grub: replace legacy grub install scripts

Translate old legacy grub scripts into grub.py
Implement ogGrubInstallMbr as install_main_grub() and
ogGrubInstallPartition as install_linux_grub().

Add grub configuration file generator through the classes
GrubConfig and MenuEntry.

Ensure EFI tree structure compatibility with legacy code.
The structure of the created folders in the ESP is non-standard,
efi binaries are usually located in the folder below the EFI/
directory.

Structure used by ogClient:

EFI/
├── grub/
│   └── Boot/
│       ├── BOOTX64.CSV
│       ├── grub.cfg
│       ├── mmx64.efi
│       ├── shimx64.efi
│       ├── BOOTX64.EFI
│       ├── grubx64.efi
│       └── ogloader.efi
...

The function _mangle_efi_folder handles the folder structure after
grub-install to comply with the location expected by ogLive.

install_linux_grub() installs a grub local to each Linux install
to enable chainloading, each grub is located in EFI/Part-xx-yy/ in
UEFI. The local linux BIOS grub in legacy scripts is unreliable,
grub-install reports a failure during the install process.

install_main_grub() installs a global grub in EFI/grub/ to show a
grub menu when the pxe boot fails. The global grub contains entries
to every installed os. No global grub is installed for BIOS
systems, a Boot partition would be required to store the grub
configuration.

1 files changed, 5 insertions, 31 deletions

diff --git a/src/utils/postinstall.py b/src/utils/postinstall.py
index 221da81..90b8cc6 100644
--- a/src/utils/postinstall.py
+++ b/src/utils/postinstall.py
@@ -12,6 +12,7 @@ import logging
 import hivex
 import shlex
 from src.log import OgError
+from src.utils.grub import install_main_grub, install_linux_grub
 from src.utils.bcd import update_bcd
 from src.utils.probe import *
 from src.utils.disk import *
@@ -152,19 +153,6 @@ def configure_mbr_boot_sector(disk, partition):
         logging.warning(f'{cmd_configure} returned non-zero exit status {proc.returncode}')
 
 
-def configure_grub_in_mbr(disk, partition):
-    cmd_configure = f"ogGrubInstallMbr {disk} {partition} TRUE"
-
-    proc = subprocess.run(cmd_configure,
-                          stdout=subprocess.DEVNULL,
-                          stderr=subprocess.DEVNULL,
-                          encoding='utf-8',
-                          shell=True,
-                          check=True)
-    if proc.returncode != 0:
-        logging.warning(f'{cmd_configure} returned non-zero exit status {proc.returncode}')
-
-
 def configure_fstab(disk, partition):
     logging.info(f'Configuring /etc/fstab')
     device = get_partition_device(disk, partition)
@@ -178,31 +166,17 @@ def configure_fstab(disk, partition):
     finally:
         umount(mountpoint)
 
-
-def install_grub(disk, partition):
-    cmd_configure = f"ogGrubInstallPartition {disk} {partition}"
-
-    proc = subprocess.run(cmd_configure,
-                          stdout=subprocess.DEVNULL,
-                          stderr=subprocess.DEVNULL,
-                          encoding='utf-8',
-                          shell=True,
-                          check=True)
-    if proc.returncode != 0:
-        logging.warning(f'{cmd_configure} returned non-zero exit status {proc.returncode}')
-
-
 def configure_os_linux(disk, partition):
     hostname = gethostname()
     set_linux_hostname(disk, partition, hostname)
 
     configure_fstab(disk, partition)
 
+    install_linux_grub(disk, partition)
+
     if is_uefi_supported():
         _, _, esp_part_number = get_efi_partition(disk, enforce_gpt=True)
-        configure_grub_in_mbr(disk, esp_part_number)
-
-    install_grub(disk, partition)
+        install_main_grub()
 
 
 def configure_os_windows(disk, partition):
@@ -213,7 +187,7 @@ def configure_os_windows(disk, partition):
         restore_windows_efi_bootloader(disk, partition)
 
         _, _, esp_part_number = get_efi_partition(disk, enforce_gpt=True)
-        configure_grub_in_mbr(disk, esp_part_number)
+        install_main_grub()
     else:
         configure_mbr_boot_sector(disk, partition)