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Diffstat (limited to 'kernel/drivers/base/Kconfig')
| -rw-r--r-- | kernel/drivers/base/Kconfig | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/kernel/drivers/base/Kconfig b/kernel/drivers/base/Kconfig new file mode 100644 index 000000000..98504ec99 --- /dev/null +++ b/kernel/drivers/base/Kconfig @@ -0,0 +1,327 @@ +menu "Generic Driver Options" + +config UEVENT_HELPER + bool "Support for uevent helper" + default y + help + The uevent helper program is forked by the kernel for + every uevent. + Before the switch to the netlink-based uevent source, this was + used to hook hotplug scripts into kernel device events. It + usually pointed to a shell script at /sbin/hotplug. + This should not be used today, because usual systems create + many events at bootup or device discovery in a very short time + frame. One forked process per event can create so many processes + that it creates a high system load, or on smaller systems + it is known to create out-of-memory situations during bootup. + +config UEVENT_HELPER_PATH + string "path to uevent helper" + depends on UEVENT_HELPER + default "" + help + To disable user space helper program execution at by default + specify an empty string here. This setting can still be altered + via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper + later at runtime. + +config DEVTMPFS + bool "Maintain a devtmpfs filesystem to mount at /dev" + help + This creates a tmpfs/ramfs filesystem instance early at bootup. + In this filesystem, the kernel driver core maintains device + nodes with their default names and permissions for all + registered devices with an assigned major/minor number. + Userspace can modify the filesystem content as needed, add + symlinks, and apply needed permissions. + It provides a fully functional /dev directory, where usually + udev runs on top, managing permissions and adding meaningful + symlinks. + In very limited environments, it may provide a sufficient + functional /dev without any further help. It also allows simple + rescue systems, and reliably handles dynamic major/minor numbers. + + Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs + file system will be used instead. + +config DEVTMPFS_MOUNT + bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs" + depends on DEVTMPFS + help + This will instruct the kernel to automatically mount the + devtmpfs filesystem at /dev, directly after the kernel has + mounted the root filesystem. The behavior can be overridden + with the commandline parameter: devtmpfs.mount=0|1. + This option does not affect initramfs based booting, here + the devtmpfs filesystem always needs to be mounted manually + after the rootfs is mounted. + With this option enabled, it allows to bring up a system in + rescue mode with init=/bin/sh, even when the /dev directory + on the rootfs is completely empty. + +config STANDALONE + bool "Select only drivers that don't need compile-time external firmware" + default y + help + Select this option if you don't have magic firmware for drivers that + need it. + + If unsure, say Y. + +config PREVENT_FIRMWARE_BUILD + bool "Prevent firmware from being built" + default y + help + Say yes to avoid building firmware. Firmware is usually shipped + with the driver and only when updating the firmware should a + rebuild be made. + If unsure, say Y here. + +config FW_LOADER + tristate "Userspace firmware loading support" if EXPERT + default y + ---help--- + This option is provided for the case where none of the in-tree modules + require userspace firmware loading support, but a module built + out-of-tree does. + +config FIRMWARE_IN_KERNEL + bool "Include in-kernel firmware blobs in kernel binary" + depends on FW_LOADER + default y + help + The kernel source tree includes a number of firmware 'blobs' + that are used by various drivers. The recommended way to + use these is to run "make firmware_install", which, after + converting ihex files to binary, copies all of the needed + binary files in firmware/ to /lib/firmware/ on your system so + that they can be loaded by userspace helpers on request. + + Enabling this option will build each required firmware blob + into the kernel directly, where request_firmware() will find + them without having to call out to userspace. This may be + useful if your root file system requires a device that uses + such firmware and do not wish to use an initrd. + + This single option controls the inclusion of firmware for + every driver that uses request_firmware() and ships its + firmware in the kernel source tree, which avoids a + proliferation of 'Include firmware for xxx device' options. + + Say 'N' and let firmware be loaded from userspace. + +config EXTRA_FIRMWARE + string "External firmware blobs to build into the kernel binary" + depends on FW_LOADER + help + This option allows firmware to be built into the kernel for the case + where the user either cannot or doesn't want to provide it from + userspace at runtime (for example, when the firmware in question is + required for accessing the boot device, and the user doesn't want to + use an initrd). + + This option is a string and takes the (space-separated) names of the + firmware files -- the same names that appear in MODULE_FIRMWARE() + and request_firmware() in the source. These files should exist under + the directory specified by the EXTRA_FIRMWARE_DIR option, which is + by default the firmware subdirectory of the kernel source tree. + + For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy + the usb8388.bin file into the firmware directory, and build the kernel. + Then any request_firmware("usb8388.bin") will be satisfied internally + without needing to call out to userspace. + + WARNING: If you include additional firmware files into your binary + kernel image that are not available under the terms of the GPL, + then it may be a violation of the GPL to distribute the resulting + image since it combines both GPL and non-GPL work. You should + consult a lawyer of your own before distributing such an image. + +config EXTRA_FIRMWARE_DIR + string "Firmware blobs root directory" + depends on EXTRA_FIRMWARE != "" + default "firmware" + help + This option controls the directory in which the kernel build system + looks for the firmware files listed in the EXTRA_FIRMWARE option. + The default is firmware/ in the kernel source tree, but by changing + this option you can point it elsewhere, such as /lib/firmware/ or + some other directory containing the firmware files. + +config FW_LOADER_USER_HELPER + bool + +config FW_LOADER_USER_HELPER_FALLBACK + bool "Fallback user-helper invocation for firmware loading" + depends on FW_LOADER + select FW_LOADER_USER_HELPER + help + This option enables / disables the invocation of user-helper + (e.g. udev) for loading firmware files as a fallback after the + direct file loading in kernel fails. The user-mode helper is + no longer required unless you have a special firmware file that + resides in a non-standard path. Moreover, the udev support has + been deprecated upstream. + + If you are unsure about this, say N here. + +config WANT_DEV_COREDUMP + bool + help + Drivers should "select" this option if they desire to use the + device coredump mechanism. + +config ALLOW_DEV_COREDUMP + bool "Allow device coredump" if EXPERT + default y + help + This option controls if the device coredump mechanism is available or + not; if disabled, the mechanism will be omitted even if drivers that + can use it are enabled. + Say 'N' for more sensitive systems or systems that don't want + to ever access the information to not have the code, nor keep any + data. + + If unsure, say Y. + +config DEV_COREDUMP + bool + default y if WANT_DEV_COREDUMP + depends on ALLOW_DEV_COREDUMP + +config DEBUG_DRIVER + bool "Driver Core verbose debug messages" + depends on DEBUG_KERNEL + help + Say Y here if you want the Driver core to produce a bunch of + debug messages to the system log. Select this if you are having a + problem with the driver core and want to see more of what is + going on. + + If you are unsure about this, say N here. + +config DEBUG_DEVRES + bool "Managed device resources verbose debug messages" + depends on DEBUG_KERNEL + help + This option enables kernel parameter devres.log. If set to + non-zero, devres debug messages are printed. Select this if + you are having a problem with devres or want to debug + resource management for a managed device. devres.log can be + switched on and off from sysfs node. + + If you are unsure about this, Say N here. + +config SYS_HYPERVISOR + bool + default n + +config GENERIC_CPU_DEVICES + bool + default n + +config GENERIC_CPU_AUTOPROBE + bool + +config SOC_BUS + bool + +source "drivers/base/regmap/Kconfig" + +config DMA_SHARED_BUFFER + bool + default n + select ANON_INODES + help + This option enables the framework for buffer-sharing between + multiple drivers. A buffer is associated with a file using driver + APIs extension; the file's descriptor can then be passed on to other + driver. + +config FENCE_TRACE + bool "Enable verbose FENCE_TRACE messages" + depends on DMA_SHARED_BUFFER + help + Enable the FENCE_TRACE printks. This will add extra + spam to the console log, but will make it easier to diagnose + lockup related problems for dma-buffers shared across multiple + devices. + +config DMA_CMA + bool "DMA Contiguous Memory Allocator" + depends on HAVE_DMA_CONTIGUOUS && CMA + help + This enables the Contiguous Memory Allocator which allows drivers + to allocate big physically-contiguous blocks of memory for use with + hardware components that do not support I/O map nor scatter-gather. + + You can disable CMA by specifying "cma=0" on the kernel's command + line. + + For more information see <include/linux/dma-contiguous.h>. + If unsure, say "n". + +if DMA_CMA +comment "Default contiguous memory area size:" + +config CMA_SIZE_MBYTES + int "Size in Mega Bytes" + depends on !CMA_SIZE_SEL_PERCENTAGE + default 0 if X86 + default 16 + help + Defines the size (in MiB) of the default memory area for Contiguous + Memory Allocator. If the size of 0 is selected, CMA is disabled by + default, but it can be enabled by passing cma=size[MG] to the kernel. + + +config CMA_SIZE_PERCENTAGE + int "Percentage of total memory" + depends on !CMA_SIZE_SEL_MBYTES + default 0 if X86 + default 10 + help + Defines the size of the default memory area for Contiguous Memory + Allocator as a percentage of the total memory in the system. + If 0 percent is selected, CMA is disabled by default, but it can be + enabled by passing cma=size[MG] to the kernel. + +choice + prompt "Selected region size" + default CMA_SIZE_SEL_MBYTES + +config CMA_SIZE_SEL_MBYTES + bool "Use mega bytes value only" + +config CMA_SIZE_SEL_PERCENTAGE + bool "Use percentage value only" + +config CMA_SIZE_SEL_MIN + bool "Use lower value (minimum)" + +config CMA_SIZE_SEL_MAX + bool "Use higher value (maximum)" + +endchoice + +config CMA_ALIGNMENT + int "Maximum PAGE_SIZE order of alignment for contiguous buffers" + range 4 12 + default 8 + help + DMA mapping framework by default aligns all buffers to the smallest + PAGE_SIZE order which is greater than or equal to the requested buffer + size. This works well for buffers up to a few hundreds kilobytes, but + for larger buffers it just a memory waste. With this parameter you can + specify the maximum PAGE_SIZE order for contiguous buffers. Larger + buffers will be aligned only to this specified order. The order is + expressed as a power of two multiplied by the PAGE_SIZE. + + For example, if your system defaults to 4KiB pages, the order value + of 8 means that the buffers will be aligned up to 1MiB only. + + If unsure, leave the default value "8". + +endif + +endmenu |