From mboxrd@z Thu Jan  1 00:00:00 1970
From: Grant Edwards <grante@visi.com>
To: Atsumi Hirose <atsumi99@yahoo.com>
Cc: ecos-discuss@sourceware.cygnus.com
Subject: Re: [ECOS] building gcc-2.95.1 for eCos 1.2.1
Date: Thu, 04 Nov 1999 10:21:00 -0000
Message-id: <19991104122146.A24204@visi.com>
References: <19991104031007.12225.rocketmail@web1706.mail.yahoo.com> <19991104084420.A14088@visi.com>
X-SW-Source: 1999-11/msg00012.html

I previously wrote:

> One of the things I'm going to do during the next few days is try to
> repeat the build process I used and document exactly what I had to do
> to get gcc to build.

Here's a link with a lot of useful information:

                   http://www.objsw.com/CrossGCC/

Some of it is specific to older versions of gcc, but much of it is still useful.

Building a cross-compiler for an embedded system isn't quite as bad as it seemed 
the first time through the process.  The steps I used to build an ARM compiler on
my Linux (RH6.0) system are:


 1) Build and install gdb.

    Follow the standard instructions after configuring with 
               --target=arm-elf --program-prefix=arm-elf-

    That should result in a program named arm-elf-gdb being installed in
    /usr/local/bin.


 2) Build and install binutils.

    Follow the standard instructions after configuring with
               --target=arm-elf --program-prefix=arm-elf-

    That should result in programs named arm-elf-as, arm-elf-ld, etc. installed
    in /usr/local/bin.


At this point you should be able to assemble and link a program.  You
should be able to load the program into your target and run it with
gdb.  If not, then building gcc isn't going to be of much use. ;)
 
 3) Build and install a gcc cross compiler.

    a) Configure with --target=arm-elf --program-prefix=arm-elf-

    b) The build process for libgcc will try to use an assembler at
       /usr/local/arm-elf/bin/as.  

       Make that a symbolic link to /usr/local/bin/arm-elf-as.

    c) Do "make all-gcc"  

       This should build the compiler itself and libgcc.a.  

       If you just do a "make", it will try to build a wagon-load of stuff
       that will fail: libio, libg++, whatever.

    d) Do "make install-gcc"

       This should install the compiler shell as
       /usr/local/bin/arm-elf-gcc and the rest of the stuff under
       /usr/local/lib/gcc-lib/arm-elf/2.95.1.

At this point you should be able to compile a program with arm-elf-gcc.

NB: The default output from ARM targeted tools is little-endian.  Therefore,
    the libgcc.a created by step 3c) is little-endian.  I had to
    rebuild mine since I have big-endian hardware.  Next, I'll try to
    document the easiest way to do that.

-- 
Grant Edwards
grante@visi.com