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1# SPDX-License-Identifier: GPL-2.0
2menu "Generic Driver Options"
3
4config UEVENT_HELPER
5 bool "Support for uevent helper"
6 help
7 The uevent helper program is forked by the kernel for
8 every uevent.
9 Before the switch to the netlink-based uevent source, this was
10 used to hook hotplug scripts into kernel device events. It
11 usually pointed to a shell script at /sbin/hotplug.
12 This should not be used today, because usual systems create
13 many events at bootup or device discovery in a very short time
14 frame. One forked process per event can create so many processes
15 that it creates a high system load, or on smaller systems
16 it is known to create out-of-memory situations during bootup.
17
18config UEVENT_HELPER_PATH
19 string "path to uevent helper"
20 depends on UEVENT_HELPER
21 default ""
22 help
23 To disable user space helper program execution at by default
24 specify an empty string here. This setting can still be altered
25 via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
26 later at runtime.
27
28config DEVTMPFS
29 bool "Maintain a devtmpfs filesystem to mount at /dev"
30 help
31 This creates a tmpfs/ramfs filesystem instance early at bootup.
32 In this filesystem, the kernel driver core maintains device
33 nodes with their default names and permissions for all
34 registered devices with an assigned major/minor number.
35 Userspace can modify the filesystem content as needed, add
36 symlinks, and apply needed permissions.
37 It provides a fully functional /dev directory, where usually
38 udev runs on top, managing permissions and adding meaningful
39 symlinks.
40 In very limited environments, it may provide a sufficient
41 functional /dev without any further help. It also allows simple
42 rescue systems, and reliably handles dynamic major/minor numbers.
43
44 Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
45 file system will be used instead.
46
47config DEVTMPFS_MOUNT
48 bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
49 depends on DEVTMPFS
50 help
51 This will instruct the kernel to automatically mount the
52 devtmpfs filesystem at /dev, directly after the kernel has
53 mounted the root filesystem. The behavior can be overridden
54 with the commandline parameter: devtmpfs.mount=0|1.
55 This option does not affect initramfs based booting, here
56 the devtmpfs filesystem always needs to be mounted manually
57 after the rootfs is mounted.
58 With this option enabled, it allows to bring up a system in
59 rescue mode with init=/bin/sh, even when the /dev directory
60 on the rootfs is completely empty.
61
62config STANDALONE
63 bool "Select only drivers that don't need compile-time external firmware"
64 default y
65 help
66 Select this option if you don't have magic firmware for drivers that
67 need it.
68
69 If unsure, say Y.
70
71config PREVENT_FIRMWARE_BUILD
72 bool "Disable drivers features which enable custom firmware building"
73 default y
74 help
75 Say yes to disable driver features which enable building a custom
76 driver firmware at kernel build time. These drivers do not use the
77 kernel firmware API to load firmware (CONFIG_FW_LOADER), instead they
78 use their own custom loading mechanism. The required firmware is
79 usually shipped with the driver, building the driver firmware
80 should only be needed if you have an updated firmware source.
81
82 Firmware should not be being built as part of kernel, these days
83 you should always prevent this and say Y here. There are only two
84 old drivers which enable building of its firmware at kernel build
85 time:
86
87 o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
88 o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
89
90source "drivers/base/firmware_loader/Kconfig"
91
92config WANT_DEV_COREDUMP
93 bool
94 help
95 Drivers should "select" this option if they desire to use the
96 device coredump mechanism.
97
98config ALLOW_DEV_COREDUMP
99 bool "Allow device coredump" if EXPERT
100 default y
101 help
102 This option controls if the device coredump mechanism is available or
103 not; if disabled, the mechanism will be omitted even if drivers that
104 can use it are enabled.
105 Say 'N' for more sensitive systems or systems that don't want
106 to ever access the information to not have the code, nor keep any
107 data.
108
109 If unsure, say Y.
110
111config DEV_COREDUMP
112 bool
113 default y if WANT_DEV_COREDUMP
114 depends on ALLOW_DEV_COREDUMP
115
116config DEBUG_DRIVER
117 bool "Driver Core verbose debug messages"
118 depends on DEBUG_KERNEL
119 help
120 Say Y here if you want the Driver core to produce a bunch of
121 debug messages to the system log. Select this if you are having a
122 problem with the driver core and want to see more of what is
123 going on.
124
125 If you are unsure about this, say N here.
126
127config DEBUG_DEVRES
128 bool "Managed device resources verbose debug messages"
129 depends on DEBUG_KERNEL
130 help
131 This option enables kernel parameter devres.log. If set to
132 non-zero, devres debug messages are printed. Select this if
133 you are having a problem with devres or want to debug
134 resource management for a managed device. devres.log can be
135 switched on and off from sysfs node.
136
137 If you are unsure about this, Say N here.
138
139config DEBUG_TEST_DRIVER_REMOVE
140 bool "Test driver remove calls during probe (UNSTABLE)"
141 depends on DEBUG_KERNEL
142 help
143 Say Y here if you want the Driver core to test driver remove functions
144 by calling probe, remove, probe. This tests the remove path without
145 having to unbind the driver or unload the driver module.
146
147 This option is expected to find errors and may render your system
148 unusable. You should say N here unless you are explicitly looking to
149 test this functionality.
150
151config PM_QOS_KUNIT_TEST
152 bool "KUnit Test for PM QoS features" if !KUNIT_ALL_TESTS
153 depends on KUNIT=y
154 default KUNIT_ALL_TESTS
155
156config HMEM_REPORTING
157 bool
158 default n
159 depends on NUMA
160 help
161 Enable reporting for heterogenous memory access attributes under
162 their non-uniform memory nodes.
163
164source "drivers/base/test/Kconfig"
165
166config SYS_HYPERVISOR
167 bool
168 default n
169
170config GENERIC_CPU_DEVICES
171 bool
172 default n
173
174config GENERIC_CPU_AUTOPROBE
175 bool
176
177config GENERIC_CPU_VULNERABILITIES
178 bool
179
180config SOC_BUS
181 bool
182 select GLOB
183
184source "drivers/base/regmap/Kconfig"
185
186config DMA_SHARED_BUFFER
187 bool
188 default n
189 select IRQ_WORK
190 help
191 This option enables the framework for buffer-sharing between
192 multiple drivers. A buffer is associated with a file using driver
193 APIs extension; the file's descriptor can then be passed on to other
194 driver.
195
196config DMA_FENCE_TRACE
197 bool "Enable verbose DMA_FENCE_TRACE messages"
198 depends on DMA_SHARED_BUFFER
199 help
200 Enable the DMA_FENCE_TRACE printks. This will add extra
201 spam to the console log, but will make it easier to diagnose
202 lockup related problems for dma-buffers shared across multiple
203 devices.
204
205config GENERIC_ARCH_TOPOLOGY
206 bool
207 help
208 Enable support for architectures common topology code: e.g., parsing
209 CPU capacity information from DT, usage of such information for
210 appropriate scaling, sysfs interface for reading capacity values at
211 runtime.
212
213endmenu
1menu "Generic Driver Options"
2
3config UEVENT_HELPER_PATH
4 string "path to uevent helper"
5 depends on HOTPLUG
6 default ""
7 help
8 Path to uevent helper program 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 To disable user space helper program execution at early boot
20 time specify an empty string here. This setting can be altered
21 via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
22 later at runtime.
23
24config DEVTMPFS
25 bool "Maintain a devtmpfs filesystem to mount at /dev"
26 depends on HOTPLUG
27 help
28 This creates a tmpfs/ramfs filesystem instance early at bootup.
29 In this filesystem, the kernel driver core maintains device
30 nodes with their default names and permissions for all
31 registered devices with an assigned major/minor number.
32 Userspace can modify the filesystem content as needed, add
33 symlinks, and apply needed permissions.
34 It provides a fully functional /dev directory, where usually
35 udev runs on top, managing permissions and adding meaningful
36 symlinks.
37 In very limited environments, it may provide a sufficient
38 functional /dev without any further help. It also allows simple
39 rescue systems, and reliably handles dynamic major/minor numbers.
40
41 Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
42 file system will be used instead.
43
44config DEVTMPFS_MOUNT
45 bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
46 depends on DEVTMPFS
47 help
48 This will instruct the kernel to automatically mount the
49 devtmpfs filesystem at /dev, directly after the kernel has
50 mounted the root filesystem. The behavior can be overridden
51 with the commandline parameter: devtmpfs.mount=0|1.
52 This option does not affect initramfs based booting, here
53 the devtmpfs filesystem always needs to be mounted manually
54 after the roots is mounted.
55 With this option enabled, it allows to bring up a system in
56 rescue mode with init=/bin/sh, even when the /dev directory
57 on the rootfs is completely empty.
58
59config STANDALONE
60 bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
61 default y
62 help
63 Select this option if you don't have magic firmware for drivers that
64 need it.
65
66 If unsure, say Y.
67
68config PREVENT_FIRMWARE_BUILD
69 bool "Prevent firmware from being built"
70 default y
71 help
72 Say yes to avoid building firmware. Firmware is usually shipped
73 with the driver and only when updating the firmware should a
74 rebuild be made.
75 If unsure, say Y here.
76
77config FW_LOADER
78 tristate "Userspace firmware loading support" if EXPERT
79 default y
80 ---help---
81 This option is provided for the case where none of the in-tree modules
82 require userspace firmware loading support, but a module built
83 out-of-tree does.
84
85config FIRMWARE_IN_KERNEL
86 bool "Include in-kernel firmware blobs in kernel binary"
87 depends on FW_LOADER
88 default y
89 help
90 The kernel source tree includes a number of firmware 'blobs'
91 that are used by various drivers. The recommended way to
92 use these is to run "make firmware_install", which, after
93 converting ihex files to binary, copies all of the needed
94 binary files in firmware/ to /lib/firmware/ on your system so
95 that they can be loaded by userspace helpers on request.
96
97 Enabling this option will build each required firmware blob
98 into the kernel directly, where request_firmware() will find
99 them without having to call out to userspace. This may be
100 useful if your root file system requires a device that uses
101 such firmware and do not wish to use an initrd.
102
103 This single option controls the inclusion of firmware for
104 every driver that uses request_firmware() and ships its
105 firmware in the kernel source tree, which avoids a
106 proliferation of 'Include firmware for xxx device' options.
107
108 Say 'N' and let firmware be loaded from userspace.
109
110config EXTRA_FIRMWARE
111 string "External firmware blobs to build into the kernel binary"
112 depends on FW_LOADER
113 help
114 This option allows firmware to be built into the kernel for the case
115 where the user either cannot or doesn't want to provide it from
116 userspace at runtime (for example, when the firmware in question is
117 required for accessing the boot device, and the user doesn't want to
118 use an initrd).
119
120 This option is a string and takes the (space-separated) names of the
121 firmware files -- the same names that appear in MODULE_FIRMWARE()
122 and request_firmware() in the source. These files should exist under
123 the directory specified by the EXTRA_FIRMWARE_DIR option, which is
124 by default the firmware subdirectory of the kernel source tree.
125
126 For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
127 the usb8388.bin file into the firmware directory, and build the kernel.
128 Then any request_firmware("usb8388.bin") will be satisfied internally
129 without needing to call out to userspace.
130
131 WARNING: If you include additional firmware files into your binary
132 kernel image that are not available under the terms of the GPL,
133 then it may be a violation of the GPL to distribute the resulting
134 image since it combines both GPL and non-GPL work. You should
135 consult a lawyer of your own before distributing such an image.
136
137config EXTRA_FIRMWARE_DIR
138 string "Firmware blobs root directory"
139 depends on EXTRA_FIRMWARE != ""
140 default "firmware"
141 help
142 This option controls the directory in which the kernel build system
143 looks for the firmware files listed in the EXTRA_FIRMWARE option.
144 The default is firmware/ in the kernel source tree, but by changing
145 this option you can point it elsewhere, such as /lib/firmware/ or
146 some other directory containing the firmware files.
147
148config DEBUG_DRIVER
149 bool "Driver Core verbose debug messages"
150 depends on DEBUG_KERNEL
151 help
152 Say Y here if you want the Driver core to produce a bunch of
153 debug messages to the system log. Select this if you are having a
154 problem with the driver core and want to see more of what is
155 going on.
156
157 If you are unsure about this, say N here.
158
159config DEBUG_DEVRES
160 bool "Managed device resources verbose debug messages"
161 depends on DEBUG_KERNEL
162 help
163 This option enables kernel parameter devres.log. If set to
164 non-zero, devres debug messages are printed. Select this if
165 you are having a problem with devres or want to debug
166 resource management for a managed device. devres.log can be
167 switched on and off from sysfs node.
168
169 If you are unsure about this, Say N here.
170
171config SYS_HYPERVISOR
172 bool
173 default n
174
175source "drivers/base/regmap/Kconfig"
176
177endmenu