On 18 Sep 2000 bsh@grotto.iijnet.or.jp wrote:

: + MACHINE_ARCH=sh3 is for big endian since evbsh3 and mmeye are big
:   endian platform, while dreamcast is little endian.  We need new
:   MACHINE_ARCH, say sh3el.

: + Do we want sh3eb when we have sh3el?

If there is precedent on another platform, we should adopt those names.

: + Is it OK to set MACHINE_ARCH=sh3el and MACHINE=evbsh3 for dreamcast,
:   and MACHINE_ARCH=sh3 MACHINE=evbsh3 for evbsh3? It looks bad.
:   We need MACHINE=dreamcast.

This is fine.  MACHINE describes the hardware architecture; MACHINE_ARCH
describes the object format (and CPU types used in the object format).

=====

On Mon, 18 Sep 2000, SAITOH Masanobu wrote:

: The reason of why I don't split it is:
: 
: 	1) the difference of "eb" and "el" in evbsh3 is
: 	   include/endian_machdep.h only.

The difference is in object format.  This is why mipseb and mipsel split.  
This split is _required_ before 1.6, if both little and big endian sh
systems will be releasing 1.6 binaries.

: 	2) I don't want to modify many Makefiles like:
: 
: 		SUBDIR= ${MACHINE:C/evbsh3e[bl]/evbsh3/} (see below)
: 		.if ${MACHINE} != ${MACHINE_ARCH}
: 		ARCHSUBDIR= ${MACHINE_ARCH:C/mipse[bl]/mips/:C/sh3e[bl]/sh3/}

There is discussion about simplifying this with a "cpu" naming scheme.  The
way this currently works for mips is a hack, too.  8-(

: And more, MACHINE (not MACHINE_ARCH) can split into evbsh3eb and evbsh3el,
: too. Most evaluation board can select the byte order by DIP switch.

Only one primary object format is in use at any time (opposite-endian
binaries need to run under emulation).  The correct MACHINE and MACHINE_ARCH
definitions could be provided with "#ifdef" supplied by the config file.  

Userland code should not rely on <sys/param.h> for the proper values;
uname() and sysctl() exist for that.

: 	#if 1
: 	#define _BYTE_ORDER _BIG_ENDIAN
: 	#else
: 	#define _BYTE_ORDER _LITTLE_ENDIAN
: 	#endif

This could use same #ifdef as MACHINE and MACHINE_ARCH.

=====

On Mon, 18 Sep 2000, David Brownlee wrote:

: 	Maybe this would be a good time to move to /sys/cpu/sh3 - I
: 	believe port-arm32 is discussing splitting arch/arm32 into
: 	individual kernel directories (which is somewhat related)

And, additionally, we need a MACHINE_CPU definition (long ago proposed by
jonathan when mipse[bl] split), inherited by make, which can make using
unified cpu source less painful.

I'm not sure that a separate "cpu" subdirectory is necessary; we've had
powerpc, m68k, and mips for some time.  But a way to identify the CPU type
name (where MACHINE_ARCH specifies things like word-size and endianness)
would be useful.

-- 
-- Todd Vierling <tv@wasabisystems.com>  *  http://www.wasabisystems.com/
-- Speed, stability, security, and support.  Wasabi NetBSD:  Run with it.