[PATCH v2] Allow building on Mac OS X

[Programmingkid]

This is version two of the patch that allows for building on Mac OS X. It addresses 
several issues that needed to be changed. This version has these changes:
- Keeps sh as the shell to build OpenBIOS on.
- Removed the prefix_specified() function.
- Replaced Bash shell code with awk functionality.
- Added error handling for missing -prefix and -arch values.
- Allows for using more that one compiler even if the -prefix option is used. 
- Keeps the -Werror option.

I would like to note that this patch has been tested on Debian Linux and 
Mac OS X.

Index: config/scripts/switch-arch
===================================================================
--- config/scripts/switch-arch	(revision 1334)
+++ config/scripts/switch-arch	(working copy)
@@ -6,7 +6,7 @@
 MOLPATH=$HOME/mol-0.9.71

if [ x"$1" = x -o "$1" = "-help" ]; then
-  printf "Usage:\n  $0 [arch-config]...\n"
+  printf "Usage:\n  $0 [arch-config] [-arch architecture] [-prefix compiler prefix]\n"
   printf "arch-config values supported for native or cross compiled builds:\n"
   printf " amd64, ppc, sparc32, sparc64, x86\n\n"
   printf "Add "unix-" prefix to compile openbios-unix executable (native only)\n"
@@ -13,7 +13,13 @@
   printf "Add "builtin-" prefix to compile openbios-builtin executables\n\n"
   printf "Without prefixes, builtin and unix targets are selected\n\n"
   printf "Special targets: mol-ppc briq-ppc pearpc-ppc qemu-ppc qemu-ppc64 xbox-x86\n\n"
-  printf "Example: $0 builtin-sparc32 unix-amd64 builtin-amd64\n"
+  printf "Example: $0 builtin-sparc32 unix-amd64 builtin-amd64\n\n"
+  printf "The -arch option is used if your uname command does not output the correct\n"
+  printf "value for your system. This is an issue for some versions of Mac OS X.\n"
+  printf "Example: -arch amd64\n\n"
+  printf "The -prefix option is for specifying your compiler prefix.\n"
+  printf "If your compiler is called ppc-elf-gcc, then your prefix would be ppc-elf-\n"
+  printf "In this case you would use -prefix ppc-elf-\n\n"
   exit 0
 fi

@@ -89,17 +95,77 @@
     CROSSCFLAGS=$cflags
 }

+
+## Determines if user specified an architecture ##
+architecture_specified()
+{
+    for arg in $SCRIPT_ARGS
+    do
+        if [ "$arg" = "-arch" ]
+        then
+            return 1
+        fi
+    done
+    return 0
+}
+
+## Returns the user specified architecture ##
+get_specified_architecture()
+{
+    while [ "$1" != "" ]
+    do
+        if [ "$1" = "-arch" ]
+        then
+            shift
+            if [ "$1" ]
+            then
+                echo "$1"
+            else
+                echo "ERROR-MISSING-ARCHITECTURE!!!"
+            fi
+            return
+        fi
+        shift
+    done
+}
+
 archname()
 {
-    HOSTARCH=`uname -m | sed -e s/i.86/x86/ -e s/i86pc/x86/ \
-	-e s/sun4u/sparc64/ -e s/sparc$/sparc32/ \
-	-e s/arm.*/arm/ -e s/sa110/arm/ -e s/x86_64/amd64/ \
-	-e "s/Power Macintosh/ppc/"`
+    architecture_specified $SCRIPT_ARGS
+    if [ "$?" -eq 1 ]
+    then
+        HOSTARCH=`get_specified_architecture $SCRIPT_ARGS`
+    else
+        HOSTARCH=`uname -m | sed -e s/i.86/x86/ -e s/i86pc/x86/ \
+        -e s/sun4u/sparc64/ -e s/sparc$/sparc32/ \
+        -e s/arm.*/arm/ -e s/sa110/arm/ -e s/x86_64/amd64/ \
+        -e "s/Power Macintosh/ppc/"`
+    fi
 }

+## Returns the user specified compiler prefix ##
+get_specified_prefix()
+{
+    while [ "$1" != "" ]
+    do
+        if [ "$1" = "-prefix" ]
+        then
+            shift
+            if [ "$1" ]
+            then
+                echo "$1"
+            else
+                echo "MISSING-PREFIX-VALUE!!!"
+            fi
+            return
+        fi
+        shift
+    done
+}
+
 select_prefix()
 {
-    for TARGET in ${1}-unknown-linux-gnu- ${1}-linux-gnu- ${1}-linux- ${1}-elf- ${1}-eabi-
+    for TARGET in ${1}-unknown-linux-gnu- ${1}-linux-gnu- ${1}-linux- ${1}-elf- ${1}-eabi- $(get_specified_prefix $SCRIPT_ARGS)
     do
         if type ${TARGET}gcc > /dev/null 2>&1
         then
@@ -127,6 +193,7 @@

SRCDIR=`dirname "$0"`/../..
 BUILDDIR=`pwd`
+SCRIPT_ARGS=$*  # needed for functions that need to know arguments send to this script

# make source path absolute
 SRCDIR=`cd "$SRCDIR"; pwd`
@@ -147,7 +214,34 @@
 fi

target_list=""
-for target in $*; do
+
+# filters out the -prefix and -arch options from the target list
+filtered_list=`awk -v arg_string="$*" 'BEGIN { 
+    prefix_position = index(arg_string, "-prefix")
+    arch_position = index(arg_string, "-arch")
+    end = 0 # The end of the target list string before the other options
+    
+    ### Find the end of the substring to keep ###
+    
+    if(prefix_position == 0 && arch_position == 0) {
+        end = length(arg_string)
+    }
+    else if(prefix_position == 0) {
+        end = (arch_position - 1)
+    }
+    else if (arch_position == 0) {
+        end = (prefix_position - 1)
+    }
+    else if(arch_position < prefix_position) {
+        end = (arch_position - 1)
+    }
+    else {
+        end = (prefix_position - 1)
+    }
+    print substr(arg_string, 1, end)
+}'`
+
+for target in $filtered_list; do
     case $target in
         unix-*|builtin-*|plain-*|mol-ppc|briq-ppc|pearpc-ppc|qemu-ppc|qemu-ppc64|xbox-x86)
         target_list="$target_list $target"