RE: Porting question

[Gary Parnes <GaryP at logicpd dot com>]

> -----Original Message-----
> From: Andrew Lunn [mailto:andrew@lunn.ch]
> Sent: Tuesday, December 02, 2003 12:02 PM
> To: Gary Parnes
> Cc: 'Andrew Lunn'; 'ecos-devel@sources.redhat.com'
> Subject: Re: Porting question
> 
> 
> > It seems to me that the header file hal_ebsa285.h contains 
> a rich amount of
> > information specific to the SA-110 processor, not the 
> EBSA285 platform.
> > Couldn't we make the case that much of the header information -- and
> > possibly some code, such as hal_clock_initialize() & 
> hal_clock_reset() --
> > should be in the directory ../hal/arm/sa110/var, with the ebsa285
> > platform-specific stuff (e.g. initialization of the 21285) 
> residing in
> > ../hal/arm/sa110/ebsa285.
> 
> You could, but in practice i think its pointless. The 21285 companion
> chip is virtual undispensible. I would be surprised if anybody used
> the sa110 without the 21285. Also, Intel only produced the one decide
> around the sa110 as far as i know.
> 
>        Andrew
> 

Hey, I said one could make the case... I didn't say anything about actually
doing it. ;^)

Looking at what's currently in the source tree, there's very little that's
related directly to the LH754xx series.  The AEB-1 involves a Sharp LH77790
CPU, but the features on that one are notably different (it has cache, for
one thing).  Also, there's a lot of stuff defined in the source code that
should be in header files (see aeb_misc.c).

I'm going to use the CDL for the ARM integrator -- since that guy is also an
ARM7TDMI core with no cache unit -- and go from there.  I'll probably define
the register locations, masks, settings, etc. using a style similar to
hal_sa11x0.h.  I really like that header style; the ability to use the
header for both C and assembly preprocessing is very cool.

The data sheet for the LH75401 is actually a multi-purpose data sheet; it
describes the workings of the LH75400, LH75401, LH75410, and LH75411 in
parallel.  The most obvious differences seem to relate to the capabilities
of the on-board video controller.  So I think we can safely lump those cores
together.  And those four products are the only ones that start with a
prefix of "LH754", so... what I'm looking at is:

../hal/arm/lh754xx/var/current/... for the CDL, headers, & code common to
the LH754xx series of microprocessors
../hal/arm/lh754xx/zoom/current/... for the CDL, headers, & code specific to
our Zoom DevKit product

Raise objections if you got 'em!

Thanks for your time, everbody...

--Gary Parnes

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