[OE-core] [PATCH v2 1/2] wic/plugins: Source that support both EFI and BIOS
William Bourque
wbourque at gmail.com
Fri Jul 12 14:00:19 UTC 2019
Add a source plugin that support both EFI and legacy PC-Bios.
While using this plugin, both bootloaders configurations reside
in the same /boot partitions.
This plugin has very little code : to avoid code duplication,
we simply re-import bootimg-pcbios and bootmg-efi source and
call both their SourcePlugin methods.
Signed-off-by: William Bourque <wbourque at gmail.com>
---
.../wic/plugins/source/bootimg-biosplusefi.py | 213 ++++++++++++++++++
1 file changed, 213 insertions(+)
create mode 100644 scripts/lib/wic/plugins/source/bootimg-biosplusefi.py
diff --git a/scripts/lib/wic/plugins/source/bootimg-biosplusefi.py b/scripts/lib/wic/plugins/source/bootimg-biosplusefi.py
new file mode 100644
index 0000000000..5bd7390680
--- /dev/null
+++ b/scripts/lib/wic/plugins/source/bootimg-biosplusefi.py
@@ -0,0 +1,213 @@
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# DESCRIPTION
+# This implements the 'bootimg-biosplusefi' source plugin class for 'wic'
+#
+# AUTHORS
+# William Bourque <wbourque [at) gmail.com>
+
+import types
+
+from wic.pluginbase import SourcePlugin
+from importlib.machinery import SourceFileLoader
+
+class BootimgBiosPlusEFIPlugin(SourcePlugin):
+ """
+ Create MBR + EFI boot partition
+
+ This plugin creates a boot partition that contains both
+ legacy BIOS and EFI content. It will be able to boot from both.
+ This is useful when managing PC fleet with some older machines
+ without EFI support.
+
+ Note it is possible to create an image that can boot from both
+ legacy BIOS and EFI by defining two partitions : one with arg
+ --source bootimg-efi and another one with --source bootimg-pcbios.
+ However, this method has the obvious downside that it requires TWO
+ partitions to be created on the storage device.
+ Both partitions will also be marked as "bootable" which does not work on
+ most BIOS, has BIOS often uses the "bootable" flag to determine
+ what to boot. If you have such a BIOS, you need to manually remove the
+ "bootable" flag from the EFI partition for the drive to be bootable.
+ Having two partitions also seems to confuse wic : the content of
+ the first partition will be duplicated into the second, even though it
+ will not be used at all.
+
+ Also, unlike "isoimage-isohybrid" that also does BIOS and EFI, this plugin
+ allows you to have more than only a single rootfs partitions and does
+ not turn the rootfs into an initramfs RAM image.
+
+ This plugin is made to put everything into a single /boot partition so it
+ does not have the limitations listed above.
+
+ The plugin is made so it does tries not to reimplement what's already
+ been done in other plugins; as such it imports "bootimg-pcbios"
+ and "bootimg-efi".
+ Plugin "bootimg-pcbios" is used to generate legacy BIOS boot.
+ Plugin "bootimg-efi" is used to generate the UEFI boot. Note that it
+ requires a --sourceparams argument to know which loader to use; refer
+ to "bootimg-efi" code/documentation for the list of loader.
+
+ Imports are handled with "SourceFileLoader" from importlib as it is
+ otherwise very difficult to import module that has hyphen "-" in their
+ filename.
+ The SourcePlugin() methods used in the plugins (do_install_disk,
+ do_configure_partition, do_prepare_partition) are then called on both,
+ beginning by "bootimg-efi".
+
+ Plugin options, such as "--sourceparams" can still be passed to a
+ plugin, as long they does not cause issue in the other plugin.
+
+ Example wic configuration:
+ part /boot --source bootimg-biosplusefi --sourceparams="loader=grub-efi"\\
+ --ondisk sda --label os_boot --active --align 1024 --use-uuid
+ """
+
+ name = 'bootimg-biosplusefi'
+
+ __PCBIOS_MODULE_NAME = "bootimg-pcbios"
+ __EFI_MODULE_NAME = "bootimg-efi"
+
+ __imgEFIObj = None
+ __imgBiosObj = None
+
+ @classmethod
+ def __init__(cls):
+ """
+ Constructor (init)
+ """
+
+ # XXX
+ # For some reasons, __init__ constructor is never called.
+ # Something to do with how pluginbase works?
+ cls.__instanciateSubClasses()
+
+ @classmethod
+ def __instanciateSubClasses(cls):
+ """
+
+ """
+
+ # Import bootimg-pcbios (class name "BootimgPcbiosPlugin")
+ modulePath = os.path.join(os.path.dirname(os.path.realpath(__file__)),
+ cls.__PCBIOS_MODULE_NAME + ".py")
+ loader = SourceFileLoader(cls.__PCBIOS_MODULE_NAME, modulePath)
+ mod = types.ModuleType(loader.name)
+ loader.exec_module(mod)
+ cls.__imgBiosObj = mod.BootimgPcbiosPlugin()
+
+ # Import bootimg-efi (class name "BootimgEFIPlugin")
+ modulePath = os.path.join(os.path.dirname(os.path.realpath(__file__)),
+ cls.__EFI_MODULE_NAME + ".py")
+ loader = SourceFileLoader(cls.__EFI_MODULE_NAME, modulePath)
+ mod = types.ModuleType(loader.name)
+ loader.exec_module(mod)
+ cls.__imgEFIObj = mod.BootimgEFIPlugin()
+
+ @classmethod
+ def do_install_disk(cls, disk, disk_name, creator, workdir, oe_builddir,
+ bootimg_dir, kernel_dir, native_sysroot):
+ """
+ Called after all partitions have been prepared and assembled into a
+ disk image.
+ """
+
+ if ( (not cls.__imgEFIObj) or (not cls.__imgBiosObj) ):
+ cls.__instanciateSubClasses()
+
+ cls.__imgEFIObj.do_install_disk(
+ disk,
+ disk_name,
+ creator,
+ workdir,
+ oe_builddir,
+ bootimg_dir,
+ kernel_dir,
+ native_sysroot)
+
+ cls.__imgBiosObj.do_install_disk(
+ disk,
+ disk_name,
+ creator,
+ workdir,
+ oe_builddir,
+ bootimg_dir,
+ kernel_dir,
+ native_sysroot)
+
+ @classmethod
+ def do_configure_partition(cls, part, source_params, creator, cr_workdir,
+ oe_builddir, bootimg_dir, kernel_dir,
+ native_sysroot):
+ """
+ Called before do_prepare_partition()
+ """
+
+ if ( (not cls.__imgEFIObj) or (not cls.__imgBiosObj) ):
+ cls.__instanciateSubClasses()
+
+ cls.__imgEFIObj.do_configure_partition(
+ part,
+ source_params,
+ creator,
+ cr_workdir,
+ oe_builddir,
+ bootimg_dir,
+ kernel_dir,
+ native_sysroot)
+
+ cls.__imgBiosObj.do_configure_partition(
+ part,
+ source_params,
+ creator,
+ cr_workdir,
+ oe_builddir,
+ bootimg_dir,
+ kernel_dir,
+ native_sysroot)
+
+ @classmethod
+ def do_prepare_partition(cls, part, source_params, creator, cr_workdir,
+ oe_builddir, bootimg_dir, kernel_dir,
+ rootfs_dir, native_sysroot):
+ """
+ Called to do the actual content population for a partition i.e. it
+ 'prepares' the partition to be incorporated into the image.
+ """
+
+ if ( (not cls.__imgEFIObj) or (not cls.__imgBiosObj) ):
+ cls.__instanciateSubClasses()
+
+ cls.__imgEFIObj.do_prepare_partition(
+ part,
+ source_params,
+ creator,
+ cr_workdir,
+ oe_builddir,
+ bootimg_dir,
+ kernel_dir,
+ rootfs_dir,
+ native_sysroot)
+
+ cls.__imgBiosObj.do_prepare_partition(
+ part,
+ source_params,
+ creator,
+ cr_workdir,
+ oe_builddir,
+ bootimg_dir,
+ kernel_dir,
+ rootfs_dir,
+ native_sysroot)
--
2.17.1
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