buildroot/linux/Config.in

menu "Kernel"

config BR2_LINUX_KERNEL
	bool "Linux Kernel"
	help
	  Enable this option if you want to build a Linux kernel for
	  your embedded device

if BR2_LINUX_KERNEL

#
# Version selection. We provide the choice between:
#
#  1. A single fairly recent stable kernel version
#  2. In case an internal toolchain has been built, the same kernel
#     version as the kernel headers
#  3. A custom stable version
#  4. A custom tarball
#
choice
	prompt "Kernel version"

config BR2_LINUX_KERNEL_LATEST_VERSION
	bool "4.1.2"

config BR2_LINUX_KERNEL_SAME_AS_HEADERS
	bool "Same as toolchain kernel headers"
	depends on BR2_TOOLCHAIN_BUILDROOT
	help
	  This option will re-use the same kernel sources as the one
	  that have been used for the kernel headers of the
	  cross-compiling toolchain. Having the same version for the
	  kernel running on the system and for the kernel headers is
	  not a requirement, but using the same version allows to
	  download only one tarball of the kernel sources.

config BR2_LINUX_KERNEL_CUSTOM_VERSION
	bool "Custom version"
	help
	  This option allows to use a specific official version from
	  kernel.org, like 2.6.x, 2.6.x.y, 3.x.y, ...

	  Note: you cannot use this option to select a _longterm_ 2.6
	  kernel, because these kernels are not located at the standard
	  URL at kernel.org. Instead, select "Custom tarball" and
	  specify the right URL directly.

config BR2_LINUX_KERNEL_CUSTOM_TARBALL
	bool "Custom tarball"
	help
	  This option allows to specify a URL pointing to a kernel source
	  tarball. This URL can use any protocol recognized by Buildroot,
	  like http://, ftp://, file:// or scp://.

	  When pointing to a local tarball using file://, you may want to
	  use a make variable like $(TOPDIR) to reference the root of the
	  Buildroot tree.

config BR2_LINUX_KERNEL_CUSTOM_GIT
	bool "Custom Git repository"
	help
	  This option allows Buildroot to get the Linux kernel source
	  code from a Git repository.

config BR2_LINUX_KERNEL_CUSTOM_HG
	bool "Custom Mercurial repository"
	help
	  This option allows Buildroot to get the Linux kernel source
	  code from a Mercurial repository.

config BR2_LINUX_KERNEL_CUSTOM_LOCAL
	bool "Local directory"
	help
	  This option allows Buildroot to get the Linux kernel source
	  code from a local directory.

endchoice

config BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE
	string "Kernel version"
	depends on BR2_LINUX_KERNEL_CUSTOM_VERSION

config BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION
	string "URL of custom kernel tarball"
	depends on BR2_LINUX_KERNEL_CUSTOM_TARBALL

if BR2_LINUX_KERNEL_CUSTOM_GIT || BR2_LINUX_KERNEL_CUSTOM_HG

config BR2_LINUX_KERNEL_CUSTOM_REPO_URL
	string "URL of custom repository"
	default BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL \
		if BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL != ""  # legacy

config BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION
	string "Custom repository version"
	default BR2_LINUX_KERNEL_CUSTOM_GIT_VERSION \
		if BR2_LINUX_KERNEL_CUSTOM_GIT_VERSION != ""  # legacy
	help
	  Revision to use in the typical format used by Git/Mercurial
	  E.G. a sha id, a tag, branch, ..

endif

config BR2_LINUX_KERNEL_CUSTOM_LOCAL_PATH
	string "Path to the local directory"
	depends on BR2_LINUX_KERNEL_CUSTOM_LOCAL
	help
	  Path to the local directory with the Linux kernel source code.

config BR2_LINUX_KERNEL_VERSION
	string
	default "4.1.2" if BR2_LINUX_KERNEL_LATEST_VERSION
	default BR2_DEFAULT_KERNEL_HEADERS if BR2_LINUX_KERNEL_SAME_AS_HEADERS
	default BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE \
		if BR2_LINUX_KERNEL_CUSTOM_VERSION
	default "custom" if BR2_LINUX_KERNEL_CUSTOM_TARBALL
	default BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION \
		if BR2_LINUX_KERNEL_CUSTOM_GIT || BR2_LINUX_KERNEL_CUSTOM_HG
	default "custom" if BR2_LINUX_KERNEL_CUSTOM_LOCAL

#
# Patch selection
#

config BR2_LINUX_KERNEL_PATCH
	string "Custom kernel patches"
	depends on !BR2_LINUX_KERNEL_CUSTOM_LOCAL
	help
	  A space-separated list of patches to apply to the
	  kernel. Each patch can be described as an URL, a local file
	  path, or a directory. In the case of a directory, all files
	  matching *.patch in the directory will be applied.

#
# Configuration selection
#

choice
	prompt "Kernel configuration"
	default BR2_LINUX_KERNEL_USE_DEFCONFIG

config BR2_LINUX_KERNEL_USE_DEFCONFIG
	bool "Using an in-tree defconfig file"

config BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG
	bool "Using a custom (def)config file"

endchoice

config BR2_LINUX_KERNEL_DEFCONFIG
	string "Defconfig name"
	depends on BR2_LINUX_KERNEL_USE_DEFCONFIG
	help
	  Name of the kernel defconfig file to use, without the
	  trailing _defconfig.  The defconfig is located in
	  arch/<arch>/configs in the kernel tree.

config BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE
	string "Configuration file path"
	depends on BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG
	help
	  Path to the kernel configuration file

	  Note: this can be a defconfig file or a complete .config file,
	  which can later be saved back with make linux-update-(def)config.

config BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES
	string "Additional configuration fragment files"
	help
	  A space-separated list of kernel configuration fragment files,
	  that will be merged to the main kernel configuration file.

#
# Binary format
#

config BR2_LINUX_KERNEL_UBOOT_IMAGE
	bool

choice
	prompt "Kernel binary format"

config BR2_LINUX_KERNEL_UIMAGE
	bool "uImage"
	depends on BR2_arc || BR2_arm || BR2_armeb || BR2_bfin || \
		   BR2_powerpc || BR2_powerpc64 || BR2_powerpc64le || \
		   BR2_sh || BR2_sh64 || BR2_mips || BR2_mipsel || \
		   BR2_mips64 || BR2_mips64el
	select BR2_LINUX_KERNEL_UBOOT_IMAGE

config BR2_LINUX_KERNEL_APPENDED_UIMAGE
	bool "uImage with appended DT"
	depends on BR2_arm || BR2_armeb
	select BR2_LINUX_KERNEL_DTS_SUPPORT
	select BR2_LINUX_KERNEL_APPENDED_DTB
	select BR2_LINUX_KERNEL_UBOOT_IMAGE

config BR2_LINUX_KERNEL_BZIMAGE
	bool "bzImage"
	depends on BR2_i386 || BR2_x86_64

config BR2_LINUX_KERNEL_ZIMAGE
	bool "zImage"
	depends on BR2_arm || BR2_armeb || BR2_powerpc || \
		   BR2_powerpc64 || BR2_powerpc64le || BR2_sparc || \
		   BR2_sh || BR2_sh64 || BR2_xtensa

config BR2_LINUX_KERNEL_APPENDED_ZIMAGE
	bool "zImage with appended DT"
	depends on BR2_arm || BR2_armeb
	select BR2_LINUX_KERNEL_DTS_SUPPORT
	select BR2_LINUX_KERNEL_APPENDED_DTB

config BR2_LINUX_KERNEL_CUIMAGE
	bool "cuImage"
	depends on BR2_powerpc
	select BR2_LINUX_KERNEL_UBOOT_IMAGE
	select BR2_LINUX_KERNEL_DTS_SUPPORT
	select BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT

config BR2_LINUX_KERNEL_SIMPLEIMAGE
	bool "simpleImage"
	depends on BR2_microblaze
	select BR2_LINUX_KERNEL_UBOOT_IMAGE
	select BR2_LINUX_KERNEL_DTS_SUPPORT
	select BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT

config BR2_LINUX_KERNEL_LINUX_BIN
	bool "linux.bin"
	depends on BR2_microblaze
	select BR2_LINUX_KERNEL_UBOOT_IMAGE

config BR2_LINUX_KERNEL_VMLINUX_BIN
	bool "vmlinux.bin"
	depends on BR2_mips || BR2_mipsel || BR2_sh || BR2_sh64

config BR2_LINUX_KERNEL_VMLINUX
	bool "vmlinux"

config BR2_LINUX_KERNEL_VMLINUZ
	bool "vmlinuz"
	depends on BR2_mips || BR2_mipsel

config BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM
	bool "custom target"
	help
	  For certain cases a board-specific target image must be
	  used.  For example, on powerPC where the OpenFirmware
	  description is attached in a board-specific kernel image
	  target like 'cuImage.mpc8379_rdb'.

	  Select this option and specify the make target in "Kernel
	  image target name".

endchoice

config BR2_LINUX_KERNEL_IMAGE_TARGET_NAME
	string "Kernel image target name"
	depends on BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM
	help
	  Specify the kernel make target to build the kernel that you
	  need.

config BR2_LINUX_KERNEL_IMAGE_NAME
	string "Kernel image name"
	depends on BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM
	help
	  The filename of the kernel image, if it is different from the
	  make target (above). Only Xtensa uses a filename different from
	  the make target. Defaults to BR2_LINUX_KERNEL_IMAGE_TARGET_NAME.

	  If unsure, leave it empty.

config BR2_LINUX_KERNEL_UIMAGE_LOADADDR
	string "load address (for 3.7+ multi-platform image)"
	depends on BR2_arm || BR2_armeb
	depends on BR2_LINUX_KERNEL_UIMAGE || BR2_LINUX_KERNEL_APPENDED_UIMAGE
	help
	  If your ARM system's Linux kernel is configured with the new (3.7+)
	  multi-architecture support (CONFIG_ARCH_MULTIPLATFORM=y in your
	  kernel config), then it is necessary to specify a kernel load address
	  when building the uImage. This should be a hexadecimal string
	  beginning with 0x, for example: 0x00008000.

	  If unsure, let this option empty.

config BR2_LINUX_KERNEL_DTS_SUPPORT
	bool "Build a Device Tree Blob (DTB)"
	help
	  Compile one or more device tree sources into device tree blobs.
	  Select the dts files to compile in the options below.

if BR2_LINUX_KERNEL_DTS_SUPPORT

# We have mainly three cases when it comes to device tree support:
#   1) We don't want any support at all. Then the ..DTS_SUPPORT
#      variable won't be set
#   2) We want device tree support, so we need the user to enter the
#      device tree name or the path to the custom device he uses, but
#      the kernel abstracts this from us and only build an image that
#      looks like a regular kernel image. In this case, we only need
#      to derive the kernel image name from the given device tree
#      name, and all the rest is as usual
#   3) We want device tree support, but the kernel requires us to
#      build the device tree blob separately. In this case, some
#      more logic will be needed.
# The variable below address the second case, were you only want
# limited actions from buildroot.
config BR2_LINUX_KERNEL_DTB_IS_SELF_BUILT
	bool

config BR2_LINUX_KERNEL_APPENDED_DTB
	bool

choice
	prompt "Device tree source"
	default BR2_LINUX_KERNEL_USE_INTREE_DTS

config BR2_LINUX_KERNEL_USE_INTREE_DTS
	bool "Use a device tree present in the kernel."
	help
	  Use a device tree source distributed with
	  the kernel sources. The dts files are located
	  in the arch/<arch>/boot/dts folder.

config BR2_LINUX_KERNEL_USE_CUSTOM_DTS
	bool "Use a custom device tree file"
	help
	  Use a custom device tree file, i.e, a device
	  tree file that does not belong to the kernel
	  source tree.
endchoice

config BR2_LINUX_KERNEL_INTREE_DTS_NAME
	string "Device Tree Source file names"
	depends on BR2_LINUX_KERNEL_USE_INTREE_DTS
	help
	  Name of the device tree source file, without
	  the trailing .dts. You can provide a list of
	  dts files to build, separated by spaces.

config BR2_LINUX_KERNEL_CUSTOM_DTS_PATH
	string "Device Tree Source file paths"
	depends on BR2_LINUX_KERNEL_USE_CUSTOM_DTS
	help
	  Path to the device tree source files. You can
	  provide a list of dts paths to copy and build,
	  separated by spaces.

endif

config BR2_LINUX_KERNEL_INSTALL_TARGET
	bool "Install kernel image to /boot in target"
	depends on !BR2_TARGET_ROOTFS_INITRAMFS
	help
	  Select this option to have the kernel image installed to
	  /boot in the target root filesystem, as is typically done on
	  x86/x86_64 systems.

	  Note that this option also installs the Device Tree Blobs to
	  /boot if DTBs have been generated by the kernel build
	  process.

# Linux extensions
source "linux/Config.ext.in"

endif # BR2_LINUX_KERNEL

endmenu