1# SPDX-License-Identifier: GPL-2.0 2menu "Generic Driver Options" 3 4config AUXILIARY_BUS 5 bool 6 7config 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 21config 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 31config 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 50config 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 65config 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 74config 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 93source "drivers/base/firmware_loader/Kconfig" 94 95config WANT_DEV_COREDUMP 96 bool 97 help 98 Drivers should "select" this option if they desire to use the 99 device coredump mechanism. 100 101config 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 114config DEV_COREDUMP 115 bool 116 default y if WANT_DEV_COREDUMP 117 depends on ALLOW_DEV_COREDUMP 118 119config 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 130config 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 142config 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 154config 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 159config HMEM_REPORTING 160 bool 161 default n 162 depends on NUMA 163 help 164 Enable reporting for heterogenous memory access attributes under 165 their non-uniform memory nodes. 166 167source "drivers/base/test/Kconfig" 168 169config SYS_HYPERVISOR 170 bool 171 default n 172 173config GENERIC_CPU_DEVICES 174 bool 175 default n 176 177config GENERIC_CPU_AUTOPROBE 178 bool 179 180config GENERIC_CPU_VULNERABILITIES 181 bool 182 183config SOC_BUS 184 bool 185 select GLOB 186 187source "drivers/base/regmap/Kconfig" 188 189config 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 199config 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 208config 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 216endmenu 217