[U-Boot] RFQ: Makefile cleanup

[Wolfgang Denk]

Hi,

I'm working on a few patches to get rid of the remaining scripting
in the Makefile, i. e. to move the remaining board descriptions into
board.cfg; this work makes use of Marek Vasut's patch to extend the
mkconfig script so it can process an additional "options" field.

For example, a board entry could now look like this:

TQM8260_AB  powerpc  mpc8260  tqm8260  tqc  -  TQM8260:MPC8260,200MHz,L2_CACHE,BUSMODE_60x

Read this as:

"make TQM8260_AB_config" will set up a build for the following board
definition:

	ARCH   = powerpc
	CPU    = mpc8260
	BOARD  = tqm8260
	VENDOR = tqc

The options field can contain multiple options: a board configuration
name, optionally followed by a colon (':') and a list of options,
which are separated by comma (','). In case there's a simple option
like 256M_U_BOOT, this expand to "#define CONFIG_MK_256M_U_BOOT 1" in
config.h . In case there's an assignment, like "RAM=8192", it expands
to "#define CONFIG_MK_RAM 8192" in config.h .

    Example:

        FOO:HAS_BAR,BAZ=64

    means:
        - the name of the board config file is include/configs/FOO.h
        - the generated file include/config.h will contain these
          lines:
    
                #define CONFIG_HAS_BAR 1
                #define CONFIG_BAZ  64
    
In our example above, include/config.h will contain the following
settings:

	#define CONFIG_MPC8260  1
	#define CONFIG_200MHz   1
	#define CONFIG_L2_CACHE 1
	#define CONFIG_BUSMODE_60x      1
	#define CONFIG_BOARDDIR board/tqc/tqm8260

So far, so good.


With this I can convert a large number of boards from the Makefile to
boards.cfg - but I still have a problem with those that not only add
settings to include/config.h, but that also add custom settings to
some config.mk file, typically to adjust the TEXT_BASE setting, for
example like this:

Makefile:

	...
	@echo "TEXT_BASE = 0x01000000" > $(obj)board/amcc/acadia/config.tmp
	@echo "CONFIG_NAND_U_BOOT = y" >> $(obj)include/config.mk
	...

board/amcc/acadia/config.mk:

	...
	sinclude $(OBJTREE)/board/$(BOARDDIR)/config.tmp
	...
	ifndef TEXT_BASE
	TEXT_BASE = 0xFFF80000
	endif
	...
	ifdef CONFIG_NAND_U_BOOT
	...

The settings in include/config.h are visible in the Makefiles through
the automatically generated include/autoconf.mk; however, with the
mechanism above I cannot generate a "TEXT_BASE" setting as currently
all options automatically get prefixed with "CONFIG_".

Now I see two approaches for a solution:

1) I stop prefixing options with "CONFIG_" and write the full
   variable names instead.

   pro: I have full controll over which definitions I generate,
        and I can handle it at a single, central location.

   con: The lines in boards.cfg, which often are more than long
        enough, will become even longer. Our example above would now
        become:

	TQM8260_AB  powerpc  mpc8260  tqm8260  tqc  -  TQM8260:CONFIG_MPC8260,CONFIG_200MHz,CONFIG_L2_CACHE,CONFIG_BUSMODE_60x

2) I accept the prefix, and generate a definition for
   CONFIG_SYS_TEXT_BASE.  In the config.mk file, I replace the
   "sinclude ... config.tmp" by something like this:

	ifdef CONFIG_SYS_TEXT_BASE
	TEXT_BASE = $(CONFIG_SYS_TEXT_BASE)
	endif


   pro: The lines in boards.cfg don't get too long.

   con: I have to adapt a number or board specific config.mk files
        (but I have to do this anyway to remove the then obsolete
        "sinclude" lines.


At the moment my preference goes with 2), but I would like to hear if
this approach seems acceptable to others as well.

Or eventually somebody has a really clever idea how to tackle this...


Thanks in advance.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
There are bugs and then there are bugs.  And then there are bugs.
                                                    - Karl Lehenbauer