source: rtems/INSTALL @ 246e23c

Building RTEMS
==============
See the file README.configure.


UNCOMPRESSING .tgz FILES
===========================
Many of the files found in this directory and its subdirectories 
are gzip'ed, tar archive files.  These files have the ".tgz"
extension.  They were compressed with gzip version 1.2.4.  

Use a command sequence similar to the following to uncompress each
file:

   gzcat FILE.tgz | tar xvof -

where FILE.tgz is the file to be installed.  This procedure will
extract the files in the archive into the current directory.
All of the .tgz files associated with this release RTEMS will
place their contents in a subdirectory rtems-<release> in the current
directory.

If you are unsure of what is in an RTEMS archive file, then use
the following command sequence to get a listing of the contents:

   gzcat FILE.tgz | tar tvf -

NOTES:  

(1) The "-o" option to tar is included on the tar command line
    so that the user extracting the tar archive will own the extracted
    files.

(2) gzcat is sometimes installed as zcat.  Be warned that on many
    (most) UNIX machines, zcat is associated with compress (.Z files).

(3) If you do not have gzip 1.2.4, it is available from numerous sites
    including this one.  Other sites include ftp.gnu.org and ftp.cdrom.com.
    
(4) The GNU archive files included in this distribution are packaged
    exactly like they are on official GNU ftp sites.  When extracting
    GNU archives, they will not extract under a rtems-<version> 
    directory.  They will extract themselves under a directory which
    is the name and version of the tool in question.  For example,
    gcc-2.5.8.tgz will extract its contents into the subdirectory 
    gcc-2.5.8.