wic: add support for bootable pcbios partition with Xen hypervisor

New bootimg-biosxen wic plugin to populate a boot partition for
launching Xen and dom0.

Includes example kickstart wks files to generate disk images to boot
into Xen from PC BIOS.

  eg: wic create directdisk-xen -e xen-image-minimal

and write the resulting image file to a disk for boot.

Signed-off-by: Christopher Clark <christopher.clark6@baesystems.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

1 files changed, 212 insertions, 0 deletions

diff --git a/scripts/lib/wic/plugins/source/bootimg-biosxen.py b/scripts/lib/wic/plugins/source/bootimg-biosxen.py
new file mode 100644
index 00000000..f00747db
--- /dev/null
+++ b/scripts/lib/wic/plugins/source/bootimg-biosxen.py
@@ -0,0 +1,212 @@
+#
+# 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-biosxen' source plugin class for 'wic'
+#
+# Bootloader arguments: Xen args are separated from Linux ones at '---':
+# eg.
+#   bootloader --append="console=com1,vga com1=115200,8n1 --- console=hvc0"
+#
+# Optional source param: initrd
+# accepts multiple ramdisk files to be supplied to multiboot.
+#  eg.
+#   part /boot --source bootimg-biosxen --sourceparams="initrd=foo.initrd;bar.initrd"
+#
+# AUTHORS
+# Christopher Clark <christopher.w.clark [at] gmail.com>
+# Elements derived from bootimg-biosplusefi.py by:
+#   William Bourque <wbourque [at] gmail.com>
+
+import logging
+import os
+import types
+
+from wic import WicError
+import wic.pluginbase
+from importlib.machinery import SourceFileLoader
+from wic.misc import (exec_cmd, get_bitbake_var)
+
+logger = logging.getLogger('wic')
+
+class BootimgBiosXenPlugin(wic.pluginbase.SourcePlugin):
+    """
+    Create MBR boot partition including files for Xen
+
+    """
+
+    name = 'bootimg-biosxen'
+    __PCBIOS_MODULE_NAME = "bootimg-pcbios"
+    __imgBiosObj = None
+
+    @classmethod
+    def __init__(cls):
+        """
+        Constructor (init)
+        """
+        # original comment from bootimg-biosplusefi.py :
+        # "XXX For some reasons, __init__ constructor is never called.
+        #  Something to do with how pluginbase works?"
+        cls.__instanciateBIOSClass()
+
+    @classmethod
+    def __instanciateBIOSClass(cls):
+        """
+
+        """
+        # Import bootimg-pcbios (class name "BootimgPcbiosPlugin")
+        modulePath = os.path.join(os.path.dirname(wic.pluginbase.__file__),
+                                  "plugins", "source",
+                                  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()
+
+    @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.__imgBiosObj:
+            cls.__instanciateBIOSClass()
+
+        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(), creates syslinux config
+        """
+        if not cls.__imgBiosObj:
+            cls.__instanciateBIOSClass()
+
+        bootloader = creator.ks.bootloader
+
+        if not bootloader.configfile:
+            splash = os.path.join(cr_workdir, "/hdd/boot/splash.jpg")
+            if os.path.exists(splash):
+                splashline = "menu background splash.jpg"
+            else:
+                splashline = ""
+
+            syslinux_conf = ""
+            syslinux_conf += "PROMPT 0\n"
+            syslinux_conf += "TIMEOUT " + str(bootloader.timeout) + "\n"
+            syslinux_conf += "\n"
+            syslinux_conf += "ALLOWOPTIONS 1\n"
+            syslinux_conf += "\n"
+            if splashline:
+                syslinux_conf += "%s\n" % splashline
+
+            syslinux_conf += "DEFAULT boot\n"
+            syslinux_conf += "LABEL boot\n"
+            syslinux_conf += "  KERNEL mboot.c32\n"
+
+            # Split the bootloader args at '---' to separate the Xen args
+            # from the Linux kernel args.
+            # The Xen args here are defaults; overridden by bootloader append.
+            xen_args = "console=com1,vga com1=115200,8n1"
+            kernel_append = ""
+            if bootloader.append:
+                separator_pos = bootloader.append.find('---')
+                if separator_pos != -1:
+                    xen_args = bootloader.append[:separator_pos]
+                    kernel_append = bootloader.append[separator_pos+3:]
+                else:
+                    kernel_append = bootloader.append
+
+            kernel_args = "label=boot root=%s %s" % \
+                          (creator.rootdev, kernel_append)
+
+            syslinux_conf += "  APPEND /xen.gz %s --- /vmlinuz %s" % \
+                             (xen_args, kernel_args)
+
+            initrd = source_params.get('initrd')
+            if initrd:
+                initrds = initrd.split(';')
+                for initrd_file in initrds:
+                    syslinux_conf += " --- /%s" % os.path.basename(initrd_file)
+            syslinux_conf += "\n"
+
+            logger.debug("Writing syslinux config %s/hdd/boot/syslinux.cfg",
+                         cr_workdir)
+
+            hdddir = "%s/hdd/boot" % cr_workdir
+            install_cmd = "install -d %s" % hdddir
+            exec_cmd(install_cmd)
+
+            cfg = open("%s/hdd/boot/syslinux.cfg" % cr_workdir, "w")
+            cfg.write(syslinux_conf)
+            cfg.close()
+
+        else:
+            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.__imgBiosObj:
+            cls.__instanciateBIOSClass()
+
+        bootimg_dir = cls.__imgBiosObj._get_bootimg_dir(bootimg_dir, 'syslinux')
+        hdddir = "%s/hdd/boot" % cr_workdir
+
+        # machine-deduction logic originally from isoimage-isohybrid.py
+        initrd_dir = get_bitbake_var("DEPLOY_DIR_IMAGE")
+        if not initrd_dir:
+            raise WicError("Couldn't find DEPLOY_DIR_IMAGE, exiting.")
+        machine = os.path.basename(initrd_dir)
+
+        xen = "xen-" + machine + ".gz"
+
+        cmds = ["install -m 0644 %s/%s %s/xen.gz" %
+                (kernel_dir, xen, hdddir),
+                "install -m 0644 %s/syslinux/mboot.c32 %s/mboot.c32" %
+                (bootimg_dir, hdddir)]
+
+        initrd = source_params.get('initrd')
+
+        # Allow multiple 'initrds', as per the bootimg-efi class.
+        # This can be used to install additional binaries for multiboot.
+        # eg. TXT ACMs, XSM/Flask policy file, microcode binary
+        if initrd:
+            initrds = initrd.split(';')
+            for initrd_file in initrds:
+                cmds.append("install -m 0644 %s/%s %s/%s" %
+                            (kernel_dir, initrd_file, hdddir,
+                             os.path.basename(initrd_file)))
+
+        for install_cmd in cmds:
+            exec_cmd(install_cmd)
+
+        cls.__imgBiosObj.do_prepare_partition(part, source_params,
+                                              creator, cr_workdir,
+                                              oe_builddir, bootimg_dir,
+                                              kernel_dir, rootfs_dir,
+                                              native_sysroot)