questions about makefiles

[David Byron <dbyron at coactive dot com>]

I've been working with the 2.2.4 tarball and trying to build it on
i686-linux for an arm-linux target.  The special part appears to be that my
target is big-endian, and the arm tools by default are set up for little
endian.

So, I did what I thought was the right thing and set up CFLAGS and LDFLAGS
appropriately and configured and made.  To get things to build properly, I
had to change some makefiles to look at some environment variables where
they weren't before.  Here are my settings:

  CC=arm-linux-gcc
  CFLAGS="-msoft-float -mcpu=arm9 -mbig-endian"
  LDFLAGS="-Wl,-EB,-N -Wl,--oformat=\"elf32-bigarm\""

And, here are the arguments I used when configuring:

    configure --target=arm-linux --host=arm-linux --with-headers=<the place
where my kernel headers live for my target> \
 --prefix=<the place I want to install to, somewhere under my home
directory> \
 --build=i686-pc-linux-gnu       \
 --disable-shared \
 --disable-profile \
 --without-cvs \
 --enable-add-ons=linuxthreads \
 --enable-static-nss \
 --with-elf \
 --without-gd

Rather than show you guys the diffs, I think it's easier to explain them...

- In csu/Makefile (line 132), I added $(CFLAGS) to the link-relocatable
definition.  Adding $(LDFLAGS) instead works as well.  Without this,
csu/crt1.o didn't link because the object files are big-endian and the
linker is trying to build something little-endian.

- added $(CFLAGS) to +prector and +postctor in Makeconfig (lines 509, 510).
Without this, iconv/iconvconfig failed to link because the crtbegin.o and
crtend.o being picked up were little endian and the other object files are
big-endian.

- added $(CFLAGS) to +link and +link-static in Makeconfig (lines 385, 397).
Without this, -lgcc indicates the little endian libgcc.a when linking
iconv/iconvconfig (+link) and elf/sln (+link-static).  $(LDFLAGS) is already
passed to $(CC) here, but I'm not sure how to can change it to make this
work for me.  (How come iconv/iconvconfig is linked with +link instead of
+link-static when I specified --disable-shared?)

- added $(ASFLAGS) to Makerules (lines 315, 317).  This one confused me.
Even after making CPPFLAGS=$CFLAGS and exporting it as I do for the other
variables, it doesn't seem like Makerules picks it up.  But, if I use
ASFLAGS=$CFLAGS, it works fine.  In other words:

CPPFLAGS=-msoft-float -mcpu=arm9 -mbig-endian make

doesn't work

but after changing Makerules, 

ASFLAGS=-msoft-float -mcpu=arm9 -mbig-endian make

does.  I'm pretty sure there's a better fix than this one for this problem.
Without a change like this, assembly files get built for little-endian, and
the links fail.  Perhaps line 625 of Makeconfig is the line that needs to
change to take CPPFLAGS from the outside world.

As a caveat, a hello world program working based on the glibc I built with
these changes doesn't work, but if folks can confirm that I did the right
thing (or a right thing) here, it would help a lot.

I'm pretty new to glibc, so I don't know if this is the way the owner would
have changed the makefiles.  If not, can someone suggest another solution?
I looked in cvs, and changes like this don't seem to have been made since
2.2.4.

Thanks much for your help.

-DB
---
David Byron                     dbyron@coactive.com
Coactive Networks, Inc.         http://www.coactive.com
28 Liberty Ship Way             voice:(415)289-7800
Sausalito, CA  94965            fax:(415)289-1320