Re: [DOCUMENT] Re: Intel Macs that boot FreeBSD?

From: Scott Long <scottl_at_samsco.org>
Date: Sun, 09 Apr 2006 16:33:44 -0600
Maxim Sobolev wrote:

> 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
> 

The Windows 1st stage installer uses text mode, and that runs just fine.
I'm pretty sure that the linux efforts also just use plain text mode.
Text mode is a property of the video BIOS anyways, and from what I
gather the Macintel video hardware is using video BIOSes that are close
to stock.  I'm guessing that FreeBSD is doing some BIOS call that isn't
emulated or is emulated poorly.  FreeBSD could also be trying to twiddle
some MSR that is behaving as expected (like how the amd64 port used to
enable the NX MSR by default, causing early 64-bit Intel chips to lock
up).

Scott
Received on Sun Apr 09 2006 - 20:33:47 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:54 UTC