Subject: Re: Netscape.
To: Chris G Demetriou <Chris_G_Demetriou@lagavulin.pdl.cs.cmu.edu>
From: Jason Downs <downsj@SJ.Xenotropic.COM>
Date: 03/12/1995 14:17:21
In message <199503120559.AAA03303@pain.lcs.mit.edu>,
Chris G Demetriou writes:
>> I'm not sure what the issues are surrounding converting the
>> hp300 port (the port that I use most) to 8k pagesize
>> so it can run binaries from the other 68k ports...
>Then Charles said:
>> It's not necessary to `convert' the port in order to do that.
>to elucidate a bit:
>To get the hp300 (the only m68k4k port) to properly work with m68k8k
>binaries, one needs only to add a hook for a machine-dependent exec
>type, which knows how to do the binaries' mappings correctly. That
>hook is relatively easy to write.
>It's a bit harder to write a similar hook for m68k8k ports, to allow
>them to run the hp300 (m68k4k) binaries. In fact, it's impossible
>to write a "m68k8k machine runs m68k4k binaries" hook to run standard,
>demand-paged ZMAGIC binaries that is as memory- and i/o-efficient as
>is running them on the hp300.
>some (including me 8-) would argue that the hp300 should be converted
>to use 8k page sizes for all of its binaries. This would allow hp300
>and other m68k ports' binaries to be completely interchangeable, with
>no special hooks, etc. It would cost (on average) 4k extra disk space
>per binary, on hp300 systems. That cost comes out to 2-3M, given an
>average extra space per binary of 4k, and given between 500 and 750
>binaries per system (the average, i'd say, at least looking at one of
>the hp300's i've access to).
I think that the 4k page size should remain the default for the hp300,
as far as what the kernel expects as it's `default' binary format.
8k support should be probably be added to the kernel, as you say. As
an option. Then it only stands to reason that the appropiate tools
(gas, ld, etc.) should be whacked to be able to produce either 4k or
8k object files, depending on command line switches.
There's nothing wrong with making the hp300 do 8k page binaries, so
long as you can still exec 4k binaries, and the tools can still produce
them. I'd even say it'd be ok for the tools to produce 8k page-size
object files by default.
>I think that that waste of space is worthwhile, because it allows:
> (1) all m68k ports to use binaries interchangably, with no special
> hooks, options, or ineffiencies,
> (2) hp300's to easily (by default, even!) compile binaries
> that will run on the other m68k ports, and vice-versa.
> Last i checked, this wasn't possible, and was bloody
Obviously, this discussion belongs on port-hp300.