# The Boot Manager and Boot Stages



## balanga (Apr 2, 2020)

Just reading The FreeBSD Handbook regarding *The Boot Manager and Boot Stages*

I couldn't help noticing





> Other operating systems, in particular Windows®, have been known to overwrite an existing MBR with their own. If this happens to you, or you want to replace your existing MBR with the FreeBSD MBR then use the following command:




```
# fdisk -B -b /boot/boot0 [I]device[/I]
```

I've only been using FreeBSD for a few years but I don't remember fdisk being available in that time


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## Emrion (Apr 2, 2020)

`fdisk` is outdated (as well as some explanations in the Handbook). `fdisk` is intended to be used for a MBR scheme. `gpart` is meant to replace it, even for dealing with MBR.

Most of the "recent" installations are made on a GPT scheme, no matter the OS. So, don't use `fdisk` unless you want to play and you know exactly what you are doing ;-).

By the way, the MBR boot program of Windows 7 is perfectly able to start a FreeBSD install if the partition scheme is MBR, the BSD slice is activated and the root file system is UFS. Just saw that recently.


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## msplsh (Apr 2, 2020)

`gpart bootcode`, specifically

(edit)
Yes, fdisk has been around since 1993, it's just not particularly useful for BSD labels or GPT disks, perhaps why you haven't seen it in use.


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