Example layout

下面是一个使用 br2-external tree 完整例子的目录树 （这个例子包含上面描述的内容，但这个例子仅仅是一个演示）

/path/to/br2-ext-tree/

|- external.desc

| |name: BAR_42

| |desc: Example br2-external tree

| `----

|

|- Config.in

| |source "$BR2_EXTERNAL_BAR_42_PATH/toolchain/toolchain-external-mine/Config.in.options"

| |source "$BR2_EXTERNAL_BAR_42_PATH/package/pkg-1/Config.in"

| |source "$BR2_EXTERNAL_BAR_42_PATH/package/pkg-2/Config.in"

| |source "$BR2_EXTERNAL_BAR_42_PATH/package/my-jpeg/Config.in"

| |

| |config BAR_42_FLASH_ADDR

| | hex "my-board flash address"

| | default 0x10AD

| `----

|

|- external.mk

| |include $(sort $(wildcard $(BR2_EXTERNAL_BAR_42_PATH)/package/*/*.mk))

| |include $(sort $(wildcard $(BR2_EXTERNAL_BAR_42_PATH)/toolchain/*/*.mk))

| |

| |flash-my-board:

| | $(BR2_EXTERNAL_BAR_42_PATH)/board/my-board/flash-image \

| | --image $(BINARIES_DIR)/image.bin \

| | --address $(BAR_42_FLASH_ADDR)

| `----

|

|- package/pkg-1/Config.in

| |config BR2_PACKAGE_PKG_1

| | bool "pkg-1"

| | help

| | Some help about pkg-1

| `----

|- package/pkg-1/pkg-1.hash

|- package/pkg-1/pkg-1.mk

| |PKG_1_VERSION = 1.2.3

| |PKG_1_SITE = /some/where/to/get/pkg-1

| |PKG_1_LICENSE = blabla

| |

| |define PKG_1_INSTALL_INIT_SYSV

| | $(INSTALL) -D -m 0755 $(PKG_1_PKGDIR)/S99my-daemon \

| | $(TARGET_DIR)/etc/init.d/S99my-daemon

| |endef

| |

| |$(eval $(autotools-package))

| `----

|- package/pkg-1/S99my-daemon

|

|- package/pkg-2/Config.in

|- package/pkg-2/pkg-2.hash

|- package/pkg-2/pkg-2.mk

|

|- provides/jpeg.in

| |config BR2_PACKAGE_MY_JPEG

| | bool "my-jpeg"

| `----

|- package/my-jpeg/Config.in

| |config BR2_PACKAGE_PROVIDES_JPEG

| | default "my-jpeg" if BR2_PACKAGE_MY_JPEG

| `----

|- package/my-jpeg/my-jpeg.mk

| |# This is a normal package .mk file

| |MY_JPEG_VERSION = 1.2.3

| |MY_JPEG_SITE = https://example.net/some/place

| |MY_JPEG_PROVIDES = jpeg

| |$(eval $(autotools-package))

| `----

|

|- provides/init.in

| |config BR2_INIT_MINE

| | bool "my custom init"

| | select BR2_PACKAGE_MY_INIT

| | select BR2_PACKAGE_SKELETON_INIT_MINE if BR2_ROOTFS_SKELETON_DEFAULT

| `----

|

|- provides/skeleton.in

| |config BR2_ROOTFS_SKELETON_MINE

| | bool "my custom skeleton"

| | select BR2_PACKAGE_SKELETON_MINE

| `----

|- package/skeleton-mine/Config.in

| |config BR2_PACKAGE_SKELETON_MINE

| | bool

| | select BR2_PACKAGE_HAS_SKELETON

| |

| |config BR2_PACKAGE_PROVIDES_SKELETON

| | default "skeleton-mine" if BR2_PACKAGE_SKELETON_MINE

| `----

|- package/skeleton-mine/skeleton-mine.mk

| |SKELETON_MINE_ADD_TOOLCHAIN_DEPENDENCY = NO

| |SKELETON_MINE_ADD_SKELETON_DEPENDENCY = NO

| |SKELETON_MINE_PROVIDES = skeleton

| |SKELETON_MINE_INSTALL_STAGING = YES

| |$(eval $(generic-package))

| `----

|

|- provides/toolchains.in

| |config BR2_TOOLCHAIN_EXTERNAL_MINE

| | bool "my custom toolchain"

| | depends on BR2_some_arch

| | select BR2_INSTALL_LIBSTDCPP

| `----

|- toolchain/toolchain-external-mine/Config.in.options

| |if BR2_TOOLCHAIN_EXTERNAL_MINE

| |config BR2_TOOLCHAIN_EXTERNAL_PREFIX

| | default "arch-mine-linux-gnu"

| |config BR2_PACKAGE_PROVIDES_TOOLCHAIN_EXTERNAL

| | default "toolchain-external-mine"

| |endif

| `----

|- toolchain/toolchain-external-mine/toolchain-external-mine.mk

| |TOOLCHAIN_EXTERNAL_MINE_SITE = https://example.net/some/place

| |TOOLCHAIN_EXTERNAL_MINE_SOURCE = my-toolchain.tar.gz

| |$(eval $(toolchain-external-package))

| `----

|

|- linux/Config.ext.in

| |config BR2_LINUX_KERNEL_EXT_EXAMPLE_DRIVER

| | bool "example-external-driver"

| | help

| | Example external driver

| |---

|- linux/linux-ext-example-driver.mk

|

|- configs/my-board_defconfig

| |BR2_GLOBAL_PATCH_DIR="$(BR2_EXTERNAL_BAR_42_PATH)/patches/"

| |BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_BAR_42_PATH)/board/my-board/overlay/"

| |BR2_ROOTFS_POST_IMAGE_SCRIPT="$(BR2_EXTERNAL_BAR_42_PATH)/board/my-board/post-image.sh"

| |BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_BAR_42_PATH)/board/my-board/kernel.config"

| `----

|

|- patches/linux/0001-some-change.patch

|- patches/linux/0002-some-other-change.patch

|- patches/busybox/0001-fix-something.patch

|

|- board/my-board/kernel.config

|- board/my-board/overlay/var/www/index.html

|- board/my-board/overlay/var/www/my.css

|- board/my-board/flash-image

`- board/my-board/post-image.sh

|#!/bin/sh

|generate-my-binary-image \

| --root ${BINARIES_DIR}/rootfs.tar \

| --kernel ${BINARIES_DIR}/zImage \

| --dtb ${BINARIES_DIR}/my-board.dtb \

| --output ${BINARIES_DIR}/image.bin

`----

该 br2-external tree 将会在 menuconfig 中可见 ，如下所示：

External options --->

*** Example br2-external tree (in /path/to/br2-ext-tree/)

[ ] pkg-1

[ ] pkg-2

(0x10AD) my-board flash address

如果你使用超过一个 br2-external tree，那么 menuconfig 的输出将会像下面这样（假设第二个的名字是 FOO_27 但是在 external.desc 中没有 desc: 字段):

External options --->

Example br2-external tree --->

*** Example br2-external tree (in /path/to/br2-ext-tree)

[ ] pkg-1

[ ] pkg-2

(0x10AD) my-board flash address

FOO_27 --->

*** FOO_27 (in /path/to/another-br2-ext)

[ ] foo

[ ] bar

此外，jpeg provider 也将出现在 jpeg 的选择列表中:

Target packages --->

Libraries --->

Graphics --->

[*] jpeg support

jpeg variant () --->

( ) jpeg

( ) jpeg-turbo

*** jpeg from: Example br2-external tree ***

(X) my-jpeg

*** jpeg from: FOO_27 ***

( ) another-jpeg

Toolchain 中的配置也类似：

Toolchain --->

Toolchain () --->

( ) Custom toolchain

*** Toolchains from: Example br2-external tree ***

(X) my custom toolchain

注意： toolchain 的选项 toolchain/toolchain-external-mine/Config.in.options 将不会出现在 Toolchain 的菜单中， 它们必须显式的包含在 br2-external 的顶级 Config.in 中，而配置则会出现在 External options 菜单中 .