Fix Sim for newer distros

__builtin found fix for rbendian.h
tools/configure defines SIM_USE_BYTESWAP_H if byteswap.h is found in
/usr/include/ maybe there is a better mechanism for this

genshortcut.sh is a simple script to make .desktop shortcut files
several newer distros don't allow you to run the simulator from the
file manager, this or perhaps a different method can probably be
included while building a sim at a later date.

for now it can be run manually like so:
similar to ../tools/configure
run from your simulator folder
../tools/genshortcut.sh exepath shortname icon
ex. ../tools/genshortcut.sh ./rockboxui clip+sim music-app

Change-Id: Ia05d3a9349b27c5968a4a7a68b2eb480e60faec3

firmware/include/rbendian.h

@@ -23,6 +23,10 @@
 
 #include "config.h"
 
+#ifdef SIM_USE_BYTESWAP_H
+#include <byteswap.h>
+#endif
+
 #ifndef __MINGW32__
 #include <endian.h>
 #endif

tools/configure

@@ -10,6 +10,9 @@
 # global CC options for all platforms
 CCOPTS="-W -Wall -Wundef -O -nostdlib -ffreestanding -Wstrict-prototypes -pipe -std=gnu99"
 
+#newer versions GLIBC use byteswap.h
+BYTESWP="/usr/include/byteswap.h"
+
 # LD options for the core
 LDOPTS=""
 # LD options for the core + plugins
@@ -4471,6 +4474,10 @@ fi
 if [ "yes" = "$simulator" ]; then
     echo Unsetting APPLICATION define for SIMULATOR build
     unset application
+    if test -f "$BYTESWP"; then
+        echo Using "$BYTESWP"
+        extradefines="$extradefines -DSIM_USE_BYTESWAP_H=$BYTESWP"
+    fi
 fi
 
 if [ "yes" = "$application" ]; then

tools/genshortcut.sh

@@ -0,0 +1,41 @@
+#!/bin/sh
+#             __________               __   ___.
+#   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+#   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+#   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+#   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+#                     \/            \/     \/    \/            \/
+#
+#shortcut.desktop generator
+
+# Create a .desktop entry to allow the simulator to be executed in newer shells
+# $1 executable
+# $2 shortcut name
+# $3 icon
+create_shortcut() {
+    path="$(cd "$(dirname "$1")"; pwd)/"
+    execname=$(basename "$1")
+    shortname="$2"
+    icon="$3"
+    shortcut="$path$shortname.desktop"
+
+    echo "Creating shortcut $shortcut"
+    echo "path: $path"
+    echo "exec: $execname"
+    echo "icon: $icon"
+
+    echo "[Desktop Entry]
+    Encoding=UTF-8
+    Version=1.1
+    Type=Application
+    Categories=Apps;
+    Terminal=false
+    Name=$shortname
+    Path=$path
+    Exec=$path/$execname
+    Icon=$icon
+    Name[en-US]=$shortname" > $shortcut
+}
+
+#./genshortcut.sh ./rockboxui target-sim music-app
+create_shortcut $@