diff options
Diffstat (limited to 'morphlib/writeexts.py')
| -rw-r--r-- | morphlib/writeexts.py | 62 |
1 files changed, 54 insertions, 8 deletions
diff --git a/morphlib/writeexts.py b/morphlib/writeexts.py index b4912db1..334dc15c 100644 --- a/morphlib/writeexts.py +++ b/morphlib/writeexts.py @@ -120,7 +120,8 @@ class WriteExtension(cliapp.Application): raise try: self.create_btrfs_system_layout( - temp_root, mp, version_label='factory') + temp_root, mp, version_label='factory', + disk_uuid=self.get_uuid(raw_disk)) except BaseException, e: sys.stderr.write('Error creating Btrfs system layout') self.unmount(mp) @@ -186,6 +187,13 @@ class WriteExtension(cliapp.Application): '''Create a btrfs filesystem on the disk.''' self.status(msg='Creating btrfs filesystem') cliapp.runcmd(['mkfs.btrfs', '-L', 'baserock', location]) + + def get_uuid(self, location): + '''Get the UUID of a block device's file system.''' + # Requires util-linux blkid; busybox one ignores options and + # lies by exiting successfully. + return cliapp.runcmd(['blkid', '-s', 'UUID', '-o', 'value', + location]).strip() def mount(self, location): '''Mount the filesystem so it can be tweaked. @@ -212,10 +220,12 @@ class WriteExtension(cliapp.Application): cliapp.runcmd(['umount', mount_point]) os.rmdir(mount_point) - def create_btrfs_system_layout(self, temp_root, mountpoint, version_label): + def create_btrfs_system_layout(self, temp_root, mountpoint, version_label, + disk_uuid=None): '''Separate base OS versions from state using subvolumes. ''' + initramfs = self.find_initramfs(temp_root) version_root = os.path.join(mountpoint, 'systems', version_label) state_root = os.path.join(mountpoint, 'state') @@ -238,7 +248,12 @@ class WriteExtension(cliapp.Application): if self.bootloader_is_wanted(): self.install_kernel(version_root, temp_root) self.install_syslinux_menu(mountpoint, version_root) - self.install_extlinux(mountpoint) + if initramfs is not None: + self.install_initramfs(initramfs, version_root) + self.install_extlinux(mountpoint, disk_uuid) + else: + self.install_extlinux(mountpoint) + def create_orig(self, version_root, temp_root): '''Create the default "factory" system.''' @@ -322,6 +337,29 @@ class WriteExtension(cliapp.Application): fstab.write() return state_dirs_to_create + def find_initramfs(self, temp_root): + '''Check whether the rootfs has an initramfs. + + Uses the INITRAMFS_PATH option to locate it. + ''' + if 'INITRAMFS_PATH' in os.environ: + initramfs = os.path.join(temp_root, os.environ['INITRAMFS_PATH']) + if not os.path.exists(initramfs): + raise morphlib.Error('INITRAMFS_PATH specified, ' + 'but file does not exist') + return initramfs + return None + + def install_initramfs(self, initramfs_path, version_root): + '''Install the initramfs outside of 'orig' or 'run' subvolumes. + + This is required because syslinux doesn't traverse subvolumes when + loading the kernel or initramfs. + ''' + self.status(msg='Installing initramfs') + initramfs_dest = os.path.join(version_root, 'initramfs') + cliapp.runcmd(['cp', '-a', initramfs_path, initramfs_dest]) + def install_kernel(self, version_root, temp_root): '''Install the kernel outside of 'orig' or 'run' subvolumes''' @@ -337,20 +375,28 @@ class WriteExtension(cliapp.Application): def get_extra_kernel_args(self): return os.environ.get('KERNEL_ARGS', '') - def install_extlinux(self, real_root): + def install_extlinux(self, real_root, disk_uuid=None): '''Install extlinux on the newly created disk image.''' self.status(msg='Creating extlinux.conf') config = os.path.join(real_root, 'extlinux.conf') - kernel_args = self.get_extra_kernel_args() + kernel_args = ( + 'rw ' # ro ought to work, but we don't test that regularly + 'init=/sbin/init ' # default, but it doesn't hurt to be explicit + 'rootfstype=btrfs ' # required when using initramfs, also boots + # faster when specified without initramfs + 'rootflags=subvol=systems/default/run ') # boot runtime subvol + kernel_args += 'root=%s ' % ('/dev/sda' if disk_uuid is None + else 'UUID=%s' % disk_uuid) + kernel_args += self.get_extra_kernel_args() with open(config, 'w') as f: f.write('default linux\n') f.write('timeout 1\n') f.write('label linux\n') f.write('kernel /systems/default/kernel\n') - f.write('append root=/dev/sda ' - 'rootflags=subvol=systems/default/run ' - '%s init=/sbin/init rw\n' % (kernel_args)) + if disk_uuid is not None: + f.write('initrd /systems/default/initramfs\n') + f.write('append %s\n' % kernel_args) self.status(msg='Installing extlinux') cliapp.runcmd(['extlinux', '--install', real_root]) |