boot0cfg, how to use -m option

Warren Block wblock at
Sat Oct 24 01:14:44 UTC 2009

On Sat, 24 Oct 2009, Sandra Kachelmann wrote:

> I installed the FreeBSD boot loader and have now the following options:
> F1  Win
> F2  Win
> F3  FreeBSD
> F4  FreeBSD
> F6  PXE
> Now I wan't to enable only partition 1 and 3 and PXE (F1, F3, F6).
> The manpage of boot0cfg says:
> -m mask
>    Specify slices to be enabled/disabled, where mask is an integer
> between 0 (no slices enabled) and 0xf (all four slices enabled).
> which I find very confusing.
> Could someone explain me what value (and why?) I have to chose to
> achieve the above mentioned.

I can't say I've used that, but it appears to just be bit values.  They 
should be:

Partition    Mask bit value
1            1
2            2
3            4
4            8

Add together the ones you need.  For partitions 1 and 3, it would be 
1+4, so... 5.  I don't know if boot0cfg wants that as a plain decimal or 
the leading 0x of a hex format, and the man page doesn't explicitly say. 
It implies hex, but I suspect it wants decimal.  Again, untested.

-Warren Block * Rapid City, South Dakota USA

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