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diff --git a/import-layers/meta-raspberrypi/docs/extra-build-config.md b/import-layers/meta-raspberrypi/docs/extra-build-config.md new file mode 100644 index 0000000000..365c490688 --- /dev/null +++ b/import-layers/meta-raspberrypi/docs/extra-build-config.md @@ -0,0 +1,180 @@ +# 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. + +## 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" + + +## 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" + +## 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. Example turbo +mode: + + ARM_FREQ = "1000" + CORE_FREQ = "500" + SDRAM_FREQ = "500" + OVER_VOLTAGE = "6" + +## 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" + +## Boot to U-Boot + +To have u-boot load kernel image, set in your local.conf: + + KERNEL_IMAGETYPE = "uImage" + +This will make kernel.img be u-boot image which will load uImage. By default, +kernel.img is the actual kernel image (ex. Image). + +## 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 explicitely set in local.conf: + + ENABLE_UART = "1" + +Ref.: +* <https://github.com/raspberrypi/firmware/issues/553> +* <https://github.com/RPi-Distro/repo/issues/22> |