Boot loader install to partion


Not sure if it is ok to start a thread, I was asking a similiar question in a older thread. How do I install the boot loader on the partition rather than the MBR? Re-installing triple boot (2003r2 ,kali, TrueOS) on a bios machine. It was working, I decided to update to a SSD and changed the sata settings in bios from legacy to native. Windows works, Kali works, TrueOS installs, on reboot the boot-loader appears and list TrueOS as F4. Press F4 a “#” is displayed on the screen press any key get a “#”, do not press any key it prints “#” all by itself (no the keyboard is not the issue). If some one can assist in getting this to work I would appreciated it. I do not care if I use TrueOS boot-loader, Grub or anything for that matter. I use to be able to use the Acronis Boot selector but it cannot find the TrueOS install. Again if I put the old Hard drive in it all works flawlessly. I do not care if it is supported or not, just want it to work.

Installing TrueOS to disk alongside dual boot of Windows/Ubuntu

windows native?

The FreeBSD bootloader still has some issues with UEFI on certain computers.

make sure “secure boot” is turned off.

Not sure past that


More info is needed.

Post this about your installed TrueOS-Disk:

$ gpart show da0
=>        40  7814037088  da0  GPT  (3.6T)
          40      409600    1  efi  (200M)
      409640        2008       - free -  (1.0M)
      411648    33554432    2  freebsd-swap  (16G)
    33966080  7780069376    3  freebsd-zfs  (3.6T)
  7814035456        1672       - free -  (836K)

Before this is known, question is unanswerable.

Other details are needed, too. But start with this.
Insert Installer-USB/DVD, and use its command line interface to show Your previously installed TrueOS-Disk.

If I had to make a wild guess, I’d think it would be possible to start TrueOS via Linux-GrUB chainloading, but to be sure about that, info about Your configuration is missing.


here it is


This 2nd one is from the tri-boot that worked with the bigger drive.


Thanks for the screen photos.

If I understand this correctly, You installed TrueOS on a non-ZFS filesystem (UFS/UFS2/FFS). Am I right? Please, confirm.

If I understand Your original post correctly, presently You can boot into none of Your 3 operating systems. Is this correct?

If You can’t boot into any of Your operating systems,
You should try to rewrite the Master Boot Record of ada0.

I would try this with all of Your operating systems while booting Your hardware from their rescue-ers/install-ers, one after the other. The order of doing this I recommend would be: TrueOS, Linux, Windows.

Let’s start with TrueOS:
TrueOS booting consists of three stages on MBR-disks.
Those are (re-)installable/initializable with:
“gpart bootcode …”.

Please, read “man gpart” and look for “boot” in there.

Afterwards, boot from installer, make sure Your root-filesytem from ada0 gets mounted somewhere, then do a change-root to this mountpoint. Afterwards enter “mount -a”. Now You can reinstall Your bootstrapping code again, using the software from Your ada0-TrueOS.

Your root filesystem is presumably “ada0s4a”.

Afterwards, reboot and check.

The same technique can be used with Linux to re-install GrUB, if necessary.


Another thing You could try:

Boot any Linux-Installer, and try to chainload the first sector of the TrueOS-partition via GrUB command line. Maybe it will work.
Personally, I never tried it as yet. But it may be the quickest solution if it works to get Your installed TrueOS running. Don’t know. Try it.


Shouldn’t the FreeBSD-partition be the “active” one, instead of the “NTFS”-partition?

I don’t know if TrueOS/FreeBSD doesn’t care about this, but normally this would be necessary, because the BIOS-firmware requires it for MBR-disk boot-partitions.

Problem is, last time I worked with BIOS/MBR Hardware was over 7 years ago. Since then I only used BIOS/MBR in Virtual Machines, and only if unavoidable. Since then, I only used GPT-partitioned disks, and no MBR-partitioned ones.

Edit: Addition
In “man gpart” we find:

The Master Boot Record (MBR) uses a 512-byte bootstrap code image, embed-
ded into the partition table’s metadata area. There are two variants of
this bootstrap code: /boot/mbr and /boot/boot0. /boot/mbr searches for a
partition with the active attribute (see the ATTRIBUTES section) in the
partition table. Then it runs next bootstrap stage. The /boot/boot0
image contains a boot manager with some additional interactive functions
for multi-booting from a user-selected partition.

Therfore, a clumsy solution could be:

Replace “boot0” by “mbr”. And change Your boot-target by setting the “active”-attribute of the OS-partition You want to boot into.

And I repeat: It’s clumsy. But according to man page, it should work.


Thank you for your help, I haven’t been able to get back to it, my dog had puppies yesterday morning and it has taken all my time. I will get back to it on Tuesday. Thanks again.


Maybe this helps, too:

EDIT: Information regarding BIOS/MBR/GRUB is scattered all around… Maybe this post will be useful if you really need to restamp TrueOSs GRUB after installing other OSes: