Raspberry pi 4b using Yocto
===

這一篇主要紀錄[Open Source Camera Project](https://hackmd.io/hUajGa4ORECGzliqR-K4ow)建置系統的步驟。

因為會用到攝影機，無線網路等功能，所以將一些必要套件也一起編譯進去

會用到的套件清單:
- meta-raspberrypi
- meta-openembedded
- meta-qt5
- meta-python2
- meta-browser
- meta-clang

範例有啟用Serial，所以不用透過螢幕也可以操作Raspberry pi。
:::info
登入=>
帳號: root
密碼: root
:::

---

1. 下載yocto:

git clone git://git.yoctoproject.org/poky
cd poky

2. 下載必須套件:

git clone git://git.yoctoproject.org/meta-raspberrypi
cd meta-raspberrypi
git checkout fb253346c2fe85f8fdd49e5a66dff04d8f2bd53e

git clone https://github.com/openembedded/meta-openembedded

git clone https://github.com/meta-qt5/meta-qt5

git clone https://github.com/OSSystems/meta-browser

git clone git://github.com/kraj/meta-clang

git clone git://git.openembedded.org/meta-python2

3. 新增專案:

source oe-init-build-env rpi-build

:::info
source oe-init-build-env <自己取專案名稱>
:::

4. 設定配方:

vim conf/bblayers.conf

將裡面改成:

# POKY_BBLAYERS_CONF_VERSION is increased each time build/conf/bblayers.conf
# changes incompatibly
POKY_BBLAYERS_CONF_VERSION = "2"

BBPATH = "${TOPDIR}"
BBFILES ?= ""

BBLAYERS ?= " \
  PATH/poky/meta \
  PATH/poky/meta-poky \
  PATH/poky/meta-yocto-bsp \
  PATH/poky/meta-raspberrypi \
  PATH/poky/meta-openembedded/meta-oe \
  PATH/poky/meta-openembedded/meta-multimedia \
  PATH/poky/meta-openembedded/meta-networking \
  PATH/poky/meta-openembedded/meta-python \
  PATH/poky/meta-qt5 \
  PATH//poky/meta-python2 \
  PATH//poky/meta-browser/meta-chromium \
  PATH//poky/meta-clang \
  "

:::info
PATH改為自己的實際路徑
:::

5. 設定環境變數:

vim conf/local.conf

新增:

MACHINE ??= "raspberrypi4"
KERNEL_IMAGETYPE = "Image"
ENABLE_UART = "1"
RASPBERRYPI_HD_CAMERA = "1"
VIDEO_CAMERA = "1"
PARALLEL_MAKE = "-j 4"
GPU_MEM_256="192"
DISABLE_OVERSCAN = "1"
DISABLE_SPLASH = "1"
DISABLE_RPI_BOOT_LOGO = "1"
MACHINE_FEATURES_append=" vc4graphics xf86-video-fbdev"
DISTRO_FEATURES_append = " opengl x11 fbdev"
MACHINE_FEATURES_remove=" wayland"
VC4GRAPHICS = "1"

:::info
fbdev針對HDMI和DSI螢幕
:::

加上註解:

#MACHINE ??= "qemux86-64"

解開註解:

DL_DIR ?= "${TOPDIR}/downloads"
SSTATE_DIR ?= "${TOPDIR}/sstate-cache"
TMPDIR = "${TOPDIR}/tmp"

PACKAGE_CLASSES ?= "package_rpm"
改成
PACKAGE_CLASSES ?= "package_ipk"

尾端新增:

IMAGE_ROOTFS_EXTRA_SPACE = "20971520"
IMAGE_INSTALL_append = " python3"
IMAGE_INSTALL_append  = " python3-pip"
IMAGE_INSTALL_append = " ntp"
IMAGE_INSTALL_append = " v4l-utils"
IMAGE_INSTALL_append = " opkg"
IMAGE_INSTALL_append = " opencv"
IMAGE_INSTALL_append = " userland"
IMAGE_INSTALL_append = " libgpiod"
IMAGE_INSTALL_append = " vim"
IMAGE_INSTALL_append = " rsync"
IMAGE_INSTALL_append = " tslib"
IMAGE_INSTALL_append = " openssh"
IMAGE_INSTALL_append = " python3-pyqt5"
IMAGE_INSTALL_append = " chromium-x11"

TOOLCHAIN_TARGET_TASK_append = " opencv"

INHERIT += "extrausers"
EXTRA_USERS_PARAMS = "usermod -P root root; "
LICENSE_FLAGS_WHITELIST="commercial"

:::info
IMAGE_INSTALL_append=" <套件>"
:::

:::info
INHERIT += "extrausers"
EXTRA_USERS_PARAMS = "usermod -P <登入帳號> <登入密碼>; "
:::

:::info
擴展rootfs到20GB
IMAGE_ROOTFS_EXTRA_SPACE = "20971520"
:::

6.相機patch:
[patch下載](https://drive.google.com/file/d/1e-CXmADIytuON-DWXSOUohHLmj_VLtaG/view?usp=sharing)

將patch丟到meta-raspberry資料夾底下，並應用。

git apply <PATH檔案>

7. 編譯:

bitbake core-image-x11

會看到:

Build Configuration:
BB_VERSION           = "1.51.0"
BUILD_SYS            = "x86_64-linux"
NATIVELSBSTRING      = "ubuntu-20.04"
TARGET_SYS           = "x86_64-poky-linux"
MACHINE              = "qemux86-64"
DISTRO               = "poky"
DISTRO_VERSION       = "3.3+snapshot-c553b55a48af077ce25480abcadac289c91051b5"
TUNE_FEATURES        = "m64 core2"
TARGET_FPU           = ""
meta                 
meta-poky            
meta-yocto-bsp       = "master:c553b55a48af077ce25480abcadac289c91051b5"

NOTE: Fetching uninative binary shim http://downloads.yoctoproject.org/releases/uninative/3.1/x86_64-nativesdk-libc.tar.xz;sha256sum=5d0611df544edff6428cef7d871257a91aa6ba1bd92f5365a2df8deb54b6b31e (will check PREMIRRORS first)
Initialising tasks:  44% |########################################################################                                                                                             | ETA:  0:00:00

8. 將編譯好的映像檔燒到SDCRD中開機:

sudo bmaptool copy tmp/deploy/images/raspberrypi4/core-image-x11-raspberrypi4.wic.bz2 <SDCORD所在位置>

9. 燒錄完成後，插上Raspberry pi開機，即可在console操作Raspberry pi

這裡透過screen操作console

sudo screen /dev/ttyUSB0 115200