diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 43cd1f15..ba541799 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,24 +1,28 @@
-name: Build
+name: Build native Zephyr samples
 
 on: [push, pull_request]
 
 jobs:
   build:
+    name: Build native Zephyr samples
     runs-on: ubuntu-latest
     container: zephyrprojectrtos/ci:latest
     env:
       CMAKE_PREFIX_PATH: /opt/toolchains
-      PR_NUMBER: ${{ github.event.number }}
+      CCACHE_IGNOREOPTIONS: -specs=*
+      REPOSITORY: ${{ github.event.pull_request.head.repo.full_name || github.repository }}
+      BRANCH: ${{ github.event.pull_request.head.ref || github.ref_name }}
     steps:
       - name: Initialize
         run: |
           mkdir build && cd build
-          west init -m https://github.com/${{ github.repository }}
-          cd modules/lib/ArduinoCore-zephyr/
-          git fetch origin ${{ github.ref }}
-          git checkout FETCH_HEAD
-          cd -
-          west update
+          west init -m https://github.com/${{ env.REPOSITORY }} --mr ${{ env.BRANCH }}
+          west update -o=--filter=tree:0
+
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2
+        with:
+          verbose: 1
 
       - name: Build fade
         working-directory: build
@@ -33,4 +37,4 @@ jobs:
       - name: Build adc
         working-directory: build
         run: |
-          west build -p -b arduino_nano_33_ble/nrf52840/sense modules/lib/ArduinoCore-zephyr/samples/analog_input
\ No newline at end of file
+          west build -p -b arduino_nano_33_ble/nrf52840/sense modules/lib/ArduinoCore-zephyr/samples/analog_input
diff --git a/.github/workflows/package_core.yml b/.github/workflows/package_core.yml
index ea7bd7ee..a2f6511d 100644
--- a/.github/workflows/package_core.yml
+++ b/.github/workflows/package_core.yml
@@ -1,53 +1,187 @@
-name: Package core
+name: Package, test and upload core
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - arduino
+  pull_request:
 
 jobs:
-  build:
+
+  package-core:
+    name: Build and package core
     runs-on: ubuntu-latest
     env:
       ZEPHYR_SDK_INSTALL_DIR: /opt/zephyr-sdk-0.16.8
+      CCACHE_IGNOREOPTIONS: -specs=*
+    outputs:
+      CORE_TAG: ${{ env.CORE_TAG }}
+      CORE_ARTIFACT: ${{ env.CORE_ARTIFACT }}
+      BOARD_NAMES: ${{ env.BOARD_NAMES }}
     steps:
       - name: Install toolchain
         working-directory: /opt
         run: |
           sudo apt-get update
-          sudo apt-get install -y --no-install-recommends git cmake wget python3-pip ninja-build
-          wget https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v0.16.8/zephyr-sdk-0.16.8_linux-x86_64_minimal.tar.xz
+          sudo apt-get install -y --no-install-recommends git cmake wget python3-pip ninja-build ccache
+          wget -nv https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v0.16.8/zephyr-sdk-0.16.8_linux-x86_64_minimal.tar.xz
           tar xf zephyr-sdk-0.16.8_linux-x86_64_minimal.tar.xz && cd zephyr-sdk-0.16.8 && ./setup.sh -t arm-zephyr-eabi -c
 
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          persist-credentials: false
 
       - name: Initialize
         run: |
-          ./extra/bootstrap.sh
-          ./extra/build_all.sh
-          ./extra/package.sh `git describe --always`
-          mv ../arduino-core-zephyr-llext* .
+          ./extra/bootstrap.sh -o=--filter=tree:0
+          echo "CORE_TAG=$(git describe --always)" >> "$GITHUB_ENV"
+          echo "CORE_ARTIFACT=ArduinoCore-zephyr-$(git describe --always)" >> "$GITHUB_ENV"
+          echo "BOARD_NAMES=[ $(cat boards.txt | grep '^[^#]*\.build\.variant' | cut -d '.' -f 1 | xargs printf '"%s",' | sed -e 's/,$//') ]" >> "$GITHUB_ENV"
+
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2
+        with:
+          verbose: 1
+
+      - name: Build variants
+        run: |
+          ./extra/build_all.sh -f
+
+      - name: Package
+        run: |
+          ./extra/package.sh ${{ env.CORE_TAG }}
+          mv ../${{ env.CORE_ARTIFACT }}.tar.bz2 .
 
       - name: Archive core
         uses: actions/upload-artifact@v4
         with:
-          name: Core
-          path: arduino-core-zephyr-llext*
+          name: ${{ env.CORE_ARTIFACT }}
+          path: ${{ env.CORE_ARTIFACT }}.tar.bz2
+
+  test-core:
+    name: Test arduino:zephyr:${{ matrix.board }}
+    runs-on: ubuntu-latest
+    needs: package-core
+    strategy:
+      matrix:
+        board: ${{ fromJSON( needs.package-core.outputs.BOARD_NAMES ) }}
+      fail-fast: false
+    env:
+      FQBN: arduino:zephyr:${{ matrix.board }}
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: ${{ needs.package-core.outputs.CORE_ARTIFACT }}
+
+      - name: Set up core
+        run: |
+          tar xf ${{ needs.package-core.outputs.CORE_ARTIFACT }}.tar.bz2
 
       - name: Create Blink sketch
         run: |
-          mkdir extra/Blink/
-          wget https://raw.githubusercontent.com/arduino/arduino-examples/refs/heads/main/examples/01.Basics/Blink/Blink.ino
-          mv Blink.ino extra/Blink/
+          mkdir Blink/
+          wget -nv https://raw.githubusercontent.com/arduino/arduino-examples/refs/heads/main/examples/01.Basics/Blink/Blink.ino -P Blink/
 
-      - name: Compile Blink
-        uses: arduino/compile-sketches@main
+      - name: Compile Blink for ${{ env.FQBN }}
+        uses: pillo79/compile-sketches@main
         with:
-          fqbn: arduino:zephyr:giga
+          fqbn: ${{ env.FQBN }}
           platforms: |
             # Use Board Manager to install the latest release of Arduino Zephyr Boards to get the toolchain
             - name: "arduino:zephyr"
               source-url: "https://downloads.arduino.cc/packages/package_zephyr_index.json"
-            - source-path: "./"
-              name: "arduino:zephyr"
-          sketch-paths: |
-            extra/Blink
+            - name: "arduino:zephyr"
+              source-path: "ArduinoCore-zephyr"
+          sketch-paths: Blink
           verbose: 'false'
           enable-deltas-report: 'false'
+          enable-warnings-report: 'true'
+          enable-warnings-log: 'true'
+
+      - name: Clean up log
+        run: |
+            sed -i -e 's!/home/runner/.arduino15/packages/arduino/hardware/zephyr/[^/]*/!!g' sketches-reports/*
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: test-report-${{ needs.package-core.outputs.CORE_TAG }}-${{ matrix.board }}
+          path: sketches-reports/*
+
+  collect-logs:
+    name: Test summary
+    runs-on: ubuntu-latest
+    needs:
+      - package-core
+      - test-core
+    if: ${{ !cancelled() && needs.package-core.result == 'success' }}
+    env:
+      BOARD_NAMES: ${{ needs.package-core.outputs.BOARD_NAMES }}
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          path: .
+          pattern: test-report-*
+          merge-multiple: true
+
+      - run: |
+          echo "### Core test results" >> "$GITHUB_STEP_SUMMARY"
+          for BOARD in $(echo $BOARD_NAMES | jq -cr '.[]'); do
+            FQBN="arduino:zephyr:$BOARD"
+            REPORT_FILE="arduino-zephyr-$BOARD.json"
+            if [ ! -f $REPORT_FILE ]; then
+              echo ":x: $BOARD - No report found?" >> "$GITHUB_STEP_SUMMARY"
+            else
+              REPORT=$(jq -cr '.boards[0].sketches[0]' $REPORT_FILE)
+              if ! $(echo $REPORT | jq -cr '.compilation_success') ; then
+                echo ":x: $BOARD - **Build failed**" >> "$GITHUB_STEP_SUMMARY"
+              else
+                WARNINGS=$(echo $REPORT | jq -cr '.warnings.current.absolute // 0')
+                if [ $WARNINGS -eq 0 ]; then
+                  echo ":white_check_mark: $BOARD - Build successful" >> "$GITHUB_STEP_SUMMARY"
+                else
+                  echo "<details><summary>:warning: $BOARD - $WARNINGS Warnings:</summary>" >> "$GITHUB_STEP_SUMMARY"
+                  echo >> "$GITHUB_STEP_SUMMARY"
+                  echo "\`\`\`" >> "$GITHUB_STEP_SUMMARY"
+                  echo $REPORT | jq -cr '.warnings_log[]' >> "$GITHUB_STEP_SUMMARY"
+                  echo "\`\`\`" >> "$GITHUB_STEP_SUMMARY"
+                  echo >> "$GITHUB_STEP_SUMMARY"
+                  echo "</details>" >> "$GITHUB_STEP_SUMMARY"
+                fi
+              fi
+            fi
+          done
+
+  publish-artifacts:
+    name: Publish artifacts
+    runs-on: ubuntu-latest
+    if: ${{ github.event_name == 'push' && github.repository == 'arduino/ArduinoCore-zephyr' }}
+    needs:
+      - package-core
+      - test-core
+    env:
+      CORE_ARTIFACT: ${{ needs.package-core.outputs.CORE_ARTIFACT }}
+      CORE_TAG: ${{ needs.package-core.outputs.CORE_TAG }}
+      PACKAGE_INDEX_JSON: zephyr-core-${{ needs.package-core.outputs.CORE_TAG }}.json
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: ${{ env.CORE_ARTIFACT }}
+
+      - name: Configure AWS credentials
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          role-to-assume: ${{ secrets.IAM_ROLE }}
+          aws-region: ${{ secrets.AWS_REGION }}
+
+      - name: Upload artifact
+        run: aws s3 sync ${{ env.CORE_ARTIFACT }}.tar.bz2 s3://${{ secrets.S3_BUCKET }}
+
+      - name: Prepare package index snippet
+        run: ./extra/gen_package_index_json.sh
+
+      - name: Archive package index snippet
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ env.PACKAGE_INDEX_JSON }}
+          path: ${{ env.PACKAGE_INDEX_JSON }}
diff --git a/extra/bootstrap.sh b/extra/bootstrap.sh
index f8a1e01d..f175a201 100755
--- a/extra/bootstrap.sh
+++ b/extra/bootstrap.sh
@@ -9,7 +9,7 @@ python3 -m venv venv
 source venv/bin/activate
 pip install west
 west init -l .
-west update
+west update "$@"
 west zephyr-export
 pip install -r ../zephyr/scripts/requirements-base.txt
 # download slim toolchain from https://github.com/zephyrproject-rtos/sdk-ng/releases/tag/v0.16.8
diff --git a/extra/build.sh b/extra/build.sh
index 379fe34a..d7bff7d5 100755
--- a/extra/build.sh
+++ b/extra/build.sh
@@ -13,10 +13,11 @@ if [ x$ZEPHYR_SDK_INSTALL_DIR == x"" ]; then
 fi
 
 if [[ $# -eq 0 ]]; then
-    board=arduino_giga_r1//m7
+	board=$(jq -cr '.[0].board' < ./extra/targets.json)
+	args=$(jq -cr '.[0].args' < ./extra/targets.json)
 else
-    board=$1
-    shift
+	board=$1
+	shift
 fi
 
 source venv/bin/activate
@@ -24,20 +25,13 @@ source venv/bin/activate
 ZEPHYR_BASE=$(west topdir)/zephyr
 
 # Get the variant name (NORMALIZED_BOARD_TARGET in Zephyr)
-tmpdir=$(mktemp -d)
-variant=$(cmake -DBOARD=$board -P extra/get_variant_name.cmake | grep 'VARIANT=' | cut -d '=' -f 2)
-rm -rf ${tmpdir}
+variant=$(extra/get_variant_name.sh $board)
 
 if [ -z "${variant}" ] ; then
 	echo "Failed to get variant name from '$board'"
 	exit 1
 fi
 
-echo && echo && echo
-echo ${variant}
-echo ${variant} | sed -e 's/./=/g'
-echo
-
 # Build the loader
 BUILD_DIR=build/${variant}
 VARIANT_DIR=variants/${variant}
diff --git a/extra/build_all.sh b/extra/build_all.sh
index 5d7c7b8f..e66542e4 100755
--- a/extra/build_all.sh
+++ b/extra/build_all.sh
@@ -1,12 +1,58 @@
-# Update this file if a new board gets supported
-
-set -e
-
-./extra/build.sh arduino_giga_r1//m7 --shield giga_display_shield
-./extra/build.sh arduino_nano_33_ble//sense
-./extra/build.sh arduino_nicla_sense_me
-./extra/build.sh arduino_portenta_c33
-./extra/build.sh arduino_portenta_h7@1.0.0//m7
-./extra/build.sh ek_ra8d1
-./extra/build.sh frdm_mcxn947/mcxn947/cpu0
-./extra/build.sh frdm_rw612
+#!/bin/bash
+
+FORCE=false
+
+while getopts "hfl" opt; do
+	case $opt in
+		h)
+			echo "Usage: $0 [-hfl]"
+			echo "  -h  Show this help message"
+			echo "  -f  Force build all targets"
+			exit 0
+			;;
+		f)
+			FORCE=true
+			;;
+		*)
+			echo "Invalid option: -$OPTARG" >&2
+			exit 1
+			;;
+	esac
+done
+
+if [ ! -z "$GITHUB_STEP_SUMMARY" ] ; then
+	echo "### Variant build results:" >> "$GITHUB_STEP_SUMMARY"
+fi
+
+jq -cr '.[]' < ./extra/targets.json | while read -r item; do
+	board=$(jq -cr '.board // ""' <<< "$item")
+	args=$(jq -cr '.args // ""' <<< "$item")
+
+	variant=$(extra/get_variant_name.sh "$board" || echo "$board")
+	if [ -z "$GITHUB_STEP_SUMMARY" ] ; then
+		echo && echo
+		echo ${variant}
+		echo ${variant} | sed -e 's/./=/g'
+	else
+		echo "::group::=== ${variant} ==="
+	fi
+
+	./extra/build.sh "$board" $args
+	result=$?
+
+	if [ -z "$GITHUB_STEP_SUMMARY" ] ; then
+		echo
+		echo "${variant} result: $result"
+	else
+		echo "::endgroup::"
+		if [ $result -eq 0 ] ; then
+			echo "- :white_check_mark: \`${variant}\`" >> "$GITHUB_STEP_SUMMARY"
+		else
+			echo "^^^$(echo ${variant} | sed -e 's/./^/g')^^  FAILED with $result!"
+			echo "- :x: \`${variant}\`" >> "$GITHUB_STEP_SUMMARY"
+		fi
+	fi
+	[ $result -ne 0 ] && ! $FORCE && exit $result
+done
+
+exit 0
diff --git a/extra/gen_package_index_json.sh b/extra/gen_package_index_json.sh
new file mode 100755
index 00000000..bcaee2cb
--- /dev/null
+++ b/extra/gen_package_index_json.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+if [ -z "$CORE_TAG" ]; then
+  echo "This script can be used in Github CI only."
+  exit 1
+fi
+
+export ARTIFACT_HASH=$(sha256sum $CORE_ARTIFACT)
+export ARTIFACT_SIZE=$(stat -c %s $CORE_ARTIFACT)
+
+envsubst < extra/zephyr-core-template.json > $PACKAGE_INDEX_JSON
diff --git a/extra/get_variant_name.sh b/extra/get_variant_name.sh
new file mode 100755
index 00000000..a1eaba45
--- /dev/null
+++ b/extra/get_variant_name.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+set -e
+
+source venv/bin/activate
+
+# Get the variant name (NORMALIZED_BOARD_TARGET in Zephyr)
+tmpdir=$(mktemp -d)
+variant=$(cmake "-DBOARD=$1" -P extra/get_variant_name.cmake 2>/dev/null | grep 'VARIANT=' | cut -d '=' -f 2)
+rm -rf ${tmpdir}
+
+echo $variant
diff --git a/extra/package.sh b/extra/package.sh
index b6459f3f..5e88ce3c 100755
--- a/extra/package.sh
+++ b/extra/package.sh
@@ -10,4 +10,4 @@ FOLDER=`basename $PWD`
 VERSION=$1
 
 cd ..
-tar  --exclude=extras/** --exclude=.git* --exclude=build --exclude=venv --exclude=samples -cjhf arduino-core-zephyr-llext-${VERSION}.tar.bz2 $FOLDER
\ No newline at end of file
+tar  --exclude=extras/** --exclude=.git* --exclude=build --exclude=venv --exclude=samples -cjhf ArduinoCore-zephyr-${VERSION}.tar.bz2 $FOLDER
diff --git a/extra/targets.json b/extra/targets.json
new file mode 100755
index 00000000..156aa6e9
--- /dev/null
+++ b/extra/targets.json
@@ -0,0 +1,10 @@
+[
+	{ "board": "arduino_giga_r1//m7", "args": "--shield giga_display_shield" },
+	{ "board": "arduino_nano_33_ble//sense" },
+	{ "board": "arduino_nicla_sense_me" },
+	{ "board": "arduino_portenta_c33" },
+	{ "board": "arduino_portenta_h7@1.0.0//m7" },
+	{ "board": "ek_ra8d1" },
+	{ "board": "frdm_mcxn947/mcxn947/cpu0" },
+	{ "board": "frdm_rw612" }
+]
diff --git a/extra/zephyr-core-template.json b/extra/zephyr-core-template.json
new file mode 100644
index 00000000..7f4f72d1
--- /dev/null
+++ b/extra/zephyr-core-template.json
@@ -0,0 +1,66 @@
+{
+  "packages": [
+    {
+      "platforms": [
+        {
+          "name": "Arduino Zephyr Boards",
+          "architecture": "zephyr",
+          "version": "$CORE_TAG",
+          "category": "Arduino",
+          "url": "https://downloads.arduino.cc/cores/zephyr/${CORE_ARTIFACT}.tar.bz2",
+          "archiveFileName": "${CORE_ARTIFACT}.tar.bz2",
+          "checksum": "SHA-256:${ARTIFACT_HASH}",
+          "size": "${ARTIFACT_SIZE}",
+          "help": {
+            "online": "https://www.arduino.cc/en/Reference/HomePage"
+          },
+          "boards": [
+            {
+              "name": "Arduino Giga"
+            },
+            {
+              "name": "Arduino Nano 33 BLE"
+            },
+            {
+              "name": "Arduino Portenta H7"
+            },
+            {
+              "name": "Arduino Portenta C33"
+            },
+            {
+              "name": "Renesas EK_RA8D1"
+            },
+            {
+              "name": "NXP FRDM MCXN947"
+            },
+            {
+              "name": "NXP FRDM RW612"
+            }
+          ],
+          "toolsDependencies": [
+            {
+              "packager": "zephyr",
+              "name": "arm-zephyr-eabi",
+              "version": "0.16.8"
+            },
+            {
+              "packager": "arduino",
+              "name": "dfu-util",
+              "version": "0.11.0-arduino5"
+            },
+            {
+              "packager": "arduino",
+              "name": "bossac",
+              "version": "1.9.1-arduino2"
+            },
+            {
+              "packager": "arduino",
+              "name": "zephyr-post-build-tool",
+              "version": "0.1.0"
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}