[gentoo-embedded] Clarification of 5.e Embedded Handbook

[gentoo-embedded] Clarification of 5.e Embedded Handbook

[John Poole]

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I'm trying to install a cross compiler on my AMD64 for arm (SheevaPlug) 
and have been following your Gentoo Embedded Handbook at 
http://www.gentoo.org/proj/en/base/embedded/handbook/index.xml

I do not fully understand Chapter 5 "Cross-Compiling with Portage", 
specifically the section 5.e on "Helper: pkg-config".

The instructions state:

vvvvvvvvvvvv

Many packages are moving to installing pkg-config files (*.pc) and using 
those to discover needed libraries and includes. To ease the build 
process, you should install a pkg-config wrapper for your target which 
will tell pkg-config to only search your cross-compiler paths rather 
than your host paths.

You should install this into your PATH so that configure scripts will 
detect it properly. Name it with a CTARGET prefix and the script will do 
the rest. In other words, if your CTARGET is set to arm-linux-uclibc, 
the canonical name is arm-linux-uclibc-pkg-config. Older configure 
scripts would only search for pkg-config, so in those cases you will 
need to export the PKG_CONFIG variable to the wrapper script.
^^^^^^^^^^^^^^

So, I created a file arm-softfloat-linux-gnueabi-pkg-config and placed 
same under my directory "/usr/arm-softfloat-linux-gnueabi/etc".  The 
contents of the file were copied form the web page, to wit:

vvvvvvvvvvvvvvv

#!/bin/sh
CTARGET=${0%-pkg-config}
SYSROOT="/usr/${CTARGET}"
export PKG_CONFIG_LIBDIR="${SYSROOT}/usr/lib/pkgconfig"
unset PKG_CONFIG_PATH PKG_CONFIG_ALLOW_SYSTEM_CFLAGS 
PKG_CONFIG_ALLOW_SYSTEM_LIBS
exec pkg-config "$@"


^^^^^^^^^^^^^^^
What I am not understanding is the instruction "install this into your 
PATH".  My current PATH is:

hermes etc # echo $PATH
/sbin:/bin:/usr/sbin:/usr/bin
hermes etc #

  
For the time that I would be cross-compiling and/or setting up this tool 
chain, should I add the directory where this file is to my path as in:

   hermes etc # export PATH=$PATH:/usr/arm-softfloat-linux-gnueabi/etc

or include the file directory in my path (as in a Java Jar)

  hermes etc # export 
PATH=$PATH:/usr/arm-softfloat-linux-gnueabi/etc/arm-softfloat-linux-gnueabi-pkg-config 


What brings me to you is that the emerge of sys-apps/coreutils-7.1 
failed, and it looks like a directory/location issue; here is the error 
message:

vvvvvvvvvvvvv
* The specific snippet of code:
*           mv ${fhs} ../../bin/ || die "could not move fhs bins";
*  The die message:
*   could not move fhs bins
^^^^^^^^^^^
The ebuild section the die statement comes from is:

vvvvvvvvvvvvvvvvvv
src_install() {
       emake install DESTDIR="${D}" || die
       dodoc AUTHORS ChangeLog* NEWS README* THANKS TODO

       insinto /etc
       newins src/dircolors.hin DIR_COLORS || die

       if [[ ${USERLAND} == "GNU" ]] ; then
               cd "${D}"/usr/bin
               dodir /bin
               # move critical binaries into /bin (required by FHS)
               local fhs="cat chgrp chmod chown cp date dd df echo false 
ln ls
                          mkdir mknod mv pwd rm rmdir stty sync true uname"
               mv ${fhs} ../../bin/ || die "could not move fhs bins"
               # move critical binaries into /bin (common scripts)
               local com="basename chroot cut dir dirname du env expr 
head mkfifo
                          mktemp readlink seq sleep sort tail touch tr 
tty vdir wc yes"
               mv ${com} ../../bin/ || die "could not move common bins"
               # create a symlink for uname in /usr/bin/ since autotools 
require it
               local x
               for x in ${com} uname ; do
                       dosym /bin/${x} /usr/bin/${x} || die
               done
       else
               # For now, drop the man pages, collides with the ones of 
the system.
               rm -rf "${D}"/usr/share/man
       fi
}

^^^^^^^^^^^^^^^^^^

I'm guessing I do not have my environment set correctly and I have not 
harnessed the functionality of the helping pkg-config script.

Note, the word "PATH", as capitalized, appears for the first time in 
section 5.e, so I'm guessing it has a special meaning or is referencing 
the environmental variable "PATH"?

I also made a copy of arm-softfloat-linux-gnueabi-pkg-config under the 
SYSROOT directory of "/usr/arm-softfloat-linux-gnueabi", that didn't 
change the die outcome of a sysapps/coreutils-7.1 emerge.

Where do I place the file arm-softfloat-linux-gnueabi-pkg-config and how 
should an addition to my PATH variable read?

Thank you for your time.

John Poole


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Re: [gentoo-embedded] Clarification of 5.e Embedded Handbook

[Сергей Миронов]

2009/6/7 John Poole <jlpoole@pon.net>:
> I'm trying to install a cross compiler on my AMD64 for arm (SheevaPlug) and
> have been following your Gentoo Embedded Handbook at
> http://www.gentoo.org/proj/en/base/embedded/handbook/index.xml
>
> I do not fully understand Chapter 5 "Cross-Compiling with Portage",
> specifically the section 5.e on "Helper: pkg-config".
>
> The instructions state:
>
> vvvvvvvvvvvv
>
> Many packages are moving to installing pkg-config files (*.pc) and using
> those to discover needed libraries and includes. To ease the build process,
> you should install a pkg-config wrapper for your target which will tell
> pkg-config to only search your cross-compiler paths rather than your host
> paths.
>
> You should install this into your PATH so that configure scripts will detect
> it properly. Name it with a CTARGET prefix and the script will do the rest.
> In other words, if your CTARGET is set to arm-linux-uclibc, the canonical
> name is arm-linux-uclibc-pkg-config. Older configure scripts would only
> search for pkg-config, so in those cases you will need to export the
> PKG_CONFIG variable to the wrapper script.
> ^^^^^^^^^^^^^^
>
> So, I created a file arm-softfloat-linux-gnueabi-pkg-config and placed same
> under my directory "/usr/arm-softfloat-linux-gnueabi/etc".  The contents of
> the file were copied form the web page, to wit:
>
> vvvvvvvvvvvvvvv
>
> #!/bin/sh
> CTARGET=${0%-pkg-config}
> SYSROOT="/usr/${CTARGET}"
> export PKG_CONFIG_LIBDIR="${SYSROOT}/usr/lib/pkgconfig"
> unset PKG_CONFIG_PATH PKG_CONFIG_ALLOW_SYSTEM_CFLAGS
> PKG_CONFIG_ALLOW_SYSTEM_LIBS
> exec pkg-config "$@"
>
>
> ^^^^^^^^^^^^^^^
> What I am not understanding is the instruction "install this into your
> PATH".  My current PATH is:
>
> hermes etc # echo $PATH
> /sbin:/bin:/usr/sbin:/usr/bin
> hermes etc #
>
>  For the time that I would be cross-compiling and/or setting up this tool
> chain, should I add the directory where this file is to my path as in:
>
>  hermes etc # export PATH=$PATH:/usr/arm-softfloat-linux-gnueabi/etc
>
> or include the file directory in my path (as in a Java Jar)
>
>  hermes etc # export
> PATH=$PATH:/usr/arm-softfloat-linux-gnueabi/etc/arm-softfloat-linux-gnueabi-pkg-config
>
> What brings me to you is that the emerge of sys-apps/coreutils-7.1 failed,
> and it looks like a directory/location issue; here is the error message:
>
> vvvvvvvvvvvvv
> * The specific snippet of code:
> *           mv ${fhs} ../../bin/ || die "could not move fhs bins";
> *  The die message:
> *   could not move fhs bins
> ^^^^^^^^^^^
> The ebuild section the die statement comes from is:
>
> vvvvvvvvvvvvvvvvvv
> src_install() {
>      emake install DESTDIR="${D}" || die
>      dodoc AUTHORS ChangeLog* NEWS README* THANKS TODO
>
>      insinto /etc
>      newins src/dircolors.hin DIR_COLORS || die
>
>      if [[ ${USERLAND} == "GNU" ]] ; then
>              cd "${D}"/usr/bin
>              dodir /bin
>              # move critical binaries into /bin (required by FHS)
>              local fhs="cat chgrp chmod chown cp date dd df echo false ln ls
>                         mkdir mknod mv pwd rm rmdir stty sync true uname"
>              mv ${fhs} ../../bin/ || die "could not move fhs bins"
>              # move critical binaries into /bin (common scripts)
>              local com="basename chroot cut dir dirname du env expr head
> mkfifo
>                         mktemp readlink seq sleep sort tail touch tr tty
> vdir wc yes"
>              mv ${com} ../../bin/ || die "could not move common bins"
>              # create a symlink for uname in /usr/bin/ since autotools
> require it
>              local x
>              for x in ${com} uname ; do
>                      dosym /bin/${x} /usr/bin/${x} || die
>              done
>      else
>              # For now, drop the man pages, collides with the ones of the
> system.
>              rm -rf "${D}"/usr/share/man
>      fi
> }
>
> ^^^^^^^^^^^^^^^^^^
>
> I'm guessing I do not have my environment set correctly and I have not
> harnessed the functionality of the helping pkg-config script.
>
> Note, the word "PATH", as capitalized, appears for the first time in section
> 5.e, so I'm guessing it has a special meaning or is referencing the
> environmental variable "PATH"?
>
> I also made a copy of arm-softfloat-linux-gnueabi-pkg-config under the
> SYSROOT directory of "/usr/arm-softfloat-linux-gnueabi", that didn't change
> the die outcome of a sysapps/coreutils-7.1 emerge.
>
> Where do I place the file arm-softfloat-linux-gnueabi-pkg-config and how
> should an addition to my PATH variable read?
>
> Thank you for your time.
>
> John Poole
>
>

Hmm, i used to save this script into my host system's
/usr/local/bin/arm-softfloat-linux-gnueabi, BUT

It seems, that Gentoo Embedded habdbook is quite old, and now there is
now need to write xmerge and friends by hand.
There is nasty libtool bug during crosscompiling and handbook says
nothing about it.
Use emerge crossdev-wrappers.

All steps are described here quite well:
http://gentoo.mindzoo.de/index.cgi/wiki/cross-compiling

-- 
Thanks
Sergey.