Building for raspberry pi 4

[lelecanfora]

Hi, thanks for the great work! I am trying to compile on the rpi4 but it breaks, using this version fa55ddc

lele@raspberrypi:~/mupen64plus-libretro-nx $ CFLAGS="platform=rpi4" CXXFLAGS="$CFLAGS" make mupen64plus_next_libretro.so
cc  platform=rpi4 -std=gnu11 -D_CRT_SECURE_NO_WARNINGS -Wno-discarded-qualifiers -O3 -DNDEBUG -fsigned-char -ffast-math -fno-strict-aliasing -fomit-frame-pointer -fvisibility=hidden -fcommon -DGIT_VERSION=\"" fa55ddc"\" -DOS_LINUX -I./mupen64plus-core/subprojects/md5 -D__STDC_CONSTANT_MACROS -D__STDC_LIMIT_MACROS -D__LIBRETRO__ -DUSE_FILE32API -DM64P_PLUGIN_API -DM64P_CORE_PROTOTYPES -D_ENDUSER_RELEASE -DSINC_LOWER_QUALITY -DTXFILTER_LIB -D__VEC4_OPT -DMUPENPLUSAPI -I./custom -I./custom/mupen64plus-core -I./custom/android/include -I./custom/GLideN64 -I./GLideN64/src -I./GLideN64/src/osal -I./mupen64plus-core/src -I./mupen64plus-core/src/api -I./custom/mupen64plus-core/plugin/audio_libretro -I./libretro-common/include -I./libretro -I./GLideN64/src/inc -I./custom/dependencies/libpng -I./mupen64plus-core/subprojects/minizip -I./xxHash -I./custom/dependencies/libzlib  -fPIC  -DCORE -DHAVE_OPENGL -DNEW_DYNAREC=4 -DDYNAREC -I./mupen64plus-core/src/asm_defines/ -c mupen64plus-core/src/api/callbacks.c -o mupen64plus-core/src/api/callbacks.o
cc: warning: platform=rpi4: linker input file unused because linking not done
cc: error: platform=rpi4: linker input file not found: No such file or directory
make: *** [Makefile:670: mupen64plus-core/src/api/callbacks.o] Error 1

what are the flags to compile with all the graphical libraries?