[linuxsh-dev] [RFC] machtype generation

[Paul M. <le...@li...>]

This issue was initially brought up in the deviceinfo thread about a
month ago, at which point I noted that I had a local script I was
playing with to see about doing automatic machtype generation to clean
up quite a bit of the include/asm-sh/machvec.h mess.

At the moment, the current interface looks like the following:

	- Add a 1-bit value to sh_machine_vector to flag your
	  current board type
	- Define MACH_xxx repeatedly through endless ifdefs to
	  determine the current board type (also wrap through
	  the sh_machine_vector struct if CONFIG_SH_GENERIC is
	  set).

This approach is ugly for quite a lot of reasons, least of all the fact
that everytime a new board is added, structure size changes, and more of
these ugly macros are generated.

As a solution to this, I've essentially created a stripped-down clone of
the ARM tree's mach type generation script. For this interface, I
propose that we maintain a master-list of supported boards and their
associated CONFIG options in some place like arch/sh/tools/mach-types.

As an initial implementation, I have mach-types looking something like
this:

	#
	# List of boards.
	#

	#
	# MACH_<xxx>		CONFIG_<xxx>
	#
	SE			SH_SOLUTION_ENGINE
	7751SE			SH_7751_SOLUTION_ENGINE		
	HP600			SH_HP600
	HP620			SH_HP620
	HP680			SH_HP680
	HP690			SH_HP690
	HD64461			HD64461
	HD64465			HD64465
	SH2000			SH_SH2000
	SATURN			SH_SATURN
	DREAMCAST		SH_DREAMCAST
	BIGSUR			SH_BIGSUR
	ADX			SH_ADX


I suppose some more work could be done here to simplify things further
(or potentially elaborate some more), but as I said, this is just an
initial implementation.

This list will then be passed through a script that will be invoked by
arch/sh/Makefile early-on (probably at the same time that the symlinks
in include/asm-sh are made), and will generate include/asm-sh/machtype.h
automatically. This header can then be referenced directly and we can
sanely gut most of machvec.h.

As an example of an auto-generated machtype.h, I have the following:

	/*
	 * Automagically generated, don't touch.
	 */
	#ifndef __ASM_SH_MACHTYPE_H
	#define __ASM_SH_MACHTYPE_H

	/*
	 * We'll use the following MACH_xxx defs for placeholders for
	 * the time being .. these will all go away once sh_machtype is
	 * assigned per-board.
	 *
	 * For now we leave things the way they are for backwards
	 * compatibility.
	 */

	/* Mach types */
	#ifdef CONFIG_SH_SOLUTION_ENGINE
	  #define MACH_SE		1
	#else
	  #define MACH_SE		0
	#endif
	#ifdef CONFIG_SH_7751_SOLUTION_ENGINE
	  #define MACH_7751SE		1
	#else
	  #define MACH_7751SE		0
	#endif
	#ifdef CONFIG_SH_HP600
	  #define MACH_HP600		1
	#else
	  #define MACH_HP600		0
	#endif
	#ifdef CONFIG_SH_HP620
	  #define MACH_HP620		1
	#else
	  #define MACH_HP620		0
	#endif
	#ifdef CONFIG_SH_HP680
	  #define MACH_HP680		1
	#else
	  #define MACH_HP680		0
	#endif
	#ifdef CONFIG_SH_HP690
	  #define MACH_HP690		1
	#else
	  #define MACH_HP690		0
	#endif
	#ifdef CONFIG_HD64461
	  #define MACH_HD64461		1
	#else
	  #define MACH_HD64461		0
	#endif
	#ifdef CONFIG_HD64465
	  #define MACH_HD64465		1
	#else
	  #define MACH_HD64465		0
	#endif
	#ifdef CONFIG_SH_SH2000
	  #define MACH_SH2000		1
	#else
	  #define MACH_SH2000		0
	#endif
	#ifdef CONFIG_SH_SATURN
	  #define MACH_SATURN		1
	#else
	  #define MACH_SATURN		0
	#endif
	#ifdef CONFIG_SH_DREAMCAST
	  #define MACH_DREAMCAST	1
	#else
	  #define MACH_DREAMCAST	0
	#endif
	#ifdef CONFIG_SH_BIGSUR
	  #define MACH_BIGSUR		1
	#else
	  #define MACH_BIGSUR		0
	#endif
	#ifdef CONFIG_SH_ADX
	  #define MACH_ADX		1
	#else
	  #define MACH_ADX		0
	#endif

	/* Machtype checks */
	#define mach_is_se()			(MACH_SE)
	#define mach_is_7751se()		(MACH_7751SE)
	#define mach_is_hp600()			(MACH_HP600)
	#define mach_is_hp620()			(MACH_HP620)
	#define mach_is_hp680()			(MACH_HP680)
	#define mach_is_hp690()			(MACH_HP690)
	#define mach_is_hd64461()		(MACH_HD64461)
	#define mach_is_hd64465()		(MACH_HD64465)
	#define mach_is_sh2000()		(MACH_SH2000)
	#define mach_is_saturn()		(MACH_SATURN)
	#define mach_is_dreamcast()		(MACH_DREAMCAST)
	#define mach_is_bigsur()		(MACH_BIGSUR)
	#define mach_is_adx()			(MACH_ADX)

	#endif /* __ASM_SH_MACHTYPE_H */

Also, if anyone is interested in the script for this, its nothing
special, and is more or less just a quick and dirty hack. I've attached
that as well, incase anyone wants to look it over.

I realize this doesn't fixup the ifdef mess, but as noted in the
comments above, its a temporary fix until something like sh_machtype
gets introduced, and can then be set in board-specific setup code.

If no one has any problems with this, I'll merge it into HEAD in the
next few days.

Comments?