[PATCH modular 3/4] build.sh: comment the supported systems and how they are detected

[Gaetan Nadon]

For many, build.sh is the first encounter to X.Org or even UNIX code.
This comment should help them understand why certain packages cannot be
built on thier system.

Signed-off-by: Gaetan Nadon <memsize at videotron.ca>
---
 build.sh |   29 +++++++++++++++++++++++++++--
 1 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/build.sh b/build.sh
index 2490fb2..cfbddba 100755
--- a/build.sh
+++ b/build.sh
@@ -1,10 +1,35 @@
 #!/bin/sh
-#
-# Note on portability:
+
+# Script Portability
 # This script is intended to run on any platform supported by X.Org.
 # The Autoconf generated configure script is a good reference as to what is permitted.
 # Basically, it should be able to run in a Bourne shell.
 
+# Supported System Exceptions
+# Not all packages can be built on all systems. Some useful values from config.guess:
+# uname -s   Description, as it relates to X.Org supported systems
+# --------   --------------------------------------------------------------------------
+# CYGWIN*    a Unix-like environment and command-line interface for Microsoft Windows
+# Darwin     an open source operating system released by Apple Inc. in 2000
+# Dragonfly  a Unix-like operating system created as a fork of FreeBSD 4.8
+# FreeBSD    a free Unix-like operating system descended from AT&T UNIX via BSD UNIX
+# Linux      a Unix-like operating systems with GNU software and Linux kernel
+# GNU        a Unix-like operating system developed by the GNU project - Hurd microkernel
+# GNU/*      a Unix-like operating system with GNU software but a non Linux kernel
+# NetBSD     an open source version of the Unix-derivative Berkeley Software Distribution
+# OpenBSD    a Unix-like operating system descended from Berkeley Software Distribution
+# SunOS      a version of the Unix operating system developed by Sun Microsystems
+#
+# Not all packages can be built on all cpus. Some useful values from config.guess:
+# uname -m   Description, as it relates to X.Org supported cpus
+# --------   --------------------------------------------------------------------------
+# i*86       a familly of 32-bit Intel/AMD microprocessors
+# x86_64     a familly of 64-bit Intel/AMD microprocessors
+# amd64      a CYGWIN designation for x86_64 microprocessors
+# sparc      a RISC instruction set architecture (ISA) developed by Sun Microsystems
+# sparc64    a RISC instruction set architecture (ISA) developed by Sun Microsystems
+
+
 envoptions() {
 cat << EOF
 Environment variables specific to build.sh:
-- 
1.6.0.4