| 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 DEVTMPFS_SAFE |
| 66 | bool "Use nosuid,noexec mount options on devtmpfs" |
| 67 | depends on DEVTMPFS |
| 68 | help |
| 69 | This instructs the kernel to include the MS_NOEXEC and MS_NOSUID mount |
| 70 | flags when mounting devtmpfs. |
| 71 | |
| 72 | Notice: If enabled, things like /dev/mem cannot be mmapped |
| 73 | with the PROT_EXEC flag. This can break, for example, non-KMS |
| 74 | video drivers. |
| 75 | |
| 76 | config DRIVER_DEFERRED_PROBE_TIMEOUT |
| 77 | int "Default value for deferred_probe_timeout" |
| 78 | default 0 if !MODULES |
| 79 | default 10 if MODULES |
| 80 | help |
| 81 | Set the default value for the deferred_probe_timeout kernel parameter. |
| 82 | See Documentation/admin-guide/kernel-parameters.txt for a description |
| 83 | of the deferred_probe_timeout kernel parameter. |
| 84 | |
| 85 | config STANDALONE |
| 86 | bool "Select only drivers that don't need compile-time external firmware" |
| 87 | default y |
| 88 | help |
| 89 | Select this option if you don't have magic firmware for drivers that |
| 90 | need it. |
| 91 | |
| 92 | If unsure, say Y. |
| 93 | |
| 94 | config PREVENT_FIRMWARE_BUILD |
| 95 | bool "Disable drivers features which enable custom firmware building" |
| 96 | default y |
| 97 | help |
| 98 | Say yes to disable driver features which enable building a custom |
| 99 | driver firmware at kernel build time. These drivers do not use the |
| 100 | kernel firmware API to load firmware (CONFIG_FW_LOADER), instead they |
| 101 | use their own custom loading mechanism. The required firmware is |
| 102 | usually shipped with the driver, building the driver firmware |
| 103 | should only be needed if you have an updated firmware source. |
| 104 | |
| 105 | Firmware should not be being built as part of kernel, these days |
| 106 | you should always prevent this and say Y here. There are only two |
| 107 | old drivers which enable building of its firmware at kernel build |
| 108 | time: |
| 109 | |
| 110 | o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE |
| 111 | o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE |
| 112 | |
| 113 | source "drivers/base/firmware_loader/Kconfig" |
| 114 | |
| 115 | config WANT_DEV_COREDUMP |
| 116 | bool |
| 117 | help |
| 118 | Drivers should "select" this option if they desire to use the |
| 119 | device coredump mechanism. |
| 120 | |
| 121 | config ALLOW_DEV_COREDUMP |
| 122 | bool "Allow device coredump" if EXPERT |
| 123 | default y |
| 124 | help |
| 125 | This option controls if the device coredump mechanism is available or |
| 126 | not; if disabled, the mechanism will be omitted even if drivers that |
| 127 | can use it are enabled. |
| 128 | Say 'N' for more sensitive systems or systems that don't want |
| 129 | to ever access the information to not have the code, nor keep any |
| 130 | data. |
| 131 | |
| 132 | If unsure, say Y. |
| 133 | |
| 134 | config DEV_COREDUMP |
| 135 | bool |
| 136 | default y if WANT_DEV_COREDUMP |
| 137 | depends on ALLOW_DEV_COREDUMP |
| 138 | |
| 139 | config DEBUG_DRIVER |
| 140 | bool "Driver Core verbose debug messages" |
| 141 | depends on DEBUG_KERNEL |
| 142 | help |
| 143 | Say Y here if you want the Driver core to produce a bunch of |
| 144 | debug messages to the system log. Select this if you are having a |
| 145 | problem with the driver core and want to see more of what is |
| 146 | going on. |
| 147 | |
| 148 | If you are unsure about this, say N here. |
| 149 | |
| 150 | config DEBUG_DEVRES |
| 151 | bool "Managed device resources verbose debug messages" |
| 152 | depends on DEBUG_KERNEL |
| 153 | help |
| 154 | This option enables kernel parameter devres.log. If set to |
| 155 | non-zero, devres debug messages are printed. Select this if |
| 156 | you are having a problem with devres or want to debug |
| 157 | resource management for a managed device. devres.log can be |
| 158 | switched on and off from sysfs node. |
| 159 | |
| 160 | If you are unsure about this, Say N here. |
| 161 | |
| 162 | config DEBUG_TEST_DRIVER_REMOVE |
| 163 | bool "Test driver remove calls during probe (UNSTABLE)" |
| 164 | depends on DEBUG_KERNEL |
| 165 | help |
| 166 | Say Y here if you want the Driver core to test driver remove functions |
| 167 | by calling probe, remove, probe. This tests the remove path without |
| 168 | having to unbind the driver or unload the driver module. |
| 169 | |
| 170 | This option is expected to find errors and may render your system |
| 171 | unusable. You should say N here unless you are explicitly looking to |
| 172 | test this functionality. |
| 173 | |
| 174 | config PM_QOS_KUNIT_TEST |
| 175 | bool "KUnit Test for PM QoS features" if !KUNIT_ALL_TESTS |
| 176 | depends on KUNIT=y |
| 177 | default KUNIT_ALL_TESTS |
| 178 | |
| 179 | config PM_RUNTIME_KUNIT_TEST |
| 180 | tristate "KUnit Tests for runtime PM" if !KUNIT_ALL_TESTS |
| 181 | depends on KUNIT |
| 182 | depends on PM |
| 183 | default KUNIT_ALL_TESTS |
| 184 | |
| 185 | config HMEM_REPORTING |
| 186 | bool |
| 187 | default n |
| 188 | depends on NUMA |
| 189 | help |
| 190 | Enable reporting for heterogeneous memory access attributes under |
| 191 | their non-uniform memory nodes. |
| 192 | |
| 193 | source "drivers/base/test/Kconfig" |
| 194 | |
| 195 | config SYS_HYPERVISOR |
| 196 | bool |
| 197 | default n |
| 198 | |
| 199 | config GENERIC_CPU_DEVICES |
| 200 | bool |
| 201 | default n |
| 202 | |
| 203 | config GENERIC_CPU_AUTOPROBE |
| 204 | bool |
| 205 | |
| 206 | config GENERIC_CPU_VULNERABILITIES |
| 207 | bool |
| 208 | |
| 209 | config SOC_BUS |
| 210 | bool |
| 211 | select GLOB |
| 212 | |
| 213 | source "drivers/base/regmap/Kconfig" |
| 214 | |
| 215 | config DMA_SHARED_BUFFER |
| 216 | bool |
| 217 | default n |
| 218 | select IRQ_WORK |
| 219 | help |
| 220 | This option enables the framework for buffer-sharing between |
| 221 | multiple drivers. A buffer is associated with a file using driver |
| 222 | APIs extension; the file's descriptor can then be passed on to other |
| 223 | driver. |
| 224 | |
| 225 | config GENERIC_ARCH_TOPOLOGY |
| 226 | bool |
| 227 | help |
| 228 | Enable support for architectures common topology code: e.g., parsing |
| 229 | CPU capacity information from DT, usage of such information for |
| 230 | appropriate scaling, sysfs interface for reading capacity values at |
| 231 | runtime. |
| 232 | |
| 233 | config FW_DEVLINK_SYNC_STATE_TIMEOUT |
| 234 | bool "sync_state() behavior defaults to timeout instead of strict" |
| 235 | help |
| 236 | This is build time equivalent of adding kernel command line parameter |
| 237 | "fw_devlink.sync_state=timeout". Give up waiting on consumers and |
| 238 | call sync_state() on any devices that haven't yet received their |
| 239 | sync_state() calls after deferred_probe_timeout has expired or by |
| 240 | late_initcall() if !CONFIG_MODULES. You should almost always want to |
| 241 | select N here unless you have already successfully tested with the |
| 242 | command line option on every system/board your kernel is expected to |
| 243 | work on. |
| 244 | |
| 245 | endmenu |