ci: Add CI pipeline

ci/Jenkinsfile

@@ -0,0 +1,77 @@
+// vim: set ft=groovy :
+
+pipeline {
+    agent {
+        dockerfile {
+            dir 'ci'
+            args '''
+            -v /etc/ssh/ssh_known_hosts:/etc/ssh/ssh_known_hosts
+            --pids-limit 16384
+            '''
+            additionalBuildArgs '''\
+            --build-arg UID=$(id -u) \
+            --build-arg GID=$(id -g) \
+            '''
+        }
+    }
+
+    options {
+        buildDiscarder logRotator(numToKeepStr: '5')
+        disableConcurrentBuilds()
+    }
+
+    triggers {
+        pollSCM ''
+    }
+
+    parameters {
+        booleanParam \
+            name: 'Clean',
+            description: 'Clean the workspace and perform a full rebuild'
+    }
+
+    environment {
+        BUILDROOT_SRC = "${env.WORKSPACE}/buildroot"
+    }
+
+    stages {
+        stage('Prepare') {
+            steps {
+                script {
+                    if (params.Clean) {
+                        sh 'rm -rf _build'
+                    }
+                }
+                checkout poll: false, scm: [
+                    $class: 'GitSCM',
+                    branches: [[name: '2022.05.x']],
+                    doGenerateSubmoduleConfigurations: false,
+                    userRemoteConfigs: [[url: 'git://git.buildroot.net/buildroot']],
+                    extensions: [
+                        [
+                            $class: 'RelativeTargetDirectory',
+                            relativeTargetDir: 'buildroot',
+                        ],
+                    ],
+                ]
+            }
+        }
+
+        stage('Build') {
+            parallel {
+                stage('Build Initramfs') {
+                    steps {
+                        sh 'make initramfs'
+                    }
+                }
+
+                stage('Build Rootfs') {
+                    steps {
+                        sh 'make rootfs'
+                    }
+                }
+            }
+        }
+
+    }
+}