BOOTMGR is missing

B

balanga

Is there any way to fix a BOOTMGR is missing by booting up FreeBSD and accessing the Windows partition using ntfs-3g, or maybe installing a FreeBSD boot manager.
 
We cannot answer this as we don't know your particular system.
Do you boot MBR
Do you UEFI
Do you press a key on booting to check boot device.
Do you have a separate boot partition.
Where is your /boot directory located on which partition & filesystem.
Where is you "boot0/boot1" located.

Note,

In the traditional FreeBSD BIOS/Legacy boot process, the bootstrap is divided into multiple stages due to the strict space limitations of the Master Boot Record (MBR) and partition boot sectors.

Stage 0: boot0 (The Boot Manager)
  • Location: Resides in the first 512 bytes of the disk, known as the Master Boot Record (MBR).
  • Function: It is a small program (limited to 446 bytes of code) that scans the partition table to find a bootable slice.
  • Interaction: If multiple operating systems are present, boot0 provides a simple menu (e.g., F1 Win, F2 FreeBSD) allowing you to select which partition to boot from.
  • Next Step: Once a FreeBSD slice is selected, boot0 executes the code in the first sector of that slice, which is boot1.
Stage 1: boot1 (The Slice Boot Sector)
  • Location: Found in the first 512-byte sector of the specific FreeBSD partition (slice).
  • Function: Extremely basic because of its 512-byte size limit. Its primary job is to understand the FreeBSD bsdlabel to locate and load the more complex boot2.
  • Next Step: It loads boot2 into memory and jumps to it.
Stage 2: boot2 (The Loader Interface)
  • Location: Usually concatenated with boot1 on the disk but logically separate; it resides in the first 16 sectors of the FreeBSD slice.
  • Function: More sophisticated than boot1, it contains a small driver for the UFS file system, allowing it to find and read files from the disk.
  • Interaction: If the boot process is interrupted here, it provides a prompt (e.g., >> FreeBSD/i386 BOOT) where you can manually specify a kernel or loader to run.
  • Next Step: By default, its main task is to find and execute the loader, which is the final interactive stage before the kernel starts.
Summary of Boot Flow
Stage
File NamePrimary Task
Stage 0boot0Selects which disk partition to boot from (MBR).
Stage 1boot1Locates and loads boot2 from the slice.
Stage 2boot2Locates and loads the loader file from the UFS partition.
Stage 3loaderFinal stage that loads the FreeBSD Kernel.
Note: In modern UEFI systems, this multi-stage assembly process is replaced by a single EFI executable (/boot/boot1.efi or loader.efi) that the firmware loads directly.
 
Note,

To install
boot0 and boot1 in FreeBSD (typically on systems using the legacy Master Boot Record (MBR) partition scheme), use the following utilities.
1. Installing boot0 (The Boot Manager)
boot0 is the code placed in the MBR (sector 0) of the disk. It allows you to select which partition to boot from during startup.
  • To install the standard boot manager:
    Use boot0cfg to write the MBR code to your disk (e.g., ada0):
    bash
    Code: 
    boot0cfg -B ada0
    Wees voorzichtig met code.
    • -B installs the boot code.
    • Alternatively, you can use fdisk (legacy): fdisk -B -b /boot/boot0 ada0.
  • To configure boot0:
    You can set options like the default slice or the timeout (ticks):
    bash
    Code: 
    boot0cfg -s 1 -t 182 ada0
    Wees voorzichtig met code.
    (Sets the default boot slice to 1 and timeout to 10 seconds; 182 ticks
    ≈is approximately equal to
    ≈
    10s).
2. Installing boot1 and boot2 (The Boot Blocks)
boot1 and boot2 are conceptually part of the same program but are split for space reasons. They are installed into the first track of the FreeBSD slice (partition) itself.
  • Using bsdlabel:
    To write these stages into a specific slice (e.g., slice 1 on ada0):
    bash
    Code: 
    bsdlabel -B ada0s1
    Wees voorzichtig met code.
    • The -B flag tells bsdlabel to obtain the boot blocks from /boot/boot (which is a concatenated version of boot1 and boot2) and write them to the beginning of the slice.
  • Manual installation (rare):
    If you need to specify different boot files, you can use:
    bash
    Code: 
    bsdlabel -b /boot/boot1 -s /boot/boot2 ada0s1
```
    Wees voorzichtig met code.
Summary Table
Stage File PathLocationInstallation Tool
Stage 0 (boot0)/boot/boot0Master Boot Record (MBR)boot0cfg -B
Stage 1 & 2 (boot1/2)/boot/bootFirst track of the FreeBSD Slicebsdlabel -B
Note: If you are using a GPT (GUID Partition Table) instead of MBR, you typically do not use boot0. Instead, you use gpart bootcode to write to a freebsd-boot partition:
bash
Code: 
gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 ada0
```
 
I have an old 320GB MBR disk with two NTFS partitions which is normal on Windows system.

This disk has 993K free at the start of the disk and 1.3M at the end.

Can I make use of this?
 
https://www.google.com/search?q=how+to+shrink+ntfs+partition+and+filesystem&newwindow=1&sca_esv=41cf0e5ea23eebf2&sxsrf=AE3TifP68a1H6XhaKuy6fCapzid4Gsxs6g:1767311844825&udm=50&fbs=AIIjpHw2KGh6wpocn18KLjPMw8n5VMz2-jUCsgxQfgddG5unn65s6qmquXjyGdRslDl9Sq1WrxVU77MwSHWsfb0o-f-ofTmcS8fL4npCvRMCyRn5oM7GfsEE9WHWC-uPwxSzqAafsAf6grxrbeOfG_QfXccePztBSpXjDV_jnbb1EOvA1Xeoj6vwe_twdTDxMe1VHXqVr9Fl&aep=1&ntc=1&sa=X&ved=2ahUKEwiLn9_VxeuRAxXrVaQEHfLmI0AQ2J8OegQIERAE&biw=1994&bih=955&dpr=0.8&mstk=AUtExfCIkWrdWGTNcnm_A25BB3-Y7E5YKGZaAIXbKJ8aKZ98BAFsxJpwolqe1PS0HG89vrLtnhFVhtW8kBLFzFKDrZlXH_SrzcftJhVeiUUeM8UfN7Szcw8U7M0iNg_gyW3oueXRCrxS6HmYFiwDfguwhpgY80AwrTDDQZUjtbQf1gMjImvQTi9_RmuU7PvD2Q9Occed9hnmA2ScDFJNPWhQdEB6Ee3gLp48zfQ8Tai83TIDjtaduL8M4nnZ8JOx8rkJhUeTIotIWXSXN9d1Jln8tU929Ic_dDH0poIPyOv-SHArWy2b5S1AsKEvA5WQ18RHGtPhMVGihd6Gxg&csuir=1&mtid=5wlXadPqIZ--nsEPoISQiQc

And

https://www.google.com/search?q=shrink+ntfs+and+install+linux+how+to&newwindow=1&sca_esv=41cf0e5ea23eebf2&sxsrf=AE3TifNYDYAKbpropP_nzyAEULcWgnZmEw:1767311942328&udm=50&fbs=AIIjpHw2KGh6wpocn18KLjPMw8n5HCaddYJs9ynEoN2Nrpl8J9RYrWbd46FUMNeemvNeoaP54O9348gG4X5CW6R1O9Yu2h9trQl4a73sHIc-UtjfkJHuUp19tBWRwyFfjIsLA5sJzliI9xi2a5-OIXuryK7RWi8ITkh4Hw4gm9ibioXv8x-B3Q_ooM3RElZ4HnCEyvmY2DLo&aep=1&ntc=1&sa=X&ved=2ahUKEwjvmZ6ExuuRAxUmNvsDHSVQLT4Q2J8OegQIEhAE&biw=1994&bih=955&dpr=0.8&mtid=TgpXaaq8Ep--nsEPoISQiQc&mstk=AUtExfAavyNA0e6qPvOQb3gke_2CccxcrAaPhhx1S25gSKzRJvtBz0YWpQ_5y3eRbJUx56GJ0c2Igr_Pi0TXrTgQKtKCnP48psparvWXnV8JsNJSIXw7wxLsWheee9RPjalJHbNX_AsK-HyGVmjcSP-jZHideo4Eto7VNiOwxAPcrVVH3oVlP0YXRL9qsPlVp9mB8gLy3QY9kgBbXbpbxeOIDARda6Zf3U92oyWO5io6HQl8yuAIgnjr7zrcwxmj1LJt73UkSuh1LQ9FLzWxpnHmyy1I4HahzVFePxR_r1iKVSMkrRCOHQjVIX-75ujj4YvY4JTYFVMMZILYRA&csuir=1
 
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