From b2793a2ce2d84df536db13dc40fb145ed4dba6c3 Mon Sep 17 00:00:00 2001 From: Sam Lantinga Date: Tue, 14 Jan 2025 12:58:30 -0800 Subject: [PATCH] Removed obsolete Raspberry Pi documentation --- docs/README-raspberrypi.md | 188 ------------------------------------- 1 file changed, 188 deletions(-) delete mode 100644 docs/README-raspberrypi.md diff --git a/docs/README-raspberrypi.md b/docs/README-raspberrypi.md deleted file mode 100644 index ba34f47b1fea0..0000000000000 --- a/docs/README-raspberrypi.md +++ /dev/null @@ -1,188 +0,0 @@ -Raspberry Pi -============ - -Requirements: - -Raspberry Pi OS (other Linux distros may work as well). - -In modern times, the Raspberry Pi works mostly like any other Linux device: -for video, you can use X11, Wayland, or KMSDRM. For audio, you can use ALSA, -PulseAudio, or PipeWire, etc. OpenGL, OpenGL ES, and Vulkan are known to work. - -There is a video backend in SDL called "rpi" that uses a deprecated Broadcom -interface (named "dispmanx") to draw directly to the console without X11. -Newer Raspberry Pi OS releases don't support this (and work fine with our -"kmsdrm" backend for the same purposes, a standard Linux interface). Don't -panic if you can't use this backend, or CMake says it can't find libraries it -needs for this. - -SDL has, in past times, worked on the original Raspberry Pi and the RPi 2, but -these devices are no longer targets we actively test; if they broke, please -report bugs or send patches! - -The Raspberry Pi 3 and later (in 32-bit and 64-bit mode) are still known to -work well at the time of this writing. The Raspberry Pi Zero and Zero 2 are -also known to work well. - - -## Documentation Out Of Date - -The rest of this document is likely out of date; a lot has changed in recent -years in both SDL and the Raspberry Pi universe, and this document has not -been updated to reflect those details. Take the rest of this information with -a grain of salt! - - - -NEON ----- - -If your Pi has NEON support, make sure you add -mfpu=neon to your CFLAGS so -that SDL will select some otherwise-disabled highly-optimized code. The -original Pi and Pi Zero units don't have NEON; everything from the Pi2/PiZero2 -and later do. - - -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 Raspbian binary image. -Get it from: http://downloads.raspberrypi.org/raspbian_latest -After unzipping, you'll get file with a name like: "-wheezy-raspbian.img" -Let's assume the sysroot will be built in /opt/rpi-sysroot. - - export SYSROOT=/opt/rpi-sysroot - sudo kpartx -a -v .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 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 - mkdir -p build;cd build - LDFLAGS="-L$SYSROOT/opt/vc/lib" ../configure --with-sysroot=$SYSROOT --host=arm-raspberry-linux-gnueabihf --prefix=$PWD/rpi-sdl3-installed --disable-pulseaudio --disable-esd - make - make install - -To be able to deploy this to /usr/local in the Raspbian system you need to fix up a few paths: - - perl -w -pi -e "s#$PWD/rpi-sdl3-installed#/usr/local#g;" ./rpi-sdl3-installed/lib/libSDL3.la ./rpi-sdl3-installed/lib/pkgconfig/sdl3.pc - -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_EVENT_TEXT_INPUT 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 - - -OpenGL problems ---------------- - -If you have desktop OpenGL headers installed at build time in your RPi or cross -compilation environment, support for it will be built in. However, the chipset -does not actually have support for it, which causes issues in certain SDL apps -since the presence of OpenGL support supersedes the ES/ES2 variants. -The workaround is to disable OpenGL at configuration time: - - ./configure --disable-video-opengl - -Or if the application uses the Render functions, you can use the SDL_RENDER_DRIVER -environment variable: - - export SDL_RENDER_DRIVER=opengles2 - -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. - -