Not sure of the code for GRUB, but it seems to do a lot of the same. 
Supposed to be able to boot *BSD as well as many other x86 OS's.

ciao!

leam


Peter Seebach wrote:
> In message <20030908233518.B59F07B43@berkshire.research.att.com>, "Steven M. Be
> llovin" writes:
> 
>>>(For the curious:  ipfw, which is not in any way related to the FreeBSD
>>>gizmo of the same name, and the boot.default/boot.define stuff allowing
>>>all sorts of magical kernel tweaking to be stored in nice editable text
>>>files.)
> 
> 
>>Let me second that.  BSDi's IP filtering gives you much finer control 
>>over what is passed, with (to me) more intuitive semantics.  And the 
>>boot.default stuff was extremely useful to me when dealing with some of 
>>the quirks of IBM Thinkpad booting.
> 
> 
> Unfortunately, I don't believe either will ever be given away as free source.
> 
> That said, I think both are implementable without TOO much work.  ipfw does
> a fair bit of magic, but I think under the hood it consists mostly of a
> compiler-to-BPF and a better selection of places for BPF filters to be
> inserted.
> 
> The boot.default stuff, well, it's a fair bit of work, but MAN is it useful.
> For those who have never seen it:
> 	* The boot loader loads a file called /etc/boot.default
> 	* It can also take commands entered by hand
> 	* Commands may pass parameters to the rest of the boot loader or
> 	  the kernel
> That's it, but consider the following /etc/boot.default lines:
> 	# suppress ultra2 probe on target 2 on aic0, because we happen
> 	# to know that the disk's firmware is dodgy
> 	-parm aic0 ultra2=all-t2
> 	# only probe up to 1GB of memory on dodgy old pentium board
> 	-extendend 1G
> 	# load ramdisk
> 	-ramdisksize 2048k
> 	-ramdiskfile filesys.gz
> 	# load kernel from one disk, put root on another
> 	-kernel sd(0,0):/netbsd.old
> 	-rootdev wd(0,0)
> 	# force disable of ehci driver on this machine
> 	-dev ehci* port=-1
> 
> You get the idea.  All *sorts* of cool stuff, and a standard interface
> for drivers to announce their parameters.
> 
> -s
> 
> 
>