Install recovery kernel directly to image, not to build dir.

The recovery kernel is different from the regular kernel, and
should be kept sandboxed so that it does not mess with our
build directory.

We also need to give the recovery kernel a different PKGDIR so
that it does not overwrite our prebuilts for the ordinary
kernel.

BUG=chromium-os:18691
TEST=build_image --factory_install, mod_image_for_recovery.sh

Change-Id: I678a94305d5f30bc2c95bf4e53cfe81b2ae9d8ef
Reviewed-on: http://gerrit.chromium.org/gerrit/5305
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: David James <davidjames@chromium.org>

build_image

@@ -240,13 +240,6 @@ emerge_to_image() {
 # Check that the build root is sane.
 "${BUILD_LIBRARY_DIR}/test_build_root" --root="${BOARD_ROOT}"
 
-# Freshen kernel with correct USE flags. This is a noop if we have
-# the right kernel prebuilt. Factory install uses USE="initramfs".
-# We don't allow building from source with the image as a target,
-# and it's not possible to store prebuilts for the same package
-# with different use flags.
-sudo -E ${EMERGE_BOARD_CMD} -uDNv -g virtual/kernel
-
 # Use canonical path since some tools (e.g. mount) do not like symlinks.
 # Append build attempt to output directory.
 IMAGE_SUBDIR="${CHROMEOS_VERSION_STRING}-a${FLAGS_build_attempt}"
@@ -638,6 +631,12 @@ create_base_image() {
     copy_gcc_libs "${ROOT_FS_DIR}" $atom
   done
 
+  if [ ${FLAGS_factory_install} -eq ${FLAGS_TRUE} ]; then
+    # Install our custom factory install kernel with the appropriate use flags
+    # to the image.
+    emerge_custom_kernel "${ROOT_FS_DIR}"
+  fi
+
   # We "emerge --root=${ROOT_FS_DIR} --root-deps=rdeps --usepkgonly" all of the
   # runtime packages for chrome os. This builds up a chrome os image from
   # binary packages with runtime dependencies only.  We use INSTALL_MASK to

common.sh

@@ -687,3 +687,39 @@ function find_coreboot_component () {
   local override=$2
   find_fw_component "firmware coreboot" "${component}" "${override}"
 }
+
+function emerge_custom_kernel() {
+  local install_root="$1"
+  local root=${FLAGS_build_root}/${FLAGS_board}
+  local tmp_pkgdir=${root}/custom-packages
+
+  # Clean up any leftover state in custom directories.
+  sudo rm -rf ${tmp_pkgdir}
+
+  # Update chromeos-initramfs to contain the latest binaries from the build
+  # tree. This is basically just packaging up already-built binaries from
+  # $root. We are careful not to muck with the existing prebuilts so that
+  # prebuilts can be uploaded in parallel.
+  # TODO(davidjames): Implement ABI deps so that chromeos-initramfs will be
+  # rebuilt automatically when its dependencies change.
+  sudo -E PKGDIR=${tmp_pkgdir} $EMERGE_BOARD_CMD -1 \
+    chromeos-base/chromeos-initramfs || die "Cannot emerge chromeos-initramfs"
+
+  # Verify all dependencies of the kernel are installed. This should be a
+  # no-op, but it's good to check in case a developer didn't run
+  # build_packages.
+  local kernel=$(portageq-${FLAGS_board} expand_virtual ${root} virtual/kernel)
+  sudo -E PKGDIR=${tmp_pkgdir} $EMERGE_BOARD_CMD --onlydeps \
+    ${kernel} || die "Cannot emerge kernel dependencies"
+
+  # Build the kernel. This uses the standard root so that we can pick up the
+  # initramfs from there. But we don't actually install the kernel to the
+  # standard root, because that'll muck up the kernel debug symbols there,
+  # which we want to upload in parallel.
+  sudo -E PKGDIR=${tmp_pkgdir} $EMERGE_BOARD_CMD --buildpkgonly \
+    ${kernel} || die "Cannot emerge kernel"
+
+  # Install the custom kernel to the provided install root.
+  sudo -E PKGDIR=${tmp_pkgdir} $EMERGE_BOARD_CMD --usepkgonly \
+    --root=${install_root} ${kernel} || die "Cannot emerge kernel to root"
+}

mod_image_for_recovery.sh

@@ -148,20 +148,8 @@ BOAT
   die "$* failed"
 }
 
-emerge_recovery_kernel() {
-  echo "Emerging custom recovery initramfs and kernel"
-  local emerge_flags="-uDNv1 --usepkg=n --selective=n"
-
-  $EMERGE_BOARD_CMD \
-    $emerge_flags --binpkg-respect-use=y \
-    chromeos-initramfs || failboat "emerge initramfs"
-  USE="fbconsole initramfs" $EMERGE_BOARD_CMD \
-                    $emerge_flags --binpkg-respect-use=y \
-                    virtual/kernel || failboat "emerge kernel"
-}
-
 create_recovery_kernel_image() {
-  local sysroot="${FLAGS_build_root}/${FLAGS_board}"
+  local sysroot="$FACTORY_ROOT"
   local vmlinuz="$sysroot/boot/vmlinuz"
   local root_offset=$(partoffset "$FLAGS_image" 3)
   local root_size=$(partsize "$FLAGS_image" 3)
@@ -288,8 +276,9 @@ install_recovery_kernel() {
   sudo $GPT add -i 2 -S 1 "$RECOVERY_IMAGE"
 
   # Repeat for the legacy bioses.
-  # Replace vmlinuz.A with the recovery version
-  local sysroot="${FLAGS_build_root}/${FLAGS_board}"
+  # Replace vmlinuz.A with the recovery version we built.
+  # TODO(wad): Extract the $RECOVERY_KERNEL_IMAGE and grab vmlinuz from there.
+  local sysroot="$FACTORY_ROOT"
   local vmlinuz="$sysroot/boot/vmlinuz"
   local failed=0
 
@@ -441,8 +430,12 @@ if [ -z "$INSTALL_VBLOCK" ]; then
   die "Could not copy the vblock from stateful."
 fi
 
+# Build the recovery kernel.
+FACTORY_ROOT="${FLAGS_build_root}/${FLAGS_board}/factory-root"
+USE="fbconsole initramfs" emerge_custom_kernel "$FACTORY_ROOT" \
+  || failboat "Cannot emerge custom kernel"
+
 if [ -z "$FLAGS_kernel_image" ]; then
-  emerge_recovery_kernel
   create_recovery_kernel_image
   echo "Recovery kernel created at $RECOVERY_KERNEL_IMAGE"
 else