-2

How to configure to boot Ubuntu with legacy BIOS and GPT, without to need to install Grub, LILO, UEFI or other additional bootmanager in extra partition or on ubuntu partition? Or does the GPT no more able to point to a boot partition like MBR?

No other additional OS like p.e. a 2nd Linux or a windows are installed.

The follow configuration don't work:

  • PC CMOS configuration set to legacy BIOS, not to UEFI
  • Use MBR not GPT on hard disk
  • Ubuntu partition set by GParted to "legacy_boot"

The follow, not question fitting configuration, works fine (without to need LiLo, Grub2 or UEFI) :

  • PC CMOS configuration set to legacy BIOS, not to UEFI
  • Use MBR not GPT on hard disk
  • Ubuntu partition set by GParted to "boot"
Alfred.37
  • 79
  • 2
    Only Ubuntu and official flavors of Ubuntu (https://ubuntu.com/download/flavours) are on-topic here, refer to https://askubuntu.com/help/on-topic where you'll find other SE sites where you question will be welcome if you don't want to use a Linux Mint forum. (One advantage of Ubuntu is it's many support options, you opted for Linux Mint so take advantage of it's support options, or SE Unix & Linux) – guiverc Oct 04 '22 at 10:29
  • 1
    THX. I fixed it now. – Alfred.37 Oct 04 '22 at 10:31
  • Install LILO? >:-) You always need a boot loader when using Ubuntu. – Rinzwind Oct 04 '22 at 10:43
  • I updated the question. THX for the remarks questions. – Alfred.37 Oct 05 '22 at 10:00
  • If you don't want lilo, grub or any of the pre-packaged solutions (where lilo and grub were the best!); you'll have to create your own. I consider the GRUB stage 0 (MBR) as just a pointer anyway (yeah it's also the very limited grub rescue) so code your own alternative. Ubuntu replaced the older alternatives with the GNU default boot loader (ie. grub) as has more powerful dual boot & recovery options than the various alternatives. – guiverc Oct 05 '22 at 10:24

2 Answers2

3

AFAIK, you can't. Your BIOS goes to the first sector of your hard disk (MBR) to see where to boot. In the MBR, it finds a link to a bootloader (in the case of Ubuntu it's GRUB) and the bootloader continues the booting sequence. If needed you get a menu which allows you to choose which OS/kernel to boot and then it boots the OS. If there is only one OS, the GRUB just boots that.

If you try to boot without GRUB, the MBR says there is no bootloader so the BIOS skips that hard disk in the boot order list and since you don't have any other OS, the BIOS says "No OS detected" (or something similar)

Oh jea UEFI is not a bootloader, it's firmware and should be considerd to be the same level as the BIOS, although it works on partition level using GPT instead of the bios working on physical level using MBR. BIOS (and I think also CSM) can still function using GPT although it only reads the first sector so it just detects an MBR. You cannot have GPT without MBR

Irsu85
  • 551
0

You can install, not all, a some sorts of bootloaders on MBR also (only one at the same time ...). Don`t need a additional partition in all cases?

For Ubuntu see the follow:

Set the bootable flag for your ubuntu partition, p.e. by GPartetd

sudo grub-install --boot-directory=/boot /dev/sda


sudo update-grub

Source:

https://www.xmodulo.com/install-grub-bootloader-master-boot-record-ubuntu-mint.html

Backup of source:

https://web.archive.org/web/20221006094835/https://www.xmodulo.com/install-grub-bootloader-master-boot-record-ubuntu-mint.html

For additional information check the follow:

Source: Where is the boot loader installed?

Backup of source:

https://web.archive.org/web/20221006095700/https://askubuntu.com/questions/142912/where-is-the-boot-loader-installed

The follow list show you possible locations of installation of a lot of different bootloaders.

"The column MBR (Master Boot Record) refers to whether or not the boot loader can be stored in the first sector of a mass storage device. The column VBR (Volume Boot Record) refers to the ability of the boot loader to be stored in the first sector of any partition on a mass storage device."

Source:

https://en.wikipedia.org/wiki/Comparison_of_bootloaders#Storage_medium_support

Backup of source:

https://web.archive.org/web/20221006103618/https://en.wikipedia.org/wiki/Comparison_of_bootloaders

Alfred.37
  • 79