Fixes building for RPi using --no-undefined

README-raspberrypi.txt

@@ -62,6 +62,12 @@ edit $SYSROOT/etc/ld.so.preload and comment out all lines in it.
     sudo umount $SYSROOT/proc
     sudo umount $SYSROOT/sys
     sudo umount /mnt
+    
+There's one more fix required, as the libdl.so symlink uses an absolute path 
+which doesn't quite work in our setup.
+
+    sudo rm -rf $SYSROOT/usr/lib/arm-linux-gnueabihf/libdl.so
+    sudo ln -s ../../../lib/arm-linux-gnueabihf/libdl.so.2 $SYSROOT/usr/lib/arm-linux-gnueabihf/libdl.so
 
 The final step is compiling SDL itself.
 

build-scripts/raspberrypi-buildbot.sh

@@ -39,7 +39,7 @@ mkdir -p $BUILDBOTDIR
 pushd $BUILDBOTDIR
 
 SYSROOT="/opt/rpi-sysroot"
-export CC="/opt/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc --sysroot=$SYSROOT -I$SYSROOT/opt/vc/include -I$SYSROOT/usr/include -I$SYSROOT/opt/vc/include/interface/vcos/pthreads -I$SYSROOT/opt/vc/include/interface/vmcs_host/linux"
+export CC="/opt/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc --sysroot=$SYSROOT -I$SYSROOT/opt/vc/include -I$SYSROOT/usr/include -I$SYSROOT/opt/vc/include/interface/vcos/pthreads -I$SYSROOT/opt/vc/include/interface/vmcs_host/linux -L$SYSROOT/opt/vc/lib"
 # -L$SYSROOT/usr/lib/arm-linux-gnueabihf"
 # !!! FIXME: shouldn't have to --disable-* things here.
 ../configure --with-sysroot=$SYSROOT --host=arm-raspberry-linux-gnueabihf --prefix=$PWD/rpi-sdl2-installed --disable-pulseaudio --disable-esd

configure

@@ -22102,11 +22102,10 @@ case "$host" in
                 # Raspberry Pi
                 ARCH=linux
                 RPI_CFLAGS="-I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux"
-                RPI_LDFLAGS="-L/opt/vc/lib -lbcm_host"
                 CFLAGS="$CFLAGS $RPI_CFLAGS"
                 SDL_CFLAGS="$SDL_CFLAGS $RPI_CFLAGS"
                 EXTRA_CFLAGS="$EXTRA_CFLAGS $RPI_CFLAGS"
-                SDL_LIBS="$SDL_LIBS $RPI_LDFLAGS"
+                EXTRA_LDFLAGS="$EXTRA_LDFLAGS -L/opt/vc/lib -lbcm_host -ldl"
 
                 if test x$enable_video = xyes; then
                     SOURCES="$SOURCES $srcdir/src/video/raspberry/*.c"

configure.in

@@ -2384,11 +2384,10 @@ case "$host" in
                 # Raspberry Pi
                 ARCH=linux
                 RPI_CFLAGS="-I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux"
-                RPI_LDFLAGS="-L/opt/vc/lib -lbcm_host"
                 CFLAGS="$CFLAGS $RPI_CFLAGS"
                 SDL_CFLAGS="$SDL_CFLAGS $RPI_CFLAGS"
                 EXTRA_CFLAGS="$EXTRA_CFLAGS $RPI_CFLAGS"
-                SDL_LIBS="$SDL_LIBS $RPI_LDFLAGS"
+                EXTRA_LDFLAGS="$EXTRA_LDFLAGS -L/opt/vc/lib -lbcm_host -ldl"
 
                 if test x$enable_video = xyes; then
                     SOURCES="$SOURCES $srcdir/src/video/raspberry/*.c"