docs/README-raspberrypi.md
changeset 9025 d09d4b578e77
parent 9023 276802355854
child 9066 c2af3ff967cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docs/README-raspberrypi.md	Tue Jul 29 08:04:15 2014 -0700
@@ -0,0 +1,160 @@
+Raspberry Pi
+================================================================================
+
+Requirements:
+
+Raspbian (other Linux distros may work as well).
+
+================================================================================
+ Features
+================================================================================
+
+* Works without X11
+* Hardware accelerated OpenGL ES 2.x
+* Sound via ALSA
+* Input (mouse/keyboard/joystick) via EVDEV
+* Hotplugging of input devices via UDEV
+
+================================================================================
+ Raspbian Build Dependencies
+================================================================================
+
+sudo apt-get install libudev-dev libasound2-dev libdbus-1-dev
+
+You also need the VideoCore binary stuff that ships in /opt/vc for EGL and 
+OpenGL ES 2.x, it usually comes pre installed, but in any case:
+    
+sudo apt-get install libraspberrypi0 libraspberrypi-bin libraspberrypi-dev
+
+================================================================================
+ Cross compiling from x86 Linux
+================================================================================
+
+To cross compile SDL for Raspbian from your desktop machine, you'll need a
+Raspbian system root and the cross compilation tools. We'll assume these tools
+will be placed in /opt/rpi-tools
+
+    sudo git clone --depth 1 https://github.com/raspberrypi/tools /opt/rpi-tools
+
+You'll also need a Rasbian binary image.
+Get it from: http://downloads.raspberrypi.org/raspbian_latest 
+After unzipping, you'll get file with a name like: <date>-wheezy-raspbian.img
+Let's assume the sysroot will be built in /opt/rpi-sysroot.
+
+    export SYSROOT=/opt/rpi-sysroot
+    sudo kpartx -a -v <path_to_raspbian_image>.img
+    sudo mount -o loop /dev/mapper/loop0p2 /mnt
+    sudo cp -r /mnt $SYSROOT
+    sudo apt-get install qemu binfmt-support qemu-user-static
+    sudo cp /usr/bin/qemu-arm-static $SYSROOT/usr/bin
+    sudo mount --bind /dev $SYSROOT/dev
+    sudo mount --bind /proc $SYSROOT/proc
+    sudo mount --bind /sys $SYSROOT/sys
+
+Now, before chrooting into the ARM sysroot, you'll need to apply a workaround,
+edit $SYSROOT/etc/ld.so.preload and comment out all lines in it.
+
+    sudo chroot $SYSROOT
+    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
+    exit
+    sudo umount $SYSROOT/dev
+    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 $SYSROOT/usr/lib/arm-linux-gnueabihf/libdl.so
+
+The final step is compiling SDL itself.
+
+    export CC="/opt/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc --sysroot=$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"
+    cd <SDL SOURCE>
+    mkdir -p build;cd build
+    ../configure --with-sysroot=$SYSROOT --host=arm-raspberry-linux-gnueabihf --prefix=$PWD/rpi-sdl2-installed --disable-pulseaudio --disable-esd
+    make
+    make install
+
+To be able to deploy this to /usr/local in the Raspbian system you need to fix up a few paths:
+    
+    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
+    
+================================================================================
+ Apps don't work or poor video/audio performance
+================================================================================
+
+If you get sound problems, buffer underruns, etc, run "sudo rpi-update" to 
+update the RPi's firmware. Note that doing so will fix these problems, but it
+will also render the CMA - Dynamic Memory Split functionality useless.
+
+Also, by default the Raspbian distro configures the GPU RAM at 64MB, this is too
+low in general, specially if a 1080p TV is hooked up.
+
+See here how to configure this setting: http://elinux.org/RPiconfig
+
+Using a fixed gpu_mem=128 is the best option (specially if you updated the 
+firmware, using CMA probably won't work, at least it's the current case).
+
+================================================================================
+ No input
+================================================================================
+
+Make sure you belong to the "input" group.
+
+    sudo usermod -aG input `whoami`
+
+================================================================================
+ No HDMI Audio
+================================================================================
+
+If you notice that ALSA works but there's no audio over HDMI, try adding:
+    
+    hdmi_drive=2
+    
+to your config.txt file and reboot.
+
+Reference: http://www.raspberrypi.org/phpBB3/viewtopic.php?t=5062
+
+================================================================================
+ Text Input API support
+================================================================================
+
+The Text Input API is supported, with translation of scan codes done via the
+kernel symbol tables. For this to work, SDL needs access to a valid console.
+If you notice there's no SDL_TEXTINPUT message being emitted, double check that
+your app has read access to one of the following:
+    
+* /proc/self/fd/0
+* /dev/tty
+* /dev/tty[0...6]
+* /dev/vc/0
+* /dev/console
+
+This is usually not a problem if you run from the physical terminal (as opposed
+to running from a pseudo terminal, such as via SSH). If running from a PTS, a 
+quick workaround is to run your app as root or add yourself to the tty group,
+then re login to the system.
+
+   sudo usermod -aG tty `whoami`
+    
+The keyboard layout used by SDL is the same as the one the kernel uses.
+To configure the layout on Raspbian:
+    
+    sudo dpkg-reconfigure keyboard-configuration
+    
+To configure the locale, which controls which keys are interpreted as letters,
+this determining the CAPS LOCK behavior:
+
+    sudo dpkg-reconfigure locales
+
+================================================================================
+ Notes
+================================================================================
+
+* When launching apps remotely (via SSH), SDL can prevent local keystrokes from
+  leaking into the console only if it has root privileges. Launching apps locally
+  does not suffer from this issue.
+  
+