diff --git a/.github/workflows/main_build.yml b/.github/workflows/main_build.yml
index e83d2f8..1e3b0f5 100644
--- a/.github/workflows/main_build.yml
+++ b/.github/workflows/main_build.yml
@@ -57,13 +57,50 @@ jobs:
         id: detect
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # Pass PR body as an env var to avoid embedding ${{ }} expressions
+          # inside the run: | block at column-0 (which terminates the YAML
+          # block scalar prematurely and causes a static YAML parse error).
+          PR_BODY: ${{ github.event.pull_request.body }}
         run: |
-          # Resolve explicit board list from workflow_dispatch input or repository_dispatch payload.
+          # ── Priority order for board selection ──────────────────────────────
+          # 1. workflow_dispatch input  →  explicit user choice
+          # 2. repository_dispatch payload  →  caller-specified list
+          # 3. pull_request event  →  parse "boards: <list>" from PR body,
+          #                           fall back to default fast-CI set,
+          #                           or "all" to build every board
+          # 4. everything else (schedule, push)  →  auto-detect from HAOS repo
+          # ────────────────────────────────────────────────────────────────────
+
+          PR_DEFAULT_BOARDS="generic_aarch64,generic_x86_64,rpi4_64"
+
           BOARDS_INPUT="${{ github.event.inputs.boards }}"
+
           if [[ -z "${BOARDS_INPUT}" && "${{ github.event_name }}" == "repository_dispatch" ]]; then
             BOARDS_INPUT="${{ github.event.client_payload.boards }}"
           fi
 
+          if [[ -z "${BOARDS_INPUT}" && "${{ github.event_name }}" == "pull_request" ]]; then
+            # Extract "boards: <value>" from the PR body (case-insensitive, first match).
+            # PR_BODY is injected via env: above to avoid YAML block-scalar issues.
+            BOARDS_INPUT=$(echo "${PR_BODY}" \
+              | grep -iE '^[[:space:]]*boards[[:space:]]*:[[:space:]]*' \
+              | head -1 \
+              | sed -E 's/^[[:space:]]*boards[[:space:]]*:[[:space:]]*//i' \
+              | tr -d '\r')
+
+            if [[ -z "${BOARDS_INPUT}" ]]; then
+              # No "boards:" line in PR body — use the default fast-CI set.
+              BOARDS_INPUT="${PR_DEFAULT_BOARDS}"
+              echo "[INFO] PR body has no 'boards:' line — using default: ${BOARDS_INPUT}"
+            elif [[ "${BOARDS_INPUT,,}" == "all" ]]; then
+              # Explicit "all" — clear the input so the auto-detect path runs below.
+              BOARDS_INPUT=""
+              echo "[INFO] PR body specifies 'all' — detecting all boards from HAOS repo."
+            else
+              echo "[INFO] PR body specifies boards: ${BOARDS_INPUT}"
+            fi
+          fi
+
           if [[ -n "${BOARDS_INPUT}" ]]; then
             # Convert comma-separated list to a sorted JSON array, stripping whitespace.
             BOARDS=$(echo "${BOARDS_INPUT}" \
@@ -409,9 +446,12 @@ jobs:
           if [[ -d "${RPI_MEDIA}/rp1-cfe" && -d "${RPI_MEDIA}/rp1_cfe" ]]; then
             echo "[INFO] Both rp1-cfe/ and rp1_cfe/ found — removing legacy rp1-cfe/"
             rm -rf "${RPI_MEDIA}/rp1-cfe"
-            # Drop the legacy entry from the parent Makefile to avoid dangling obj- lines.
+            # Drop the legacy entry from both Makefile (obj- line) and Kconfig
+            # (source line). olddefconfig reads Kconfig before any compilation,
+            # so both files must be cleaned up or it fails with "can't open file".
             sed -i '/rp1-cfe/d' "${RPI_MEDIA}/Makefile" || true
-            echo "[INFO] rp1-cfe/ removed successfully."
+            sed -i '/rp1-cfe/d' "${RPI_MEDIA}/Kconfig"  || true
+            echo "[INFO] rp1-cfe/ removed and parent Makefile/Kconfig patched."
           else
             echo "[INFO] No rp1-cfe/rp1_cfe duplicate detected, nothing to do."
           fi
@@ -483,6 +523,13 @@ jobs:
           fi
           echo "[INFO] Module build CROSS_COMPILE=${MODULE_CROSS_COMPILE}"
 
+          echo "[INFO] Running 'make modules_prepare' for kernel module build ..."
+          make -C "${LINUX_SRC}" \
+            ARCH="${ARCH}" \
+            CROSS_COMPILE="${MODULE_CROSS_COMPILE}" \
+            modules_prepare \
+            2>&1 | tail -60
+
           echo "[INFO] Building base kernel modules ..."
           make -C "${LINUX_SRC}" \
             ARCH="${ARCH}" \
@@ -559,6 +606,13 @@ jobs:
           esac
           [[ -x "${MODULE_CROSS_COMPILE}gcc" ]] || MODULE_CROSS_COMPILE="${CROSS_COMPILE}"
 
+          echo "[INFO] Running 'make modules_prepare' for QUIC module build ..."
+          make -C "${LINUX_SRC}" \
+            ARCH="${ARCH}" \
+            CROSS_COMPILE="${MODULE_CROSS_COMPILE}" \
+            modules_prepare \
+            2>&1 | tail -60
+
           make -C "${LINUX_SRC}" \
             ARCH="${ARCH}" \
             KBUILD_MODPOST_WARN=1 \
@@ -593,11 +647,20 @@ jobs:
             exit 0
           fi
 
+          # Resolve Buildroot cross-compiler for ZFS build.
+          OS_DIR="${GITHUB_WORKSPACE}/operating-system"
+          case "${ARCH}" in
+            arm64) MODULE_CROSS_COMPILE="${OS_DIR}/output/host/bin/aarch64-buildroot-linux-gnu-" ;;
+            x86)   MODULE_CROSS_COMPILE="${OS_DIR}/output/host/bin/x86_64-buildroot-linux-gnu-" ;;
+            *)     MODULE_CROSS_COMPILE="${CROSS_COMPILE}" ;;
+          esac
+          [[ -x "${MODULE_CROSS_COMPILE}gcc" ]] || MODULE_CROSS_COMPILE="${CROSS_COMPILE}"
+
           # ZFS configure needs utsrelease.h from 'make prepare'.
           echo "[INFO] Running 'make prepare' for ZFS configure ..."
           make -C "${LINUX_SRC}" \
             ARCH="${ARCH}" \
-            CROSS_COMPILE="${CROSS_COMPILE}" \
+            CROSS_COMPILE="${MODULE_CROSS_COMPILE}" \
             prepare \
             2>&1 | tail -60
 
@@ -653,17 +716,16 @@ jobs:
 
           make -C "${LINUX_SRC}" \
             ARCH="${ARCH}" \
-            CROSS_COMPILE="${CROSS_COMPILE}" \
+            CROSS_COMPILE="${MODULE_CROSS_COMPILE}" \
             olddefconfig \
             2>&1 | tail -30
 
-          OS_DIR="${GITHUB_WORKSPACE}/operating-system"
-          case "${ARCH}" in
-            arm64) MODULE_CROSS_COMPILE="${OS_DIR}/output/host/bin/aarch64-buildroot-linux-gnu-" ;;
-            x86)   MODULE_CROSS_COMPILE="${OS_DIR}/output/host/bin/x86_64-buildroot-linux-gnu-" ;;
-            *)     MODULE_CROSS_COMPILE="${CROSS_COMPILE}" ;;
-          esac
-          [[ -x "${MODULE_CROSS_COMPILE}gcc" ]] || MODULE_CROSS_COMPILE="${CROSS_COMPILE}"
+          echo "[INFO] Running 'make modules_prepare' for ZFS module build ..."
+          make -C "${LINUX_SRC}" \
+            ARCH="${ARCH}" \
+            CROSS_COMPILE="${MODULE_CROSS_COMPILE}" \
+            modules_prepare \
+            2>&1 | tail -60
 
           make -C "${LINUX_SRC}" \
             ARCH="${ARCH}" \