diff options
Diffstat (limited to 'meta-raspberrypi/docs/extra-build-config.md')
| -rw-r--r-- | meta-raspberrypi/docs/extra-build-config.md | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/meta-raspberrypi/docs/extra-build-config.md b/meta-raspberrypi/docs/extra-build-config.md new file mode 100644 index 0000000000..806c238036 --- /dev/null +++ b/meta-raspberrypi/docs/extra-build-config.md @@ -0,0 +1,254 @@ +# Optional build configuration + +There are a set of ways in which a user can influence different paramenters of +the build. We list here the ones that are closely related to this BSP or +specific to it. For the rest please check: +<http://www.yoctoproject.org/docs/latest/ref-manual/ref-manual.html> + +## Compressed deployed files + +1. Overwrite IMAGE_FSTYPES in local.conf + * `IMAGE_FSTYPES = "tar.bz2 ext3.xz"` + +2. Overwrite SDIMG_ROOTFS_TYPE in local.conf + * `SDIMG_ROOTFS_TYPE = "ext3.xz"` + +3. Overwrite SDIMG_COMPRESSION in local.conf + * `SDIMG_COMPRESSION = "xz"` + +Accommodate the values above to your own needs (ex: ext3 / ext4). + +## GPU memory + +* `GPU_MEM`: GPU memory in megabyte. Sets the memory split between the ARM and + GPU. ARM gets the remaining memory. Min 16. Default 64. + +* `GPU_MEM_256`: GPU memory in megabyte for the 256MB Raspberry Pi. Ignored by + the 512MB RP. Overrides gpu_mem. Max 192. Default not set. + +* `GPU_MEM_512`: GPU memory in megabyte for the 512MB Raspberry Pi. Ignored by + the 256MB RP. Overrides gpu_mem. Max 448. Default not set. + +* `GPU_MEM_1024`: GPU memory in megabyte for the 1024MB Raspberry Pi. Ignored by + the 256MB/512MB RP. Overrides gpu_mem. Max 944. Default not set. + +See: <https://www.raspberrypi.org/documentation/configuration/config-txt/memory.md> + +## Add purchased license codecs + +To add you own licenses use variables `KEY_DECODE_MPG2` and `KEY_DECODE_WVC1` in +local.conf. Example: + + KEY_DECODE_MPG2 = "12345678" + KEY_DECODE_WVC1 = "12345678" + +You can supply more licenses separated by comma. Example: + + KEY_DECODE_WVC1 = "0x12345678,0xabcdabcd,0x87654321" + +See: <https://www.raspberrypi.org/documentation/configuration/config-txt/codeclicence.md> + +## Disable overscan + +By default the GPU adds a black border around the video output to compensate for +TVs which cut off part of the image. To disable this set this variable in +local.conf: + + DISABLE_OVERSCAN = "1" + +## Disable splash screen + +By default a rainbow splash screen is shown after the GPU firmware is loaded. +To disable this set this variable in local.conf: + + DISABLE_SPLASH = "1" + +## Boot delay + +The Raspberry Pi waits a number of seconds after loading the GPU firmware and +before loading the kernel. By default it is one second. This is useful if your +SD card needs a while to get ready before Linux is able to boot from it. +To remove (or adjust) this delay set these variables in local.conf: + + BOOT_DELAY = "0" + BOOT_DELAY_MS = "0" + +## Set overclocking options + +The Raspberry Pi can be overclocked. As of now overclocking up to the "Turbo +Mode" is officially supported by the raspbery and does not void warranty. Check +the config.txt for a detailed description of options and modes. The following +variables are supported in local.conf: `ARM_FREQ`, `GPU_FREQ`, `CORE_FREQ`, +`SDRAM_FREQ` and `OVER_VOLTAGE`. + +Example official settings for Turbo Mode in Raspberry Pi 2: + + ARM_FREQ = "1000" + CORE_FREQ = "500" + SDRAM_FREQ = "500" + OVER_VOLTAGE = "6" + +See: <https://www.raspberrypi.org/documentation/configuration/config-txt/overclocking.md> + +## HDMI and composite video options + +The Raspberry Pi can output video over HDMI or SDTV composite (the RCA connector). +By default the video mode for these is autodetected on boot: the HDMI mode is +selected according to the connected monitor's EDID information and the composite +mode is defaulted to NTSC using a 4:3 aspect ratio. Check the config.txt for a +detailed description of options and modes. The following variables are supported in +local.conf: `HDMI_FORCE_HOTPLUG`, `HDMI_DRIVE`, `HDMI_GROUP`, `HDMI_MODE`, +`CONFIG_HDMI_BOOST`, `SDTV_MODE`, `SDTV_ASPECT` and `DISPLAY_ROTATE`. + +Example to force HDMI output to 720p in CEA mode: + + HDMI_GROUP = "1" + HDMI_MODE = "4" + +See: <https://www.raspberrypi.org/documentation/configuration/config-txt/video.md> + +## Video camera support with V4L2 drivers + +Set this variable to enable support for the video camera (Linux 3.12.4+ +required): + + VIDEO_CAMERA = "1" + +## Enable offline compositing support + +Set this variable to enable support for dispmanx offline compositing: + + DISPMANX_OFFLINE = "1" + +This will enable the firmware to fall back to off-line compositing of Dispmanx +elements. Normally the compositing is done on-line, during scanout, but cannot +handle too many elements. With off-line enabled, an off-screen buffer is +allocated for compositing. When scene complexity (number and sizes +of elements) is high, compositing will happen off-line into the buffer. + +Heavily recommended for Wayland/Weston. + +See: <http://wayland.freedesktop.org/raspberrypi.html> + +## Enable kgdb over console support + +To add the kdbg over console (kgdboc) parameter to the kernel command line, set +this variable in local.conf: + + ENABLE_KGDB = "1" + +## Disable rpi boot logo + +To disable rpi boot logo, set this variable in local.conf: + + DISABLE_RPI_BOOT_LOGO = "1" + +## Boot to U-Boot + +To have u-boot load kernel image, set in your local.conf: + + RPI_USE_U_BOOT = "1" + +This will select the appropriate image format for use with u-boot automatically. +For further customisation the KERNEL_IMAGETYPE and KERNEL_BOOTCMD variables can +be overridden to select the exact kernel image type (eg. zImage) and u-boot +command (eg. bootz) to be used. + +## Image with Initramfs + +To build an initramfs image: + +* Set this 3 kernel variables (in linux-raspberrypi.inc for example) + - kernel_configure_variable BLK_DEV_INITRD y + - kernel_configure_variable INITRAMFS_SOURCE "" + - kernel_configure_variable RD_GZIP y + +* Set the yocto variables (in linux-raspberrypi.inc for example) + - `INITRAMFS_IMAGE = "<a name for your initramfs image>"` + - `INITRAMFS_IMAGE_BUNDLE = "1"` + +* Set the meta-rasberrypi variable (in raspberrypi.conf for example) + - `KERNEL_INITRAMFS = "-initramfs"` + +## Enable SPI bus + +When using device tree kernels, set this variable to enable the SPI bus: + + ENABLE_SPI_BUS = "1" + +## Enable I2C + +When using device tree kernels, set this variable to enable I2C: + + ENABLE_I2C = "1" + +## Enable PiTFT support + +Basic support for using PiTFT screens can be enabled by adding below in +local.conf: + +* `MACHINE_FEATURES += "pitft"` + - This will enable SPI bus and i2c device-trees, it will also setup + framebuffer for console and x server on PiTFT. + +NOTE: To get this working the overlay for the PiTFT model must be build, added +and specified as well (dtoverlay=<driver> in config.txt). + +Below is a list of currently supported PiTFT models in meta-raspberrypi, the +modelname should be added as a MACHINE_FEATURES in local.conf like below: + + MACHINE_FEATURES += "pitft <modelname>" + +List of currently supported models: +* pitft22 +* pitft28r +* pitft35r + +## Misc. display + +If you would like to use the Waveshare "C" 1024×600, 7 inch Capacitive Touch +Screen LCD, HDMI interface (<http://www.waveshare.com/7inch-HDMI-LCD-C.htm>) Rev +2.1, please set the following in your local.conf: + + WAVESHARE_1024X600_C_2_1 = "1" + +## Enable UART + +RaspberryPi 0, 1, 2 and CM will have UART console enabled by default. + +RaspberryPi 0 WiFi and 3 does not have the UART enabled by default because this +needs a fixed core frequency and enable_uart wil set it to the minimum. Certain +operations - 60fps h264 decode, high quality deinterlace - which aren't +performed on the ARM may be affected, and we wouldn't want to do that to users +who don't want to use the serial port. Users who want serial console support on +RaspberryPi3 will have to explicitly set in local.conf: + + ENABLE_UART = "1" + +Ref.: +* <https://github.com/raspberrypi/firmware/issues/553> +* <https://github.com/RPi-Distro/repo/issues/22> + +## Enable USB Peripheral (Gadget) support + +The standard USB driver only supports host mode operations. Users who +want to use gadget modules like g_ether should set the following in +local.conf: + + ENABLE_DWC2_PERIPHERAL = "1" + +## Manual additions to config.txt + +The `RPI_EXTRA_CONFIG` variable can be used to manually add additional lines to +the `config.txt` file if there is not a specific option above for the +configuration you need. To add multiple lines you must include `\n` separators. +If double-quotes are needed in the lines you are adding you can use single +quotes around the whole string. + +For example, to add a comment containing a double-quote and a configuration +option: + + RPI_EXTRA_CONFIG = ' \n \ + # Raspberry Pi 7\" display/touch screen \n \ + lcd_rotate=2 \n \ + ' |