable reporting for heterogeneous memory access attributes under
 165           their non-uniform memory nodes.
 166
 167 source "drivers/base/test/Kconfig"
 168
 169 config SYS_HYPERVISOR
 170         bool
 171         default n
 172
 173 config GENERIC_CPU_DEVICES
 174         bool
 175         default n
 176
 177 config GENERIC_CPU_AUTOPROBE
 178         bool
 179
 180 config GENERIC_CPU_VULNERABILITIES
 181         bool
 182
 183 config SOC_BUS
 184         bool
 185         select GLOB
 186
 187 source "drivers/base/regmap/Kconfig"
 188
 189 config DMA_SHARED_BUFFER
 190         bool
 191         default n
 192         select IRQ_WORK
 193         help
 194           This option enables the framework for buffer-sharing between
 195           multiple drivers. A buffer is associated with a file using driver
 196           APIs extension; the file's descriptor can then be passed on to other
 197           driver.
 198
 199 config DMA_FENCE_TRACE
 200         bool "Enable verbose DMA_FENCE_TRACE messages"
 201         depends on DMA_SHARED_BUFFER
 202         help
 203           Enable the DMA_FENCE_TRACE printks. This will add extra
 204           spam to the console log, but will make it easier to diagnose
 205           lockup related problems for dma-buffers shared across multiple
 206           devices.
 207
 208 config GENERIC_ARCH_TOPOLOGY
 209         bool
 210         help
 211           Enable support for architectures common topology code: e.g., parsing
 212           CPU capacity information from DT, usage of such information for
 213           appropriate scaling, sysfs interface for reading capacity values at
 214           runtime.
 215
 216 config GENERIC_ARCH_NUMA
 217         bool
 218         help
 219           Enable support for generic NUMA implementation. Currently, RISC-V
 220           and ARM64 use it.
 221
 222 endmenu