[PATCH v3 2/3] linux: leverage dpkg_prepare to install build dependencies

[Cedric Hombourger <Cedric_Hombourger@mentor.com>]

To prepare removal of flock calls around dpkg/apt operations, move
the code installing build dependencies to dpkg_prepare()

Signed-off-by: Cedric Hombourger <Cedric_Hombourger@mentor.com>
---
 meta/recipes-kernel/linux/files/build-kernel.sh | 5 -----
 meta/recipes-kernel/linux/linux-custom.inc      | 8 ++++++++
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/meta/recipes-kernel/linux/files/build-kernel.sh b/meta/recipes-kernel/linux/files/build-kernel.sh
index 8b58e93..498067c 100644
--- a/meta/recipes-kernel/linux/files/build-kernel.sh
+++ b/meta/recipes-kernel/linux/files/build-kernel.sh
@@ -33,11 +33,6 @@ REPACK_DIR="$1/../repack"
 REPACK_LINUX_IMAGE_DIR="${REPACK_DIR}/linux-image"
 REPACK_LINUX_HEADERS_DIR="${REPACK_DIR}/linux-headers"
 
-# Lock-protected because apt and dpkg do not wait in case of contention
-flock /dpkg.lock \
-    apt-get install -y -o Debug::pkgProblemResolver=yes \
-        --no-install-recommends ${KBUILD_DEPENDS}
-
 cd $1
 make olddefconfig
 
diff --git a/meta/recipes-kernel/linux/linux-custom.inc b/meta/recipes-kernel/linux/linux-custom.inc
index 87d4377..26c6ad8 100644
--- a/meta/recipes-kernel/linux/linux-custom.inc
+++ b/meta/recipes-kernel/linux/linux-custom.inc
@@ -28,6 +28,14 @@ KBUILD_DEPENDS ?= "libssl-dev libelf-dev bc"
 KERNEL_DEBIAN_DEPENDS ?= "initramfs-tools | linux-initramfs-tool, kmod, linux-base (>= 4.3~)"
 KERNEL_HEADERS_DEBIAN_DEPENDS ?= "libc6, libssl1.1"
 
+dpkg_prepare() {
+	# Lock-protected because apt and dpkg do not wait in case of contention
+	sudo -E chroot ${BUILDCHROOT_DIR} \
+		flock /dpkg.lock apt-get install \
+			-y -o Debug::pkgProblemResolver=yes \
+			--no-install-recommends ${KBUILD_DEPENDS}
+}
+
 dpkg_runbuild() {
 	# Install package builder script
 	sudo install -m 755 ${WORKDIR}/build-kernel.sh ${BUILDCHROOT_DIR}
-- 
2.11.0