Re: Another multibooting option for the FAQ

I'm not sure if you were responding directly to my suggestion, or
misunderstood what I was suggesting. Maybe I can make it simpler...

Multibooting OpenBSD and Any Other OS can be done with
- a single drive, with lots of options that involve messing with
bootloaders, partitions, etc
- separate OSes on separate drives, where you select the OS to boot by
selecting it's drive in the BIOS boot device menu (not BIOS setup
screens)

All the multiboot info in the FAQ describes working with a single
drive, and a fair amount of space is given to Windows. I only
mentioned Windows because it's a common use case. The BIOS multiboot
method has nothing to do with the OSes involved.

Take it or leave it, but I think it's worth mentioning in the FAQ.

On Thu, May 13, 2010 at 1:16 PM, Austin Hook <[email protected]> wrote:
>
> There are probably 20 different ways to go about dual booting.  However,
the
> OpenBSD FAQ is not going to spend much time on saying how to use Windows to
> accomplish something.  I set up a dual boot machine recently, because I
> needed to use something on Windows, and I wrote a script to copy a modified
> first sector to the single hard drive, followed by a reboot, and so then
> just do a:
>
> sudo win
>
> to go to Windows.
>
> Then on Windows I installed Cygwin where I made a script that does the
> reverse, which I run as "./openbsd", which causes any subsequent reboot to
> return to OpenBSD.
>
> I'll leave it to you to figure out how to use dd and a hex editor to toggle
> the one byte in a copy of that first sector that makes the crucial
> difference.  The hardest thing for me was to figure out how cygwin could
> refer to the raw disk at sector 1 track 0 head 0.   I suppose there are
> utilities somewhere that could avoid using Cygwin (a Unix like subsystem to
> works on Windows), and just do the same thing and reboot directly.
>
> I don't figure there is much danger changing the first sector, if the
> criitial step is run under a script, so I don't think fancy dual booting
> code or bios's are necessary.
>
> Austin
>
>
> On Thu, 13 May 2010, John Danks wrote:
>
>> I just realized this one recently. Most modern BIOS allow you to press
>> a key on the POST screen and choose a boot device, even a specific
>> hard drive.
>>
>> All of the current multiboot options in the FAQ describe methods for
>> use with a single disk. An alternative then is to install Windows on
>> the first disk which the BIOS boots to by default, and then install
>> OpenBSD on a separate disk in the same machine. Simply press F10, F12
>> or whatever key your BIOS uses and choose the OpenBSD disk as your
>> boot device.
>>
>> This method saves you the trouble of messing around with partitions,
>> bootloaders and potential data loss, assuming you have an additional
>> drive, room in the case to install it and a BIOS that supports the
>> option to choose an alternate boot device.