Fun building cross versions of ldd and readelf.

[Rob Landley]

So I'm building a cross compiler toolchain, and I'd like to have ldd and 
readelf in there.  Unfortunately, they want to link against uClibc, and if I 
just built an arm version of uClibc it's kind of silly to do a make clean and 
then build an x86 version of uClibc just to link ldd and readelf against.  In 
fact, they seem to work linked against the host C library just fine, if I do:

$CC -Os -s -I include utils/readelf.c -o readelf
$CC -Os -s -I ldso/include utils/ldd.c -o ldd

Except that although this works fine after an x86 build and an armv4l build, 
but it breaks spectacularly after a mipsel build.  It can only be the 
headers, so I need to make distclean && make allyesconfig.

Question #1: Why on EARTH does "make allyesconfig" (from the February 14 
snapshot) stop and ask me for stuff?  Isn't the _point_ of make allyesconfig 
that it doesn't block?  How did this break?

Quick workaround "yes '' | make allyesconfig" and...  the build breaks again, 
because I need to "make headers".  Right.  That does...

> ( cd extra/locale/; wget --passive-ftp
> http://www.uclibc.org/downloads/uClibc-locale-030818.tgz ) --15:56:23-- 
> http://www.uclibc.org/downloads/uClibc-locale-030818.tgz =>
> `uClibc-locale-030818.tgz'
> Resolving www.uclibc.org... 140.211.166.42
> Connecting to www.uclibc.org|140.211.166.42|:80... connected.
> HTTP request sent, awaiting response... 200 OK
> Length: 236,073 (231K) [application/x-gzip]
>
> 100%[====================================>] 236,073      321.78K/s
>
> 15:56:24 (321.11 KB/s) - `uClibc-locale-030818.tgz' saved [236073/236073]

Question #2: Why is "make headers" calling _wget_ halfway through?  Since when 
does the uClibc build work like buildroot and download stuff halfway through?

Anyway, the way to make it work appears to be:

  make distclean
  make allnoconfig
  make headers KERNEL_HEADERS="${CROSS}/include"
  $CC -Os -s -I include utils/readelf.c -o readelf
  $CC -Os -s -I ldso/include utils/ldd.c -o ldd

Just FYI.

Rob
-- 
"Perfection is reached, not when there is no longer anything to add, but
when there is no longer anything to take away." - Antoine de Saint-Exupery