Re: Aha!

[Pete Popov <ppopov@pacbell.net>]

>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 9/1/00, 1:11:51 PM, "Christopher C. Chimelis" <chris@debian.org> wrote 
regarding Re: Aha!:


> On Fri, 1 Sep 2000, Pete Popov wrote:

> > The mips1/2/3/4 are different mips instruction set architectures.
> > Processors that are mips4 compliant, for example, also have instruction
> > compatibility with the previous  architectures -- mips1/2/3.  Thus, mips3
> > doesn't mean R4000, but the R4000 might be a mips3 cpu (the 5000 is
> > mips4).
> >
> > It would be nice to get gcc/binutils fixed for all ISAs, but if you have
> > to target a certain ISA, start with mips3.  Most newer processor are
> > either mips3 or mips4 cpus, so that would be of the most benefit to
> > mips-linux, imho.

> That's what I figured.  The problem is, the mips3 target is a 64-bit one,
> which may affect the mips port in general.  Since this port is in it's
> infancy (from my observation of packages available and condition of the
> toolchain), I'm wondering if it might be better off to start the mips64
> port now and go from there (at least on my end).  Once the mips1 ISA is
> better supported, then continuing the 32-bit mips port will be feasible,
> from a toolchain standpoint.

The mips3/4 cpus currently supported are supported in 32 bit mode; I've 
never tried the mip64 port myself ... and I'm not sure what the above 
mentioned concern is.

I think I just changed my mind about the mips ISA support :-) Currently, 
it appears that the Indys and Indigo2s are the "best" supported SGI 
systems. However, mips is much more than just SGI.  There are many 
companies using mips cores for building SOCs, and mips32 is one of the 
popular cores.  In the embedded market, mips has a very strong presence, 
and embedded linux is the future (please note that my opinion is highly 
biased in that regard).  So, I think it would be great to bring the 
toolchain up to date, including mips 1/2 support. There is some very cool 
mips hardware coming down the pipeline and, as I said, having an up to 
date mips isa 1 and 2 (as well as 3 and 4) support would be great.

> > If you're interested in mips in general, the best book out there, in my
> > opinion, is 'See Mips Run' by Dominic Sweetman.

> That's pretty much what I gathered.  Is it good from a standpoint of
> understanding the ISAs and the differences in the MIPS family from an asm
> point of view?

I think so. It has an entire chapter on "Complete Guide to the MIPS 
Instruction Set", plus a chapter on assembler programming, an other 
chapter on c mips programming, etc.  It brings the entire mips history 
and architecture together in one book and covers pretty much everything 
(including the caches, tlbs, floating point, etc). You might still want 
to get the mips ISA specs from MIPS, but definitely do get this book.

Sorry for uneducated question, but you seem to be involved heavily in 
gcc/binutils?

Pete