[DOCUMENT] Re: Intel Macs that boot FreeBSD?

[Maxim Sobolev]

Some progress: further investigation revealed that cdboot has been 
hanging when trying to enable A20 line, apparently Mac simply don't have 
relevant legacy hardware. After commenting out appropriate routine call 
in cdboot I was able to get loader working just fine. The loader works 
normally, but unfortunately attempt to start kernel hangs up machine.

I suspect that either Mac doesn't have real text mode or kernel also 
waits for some nonexisting legacy hardware indefinitely.

-Maxim

Bruce M Simpson wrote:
> On Sat, Apr 08, 2006 at 03:43:58AM -0700, Luigi Rizzo wrote:
>> Ii wonder if we can do more progress if we use
>> a picobsd-like approach namely bypass btx and load the kernel
>> directly. Reading your list we may well get stuck at the pci
>> probe, but at least we should see the initial kernel messages.
> 
> I would suggest that anyone who wants to get FreeBSD booting on the
> mini-mac purchases a port 0x80 POST diag card (<$10 on eBay), and
> instruments the early boot paths to output to such a device.
> 
> If hacking kernel code then probably quicker to just use NFS and
> PXE for starter bootstrap :-)
> 
> Of course those of us who are lucky enough to have a PCI logic analyzer
> (not me, though I bought an FPGA card explicitly for this purpose,
> ENOTIME to learn hardware design language) will be able to do this
> right away.
> 
> It shouldn't be too difficult to implement PCI Configuration Register
> Type 1 support.  Ideally of course we'd support EFI natively w/o the shim.
> 
> Regards,
> BMS
> 
>