1# SPDX-License-Identifier: GPL-2.0 2menu "Generic Driver Options" 3 4config 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 19config 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 29config 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 48config 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 63config 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 72config 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 91source "drivers/base/firmware_loader/Kconfig" 92 93config WANT_DEV_COREDUMP 94 bool 95 help 96 Drivers should "select" this option if they desire to use the 97 device coredump mechanism. 98 99config 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 112config DEV_COREDUMP 113 bool 114 default y if WANT_DEV_COREDUMP 115 depends on ALLOW_DEV_COREDUMP 116 117config 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 128config 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 140config 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 152source "drivers/base/test/Kconfig" 153 154config SYS_HYPERVISOR 155 bool 156 default n 157 158config GENERIC_CPU_DEVICES 159 bool 160 default n 161 162config GENERIC_CPU_AUTOPROBE 163 bool 164 165config GENERIC_CPU_VULNERABILITIES 166 bool 167 168config SOC_BUS 169 bool 170 select GLOB 171 172source "drivers/base/regmap/Kconfig" 173 174config 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 185config 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 194config 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 202endmenu 203