Yoctoレシピの書き方：.bbファイル作成ガイド

hello-world_1.0.bb      # hello-world バージョン1.0
myapp_2.3.1.bb          # myapp バージョン2.3.1
busybox_1.36.1.bb       # busybox バージョン1.36.1

# hello-world_1.0.bb

# ===== メタデータ =====
SUMMARY = "Hello World サンプル"
DESCRIPTION = "Yoctoレシピの学習用サンプルアプリケーション"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

# ===== ソースコードの取得 =====
SRC_URI = "file://hello.c"

# ===== ビルドディレクトリの設定 =====
S = "${WORKDIR}"

# ===== ビルド処理 =====
do_compile() {
    ${CC} ${CFLAGS} ${LDFLAGS} -o hello hello.c
}

# ===== インストール処理 =====
do_install() {
    install -d ${D}${bindir}
    install -m 0755 hello ${D}${bindir}
}

cd ~/yocto/poky
source oe-init-build-env build

# 新しいレイヤーを作成
cd ..
bitbake-layers create-layer meta-mylayer

# レイヤーをビルドに追加
cd build
bitbake-layers add-layer ../meta-mylayer

mkdir -p ../meta-mylayer/recipes-example/hello-world/files

// files/hello.c
#include <stdio.h>

int main(void) {
    printf("Hello from Yocto!\n");
    printf("This app was built with a custom recipe.\n");
    return 0;
}

# hello-world_1.0.bb
SUMMARY = "Hello World - Yoctoレシピ学習用サンプル"
DESCRIPTION = "Yoctoでカスタムレシピを作成する方法を学ぶためのサンプルアプリケーション"

LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "file://hello.c"

S = "${WORKDIR}"

do_compile() {
    ${CC} ${CFLAGS} ${LDFLAGS} -o hello hello.c
}

do_install() {
    install -d ${D}${bindir}
    install -m 0755 hello ${D}${bindir}
}

# 個別にレシピをビルド
bitbake hello-world

# ビルド成功のメッセージ
NOTE: Tasks Summary: Attempted 123 tasks of which 120 didn't need to be rerun

IMAGE_INSTALL:append = " hello-world"

bitbake core-image-minimal
runqemu qemux86-64 nographic

# ログイン後、helloコマンドを実行
root@qemux86-64:~# hello
Hello from Yocto!
This app was built with a custom recipe.

# nlohmann-json_3.11.3.bb
SUMMARY = "JSON for Modern C++"
DESCRIPTION = "Header-only JSON library for C++"
HOMEPAGE = "https://github.com/nlohmann/json"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://LICENSE.MIT;md5=f969127d7b7ed0a8a63c2bbeae002588"

# GitHubからソースを取得
SRC_URI = "git://github.com/nlohmann/json.git;protocol=https;branch=develop"

# 特定のコミットを指定（再現性のため必須）
SRCREV = "9cca280a4d0ccf0c08f47a99aa71d1b0e52f8d03"

# ソースの展開先（gitクローン時は ${WORKDIR}/git）
S = "${WORKDIR}/git"

inherit cmake

EXTRA_OECMAKE = "-DJSON_BuildTests=OFF"

# myapp-cmake_1.0.bb
SUMMARY = "My CMake App"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "git://github.com/user/myapp.git;protocol=https;branch=main"
SRCREV = "abc123def456..."
S = "${WORKDIR}/git"

# CMakeクラスを継承するだけでビルドが自動化される
inherit cmake

EXTRA_OECMAKE = "-DBUILD_TESTS=OFF -DCMAKE_BUILD_TYPE=Release"

# myapp-autotools_1.0.bb
SUMMARY = "My Autotools App"
LICENSE = "GPL-2.0-only"
LIC_FILES_CHKSUM = "file://COPYING;md5=..."

SRC_URI = "https://example.com/myapp-1.0.tar.gz"
SRC_URI[sha256sum] = "def456..."

inherit autotools

EXTRA_OECONF = "--disable-docs"

ERROR: License checksum mismatch...

md5sum LICENSE

ERROR: Fetcher failure: Unable to find file...

ERROR: Nothing PROVIDES 'hello-world'

ERROR: SRC_URI checksum mismatch...

sha256sum ダウンロードしたファイル.tar.gz

# myapp_1.0.bb — 依存関係の設定例
SUMMARY = "My App with Dependencies"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "file://myapp.c"
S = "${WORKDIR}"

# ビルド時: OpenSSLのヘッダとライブラリが必要
DEPENDS = "openssl"

# 実行時: OpenSSLの共有ライブラリが必要
RDEPENDS:${PN} = "openssl"

do_compile() {
    ${CC} ${CFLAGS} ${LDFLAGS} -o myapp myapp.c -lssl -lcrypto
}

do_install() {
    install -d ${D}${bindir}
    install -m 0755 myapp ${D}${bindir}
}

# myapp_1.0.bb
require myapp-common.inc

SRC_URI = "https://example.com/myapp-1.0.tar.gz"
SRC_URI[sha256sum] = "abc123..."

SRC_URI = "file://main.c \
           file://utils.c \
           file://utils.h \
           file://config.json \
           "

# Python式で変数を設定
DATEVAR = "${@time.strftime('%Y%m%d', time.gmtime())}"

python do_configure:prepend() {
    bb.note("Configuring with custom Python logic")
}

bitbake -c devshell hello-world

do_install() {
    install -d ${D}${sysconfdir}/myapp
    install -m 0644 ${WORKDIR}/myapp.conf ${D}${sysconfdir}/myapp/
}