Re: NetBSD/virt68k booting multi-user

[Jason Thorpe <thorpej%me.com@localhost>]

> On Jan 6, 2024, at 12:02 PM, Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost> wrote:
> 
> thorpej@ wrote:
> 
>> I still have a little cleanup to do, but this should be ready to get hooked up into RELENG's automated tests soon.
> 
> Great news!
> 
> I think this virt68k on qemu can also be used to build pkgsrc binaries,
> but there is one concern.
> 
> According to virt68k/include/param.h, PGSHIFT is 12 so page size is 4KB.
> This means the virtual address space range is limited upto ~224MB
> on 040 pmap and it could be too small to build modern large toolchains
> like cmake.

I have plans(tm) for that.  Specifically, a new pmap that manages the 68040 MMU properly.

> I guess we can simply change PGSHIFT to 13, but I wonder we should
> also consider again to reorganize 040 pmap to make it possible to
> expand L2 STEs on demend, as mhitch@ mentioned back in 2009:
> https://mail-index.netbsd.org/port-m68k/2009/05/12/msg000143.html
> 
> Maybe we also have to consider about 3-level pmap like sun3x..
> https://mail-index.netbsd.org/port-m68k/2001/07/20/0003.html

That’s an idea, but that won’t work for the HP MMU on the 320 / 350.

-- thorpej