[U-Boot-Users] lkc support for U-Boot My $0.02 worth

[Holger Schurig]

> I still see technical issues; for example, I have not  the  slightest
> idea how longish definitions like:

Not at all. However, I have the feeling that they are not that common. Only 
some board has this here and then.


But those long stuff could stay in the *.h file, if needed.

config EXTRA_ENV_SETTINGS
   char "kernel environment settings"
   depends !SPECIAL_BOARD

and in include/config/special_board.h

#undef CONFIG_EXTRA_ENV_SETTINGS
#define CONFIG_EXTRA_ENV_SETTINGS \
  "ten " \
  "thousand " \
  "lines"


> Also,
> I  fear  that  adding new features will become much harder, as you'll
> have to continually extend  the  config  setup.

For me it looks EASIER. A complete description of what is configurable is in 
the config.in files. Right now, I have to do things like

grep '^#if' `find -name '*.c'` | sort | unique

to find out what is actually configurable. And then it's only slightly 
documented, and dependencies are not laid out clearly.



> And  finally  -  has
> anybody  benchmarked the speed of such a new config scheme?

I doubt there is much difference...   once you've run make 
config|xconfig|oldconfig|menuconfig, you have to files. One is includeable by 
"Makefile"s, the other one into C programs.

You simply include this and that's it. I can't see why this should slowdown 
the compilation process.

One thing that might be a little time difference is the

cp board/<boardname>/def-configs .config
make oldconfig.

However, running "make oldconfig" on the current Bitkeeper tree of 
www.openzaurus.org is negligible:

/usr/src/buildroot-oz# touch packages/config.in
/usr/src/buildroot-oz# touch .config
/usr/src/buildroot-oz# times make oldconfig
0.22user 0.09system 0:00.32elapsed 94%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (5351major+2500minor)pagefaults 0swaps

But then again the combined length of all config.in of this project is only 
754 lines with now only 202 configurable variables (I have an 850 MHz AMD 
with 1967 bogomips and the hard disk cache was "warm").


Greetings, Holger