sdl

FORK: Simple Directmedia Layer
git clone https://git.neptards.moe/neptards/sdl.git
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README-raspberrypi.md (8051B)

      1 Raspberry Pi
      2 ================================================================================
      3 
      4 Requirements:
      5 
      6 Raspbian (other Linux distros may work as well).
      7 
      8 ================================================================================
      9  Features
     10 ================================================================================
     11 
     12 * Works without X11
     13 * Hardware accelerated OpenGL ES 2.x
     14 * Sound via ALSA
     15 * Input (mouse/keyboard/joystick) via EVDEV
     16 * Hotplugging of input devices via UDEV
     17 
     18 
     19 ================================================================================
     20  Raspbian Build Dependencies
     21 ================================================================================
     22 
     23 sudo apt-get install libudev-dev libasound2-dev libdbus-1-dev
     24 
     25 You also need the VideoCore binary stuff that ships in /opt/vc for EGL and 
     26 OpenGL ES 2.x, it usually comes pre-installed, but in any case:
     27     
     28 sudo apt-get install libraspberrypi0 libraspberrypi-bin libraspberrypi-dev
     29 
     30 
     31 ================================================================================
     32  NEON
     33 ================================================================================
     34 
     35 If your Pi has NEON support, make sure you add -mfpu=neon to your CFLAGS so
     36 that SDL will select some otherwise-disabled highly-optimized code. The
     37 original Pi units don't have NEON, the Pi2 probably does, and the Pi3
     38 definitely does.
     39 
     40 ================================================================================
     41  Cross compiling from x86 Linux
     42 ================================================================================
     43 
     44 To cross compile SDL for Raspbian from your desktop machine, you'll need a
     45 Raspbian system root and the cross compilation tools. We'll assume these tools
     46 will be placed in /opt/rpi-tools
     47 
     48     sudo git clone --depth 1 https://github.com/raspberrypi/tools /opt/rpi-tools
     49 
     50 You'll also need a Raspbian binary image.
     51 Get it from: http://downloads.raspberrypi.org/raspbian_latest 
     52 After unzipping, you'll get file with a name like: "<date>-wheezy-raspbian.img"
     53 Let's assume the sysroot will be built in /opt/rpi-sysroot.
     54 
     55     export SYSROOT=/opt/rpi-sysroot
     56     sudo kpartx -a -v <path_to_raspbian_image>.img
     57     sudo mount -o loop /dev/mapper/loop0p2 /mnt
     58     sudo cp -r /mnt $SYSROOT
     59     sudo apt-get install qemu binfmt-support qemu-user-static
     60     sudo cp /usr/bin/qemu-arm-static $SYSROOT/usr/bin
     61     sudo mount --bind /dev $SYSROOT/dev
     62     sudo mount --bind /proc $SYSROOT/proc
     63     sudo mount --bind /sys $SYSROOT/sys
     64 
     65 Now, before chrooting into the ARM sysroot, you'll need to apply a workaround,
     66 edit $SYSROOT/etc/ld.so.preload and comment out all lines in it.
     67 
     68     sudo chroot $SYSROOT
     69     apt-get install libudev-dev libasound2-dev libdbus-1-dev libraspberrypi0 libraspberrypi-bin libraspberrypi-dev libx11-dev libxext-dev libxrandr-dev libxcursor-dev libxi-dev libxinerama-dev libxxf86vm-dev libxss-dev
     70     exit
     71     sudo umount $SYSROOT/dev
     72     sudo umount $SYSROOT/proc
     73     sudo umount $SYSROOT/sys
     74     sudo umount /mnt
     75     
     76 There's one more fix required, as the libdl.so symlink uses an absolute path 
     77 which doesn't quite work in our setup.
     78 
     79     sudo rm -rf $SYSROOT/usr/lib/arm-linux-gnueabihf/libdl.so
     80     sudo ln -s ../../../lib/arm-linux-gnueabihf/libdl.so.2 $SYSROOT/usr/lib/arm-linux-gnueabihf/libdl.so
     81 
     82 The final step is compiling SDL itself.
     83 
     84     export CC="/opt/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc --sysroot=$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"
     85     cd <SDL SOURCE>
     86     mkdir -p build;cd build
     87     LDFLAGS="-L$SYSROOT/opt/vc/lib" ../configure --with-sysroot=$SYSROOT --host=arm-raspberry-linux-gnueabihf --prefix=$PWD/rpi-sdl2-installed --disable-pulseaudio --disable-esd
     88     make
     89     make install
     90 
     91 To be able to deploy this to /usr/local in the Raspbian system you need to fix up a few paths:
     92     
     93     perl -w -pi -e "s#$PWD/rpi-sdl2-installed#/usr/local#g;" ./rpi-sdl2-installed/lib/libSDL2.la ./rpi-sdl2-installed/lib/pkgconfig/sdl2.pc ./rpi-sdl2-installed/bin/sdl2-config
     94     
     95 ================================================================================
     96  Apps don't work or poor video/audio performance
     97 ================================================================================
     98 
     99 If you get sound problems, buffer underruns, etc, run "sudo rpi-update" to 
    100 update the RPi's firmware. Note that doing so will fix these problems, but it
    101 will also render the CMA - Dynamic Memory Split functionality useless.
    102 
    103 Also, by default the Raspbian distro configures the GPU RAM at 64MB, this is too
    104 low in general, specially if a 1080p TV is hooked up.
    105 
    106 See here how to configure this setting: http://elinux.org/RPiconfig
    107 
    108 Using a fixed gpu_mem=128 is the best option (specially if you updated the 
    109 firmware, using CMA probably won't work, at least it's the current case).
    110 
    111 ================================================================================
    112  No input
    113 ================================================================================
    114 
    115 Make sure you belong to the "input" group.
    116 
    117     sudo usermod -aG input `whoami`
    118 
    119 ================================================================================
    120  No HDMI Audio
    121 ================================================================================
    122 
    123 If you notice that ALSA works but there's no audio over HDMI, try adding:
    124     
    125     hdmi_drive=2
    126     
    127 to your config.txt file and reboot.
    128 
    129 Reference: http://www.raspberrypi.org/phpBB3/viewtopic.php?t=5062
    130 
    131 ================================================================================
    132  Text Input API support
    133 ================================================================================
    134 
    135 The Text Input API is supported, with translation of scan codes done via the
    136 kernel symbol tables. For this to work, SDL needs access to a valid console.
    137 If you notice there's no SDL_TEXTINPUT message being emitted, double check that
    138 your app has read access to one of the following:
    139     
    140 * /proc/self/fd/0
    141 * /dev/tty
    142 * /dev/tty[0...6]
    143 * /dev/vc/0
    144 * /dev/console
    145 
    146 This is usually not a problem if you run from the physical terminal (as opposed
    147 to running from a pseudo terminal, such as via SSH). If running from a PTS, a 
    148 quick workaround is to run your app as root or add yourself to the tty group,
    149 then re-login to the system.
    150 
    151     sudo usermod -aG tty `whoami`
    152     
    153 The keyboard layout used by SDL is the same as the one the kernel uses.
    154 To configure the layout on Raspbian:
    155     
    156     sudo dpkg-reconfigure keyboard-configuration
    157     
    158 To configure the locale, which controls which keys are interpreted as letters,
    159 this determining the CAPS LOCK behavior:
    160 
    161     sudo dpkg-reconfigure locales
    162 
    163 ================================================================================
    164  OpenGL problems
    165 ================================================================================
    166 
    167 If you have desktop OpenGL headers installed at build time in your RPi or cross 
    168 compilation environment, support for it will be built in. However, the chipset 
    169 does not actually have support for it, which causes issues in certain SDL apps 
    170 since the presence of OpenGL support supersedes the ES/ES2 variants.
    171 The workaround is to disable OpenGL at configuration time:
    172 
    173     ./configure --disable-video-opengl
    174 
    175 Or if the application uses the Render functions, you can use the SDL_RENDER_DRIVER
    176 environment variable:
    177 
    178     export SDL_RENDER_DRIVER=opengles2
    179 
    180 ================================================================================
    181  Notes
    182 ================================================================================
    183 
    184 * When launching apps remotely (via SSH), SDL can prevent local keystrokes from
    185   leaking into the console only if it has root privileges. Launching apps locally
    186   does not suffer from this issue.
    187   
    188