meta-raspberrypi/docs/extra-build-config.md

1 # Optional build configuration
4 the build. We list here the ones that are closely related to this BSP or
6 <http://www.yoctoproject.org/docs/latest/ref-manual/ref-manual.html>
21   GPU. ARM gets the remaining memory. Min 16. Default 64.
24   the 512MB RP. Overrides gpu_mem. Max 192. Default not set.
27   the 256MB RP. Overrides gpu_mem. Max 448. Default not set.
30   the 256MB/512MB RP. Overrides gpu_mem. Max 944. Default not set.
32 See: <https://www.raspberrypi.com/documentation/computers/config_txt.html#memory-options>
36 …default, each machine uses `vc4` for graphics. This will in turn sets mesa as provider for `gl` li…
50 See: <https://www.raspberrypi.com/documentation/computers/config_txt.html#licence-key-and-codec-opt…
54 By default the GPU adds a black border around the video output to compensate for
62 By default a rainbow splash screen is shown after the GPU firmware is loaded.
70 before loading the kernel. By default it is one second. This is useful if your
80 By default SD card media is used as boot media.
84 The default value of `CMDLINE_ROOT_PARTITION` is "/dev/mmcblk0p2" to mount SD card. If you want to …
85 …b`. The "mmc" is required to load an image from the SD card, following the u-boot specification. S…
108 See: <https://www.raspberrypi.com/documentation/computers/config_txt.html#overclocking-options>
113 By default the video mode for these is autodetected on boot: the HDMI mode is
125 See: <https://www.raspberrypi.com/documentation/computers/configuration.html#hdmi-configuration>
140 This will enable the firmware to fall back to off-line compositing of Dispmanx
141 elements. Normally the compositing is done on-line, during scanout, but cannot
142 handle too many elements. With off-line enabled, an off-screen buffer is
144 of elements) is high, compositing will happen off-line into the buffer.
163 ## Boot to U-Boot
165 To have u-boot load kernel image, set in your local.conf:
169 This will select the appropriate image format for use with u-boot automatically.
171 be overridden to select the exact kernel image type (eg. zImage) and u-boot
174 To operate correctly, U-Boot requires `enable_uart=1` in `config.txt` file for
177 * Raspberry Pi 3 32-bit
178 * Raspberry Pi 3 64-bit
179 * Raspberry Pi 4 32-bit
180 * Raspberry Pi 4 64-bit
187 To build an initramfs image:
189 * Set this 3 kernel variables (in kernel's do_configure:prepend in linux-raspberrypi.inc after the …
191   - kernel_configure_variable BLK_DEV_INITRD y
192   - kernel_configure_variable INITRAMFS_SOURCE ""
193   - kernel_configure_variable RD_GZIP y
196   - `INITRAMFS_IMAGE = "<name for your initramfs image>"`
197   - `INITRAMFS_IMAGE_BUNDLE = "1"`
198   - `BOOT_SPACE = "1073741"`
199   - `INITRAMFS_MAXSIZE = "315400"`
200   - `IMAGE_FSTYPES:pn-${INITRAMFS_IMAGE} = "${INITRAMFS_FSTYPES}"`
206 partition or from the build image deploy directory.
209 FATPAYLOAD is a simple space-separated list of files to be copied:
214 listed in the DEPLOYPAYLOAD as a space-separated list of entries.
218     DEPLOYPAYLOAD = "example1-${MACHINE}:example1 example2"
239 Furthermore, to auto-load I2C kernel modules set:
241     KERNEL_MODULE_AUTOLOAD:rpi += "i2c-dev i2c-bcm2708"
249   - This will enable SPI bus and i2c device-trees, it will also setup
252 NOTE: To get this working the overlay for the PiTFT model must be build, added
255 Below is a list of currently supported PiTFT models in meta-raspberrypi, the
269 Screen LCD, HDMI interface (<http://www.waveshare.com/7inch-HDMI-LCD-C.htm>) Rev
276 RaspberryPi 0, 1, 2 and CM will have UART console enabled by default.
278 RaspberryPi 0 WiFi and 3 does not have the UART enabled by default because this
280 operations - 60fps h264 decode, high quality deinterlace - which aren't
289 * <https://github.com/RPi-Distro/repo/issues/22>
301 By default in case of the Compute Module 4 IO Board the standard USB driver
303 Users who want to use the 2 USB built-in ports or the other ports provided via
310 By default Linux will use all available CPUs for scheduling tasks. For real time
316 separated list ("1,2"), a range("1-3"), or a mixture of these ("1,3-5")
318     ISOLATED_CPUS = "1-2"
326 See: <https://openlabs.co/OSHW/Raspberry-Pi-802.15.4-radio>
330 In order to use CAN with an MCP2515-based module, set the following variables:
340 …board. The frequency is usually marked on the package of the crystal. By default, it is set to 16 …
344 Configure the interrupt pin to the one connected to the CAN module. By default,
353 * PiCAN2 (16 MHz crystal): <http://skpang.co.uk/catalog/pican2-canbus-board-for-raspberry-pi-23-p-1…
354 * WaveShare RS485 CAN HAT (8 MHz or 12 MHz crystal): <https://www.waveshare.com/rs485-can-hat.htm>
355 …uo (16 MHz crystal): <http://skpang.co.uk/catalog/pican2-duo-canbus-board-for-raspberry-pi-23-p-14…
364 This will add device tree overlays gpio-ir and gpio-ir-tx to config.txt.
365 Appropriate kernel modules will be also included in the image. By default the
366 GPIO pin for gpio-ir is set to 18 and the pin for gpio-ir-tx is 17. Both pins
369 ## Enable gpio-shutdown
371 When using device tree kernels, set this variable to enable gpio-shutdown:
376 the gpio-keys kernel module in the image. If System V init is used, additional
380 By default the feature uses gpio pin 3 (except RPi 1 Model B rev 1 enumerates
387 ## Enable One-Wire Interface
389 One-wire is a single-wire communication bus typically used to connect sensors
390 to the RaspberryPi. The Raspberry Pi supports one-wire on any GPIO pin, but
391 the default is GPIO 4. To enable the one-wire interface explicitly set it in
396 Once discovery is complete you can list the devices that your Raspberry Pi has
397 discovered via all 1-Wire busses check the interface with this command
399 `ls /sys/bus/w1/devices/`
406 If double-quotes are needed in the lines you are adding you can use single
409 For example, to add a comment containing a double-quote and a configuration
418 Raspberry Pi does not have the unicam device ( Raspberry Pi Camera ) enabled by default.
419 Because this unicam device ( bcm2835-unicam ) as of now is used by libcamera opensource.
437 * <https://www.raspberrypi.org/blog/an-open-source-camera-stack-for-raspberry-pi-using-libcamera/>
441 Support for WM8960 based sound cards such as the WM8960 Hi-Fi Sound Card HAT for Raspberry Pi from …
445 You may need to adjust volume and toggle switches that are off by default
447     amixer -c1 sset 'Headphone',0 80%,80%
448     amixer -c1 sset 'Speaker',0 80%,80%
449     amixer -c1 sset 'Left Input Mixer Boost' toggle
450     amixer -c1 sset 'Left Output Mixer PCM' toggle
451     amixer -c1 sset 'Right Input Mixer Boost' toggle
452     amixer -c1 sset 'Right Output Mixer PCM' toggle
456 ## Support for RTC devices
462 `rtc` is handled as a `MACHINE_FEATURES` in the context of the build system
473 included/configured in the build system based on the inclusion of `rtc` in
478 To enable Raspberry Pi Distro VLC, the `meta-openembedded/meta-multimedia` layer must be
481 VLC does not support HW accelerated video decode through MMAL on a 64-bit OS.
487 MMAL is not enabled by default. To enable it add
491 to `local.conf`. Adding `vlc` to `IMAGE_INSTALL` will then default to building the oe-core
492 implementation of ffmpeg and the meta-openembedded/meta-multimedia implementation of VLC.
496     PREFERRED_PROVIDER_vlc = "rpidistro-vlc"
497     PREFERRED_PROVIDER_ffmpeg = "rpidistro-ffmpeg"
498     PREFERRED_PROVIDER_libav = "rpidistro-ffmpeg"
499     PREFERRED_PROVIDER_libpostproc = "rpidistro-ffmpeg"
501 Usage example: Start VLC with mmal_vout plugin and without an active display server.
503     DISPLAYNUM=$(tvservice -l | tail -c 2)
505 … VLC_SETTINGS="-I dummy --vout=mmal_vout --mmal-resize --mmal-display hdmi-$MMAL_DISPLAY --no-dbus"