目录 1 创建 i.MX8QXP Linux 5.4.24 板级开发包编译环境 ..... 3 1.1 下载板级开发包 ....................................................... 3 1.2 创建yocto编译环境: ................................................. 4 1.3 独立编译 ................................................................. 9 2 Device Tree .............................................................. 16 2.1 恩智浦的device Tree结构 ..................................... 16 2.2 device Tree的由来(no updates) ............................ 19 2.3 device Tree的基础与语法(no updates) ................. 22 2.4 device Tree的代码分析(no updates) ..................... 44 3 恩智浦i.MX8XBSP 包文件目录结构 .......................... 77 4 恩智浦i.MX8XBSP的编译(no updates) ..................... 79 4.1 需要编译哪些文件 ................................................. 79 4.2 如何编译这些文件 ................................................. 80 4.3 如何链接为目标文件及链接顺序 ............................ 81 4.4 kernel Kconfig ....................................................... 83 5 恩智浦BSP的内核初始化过程(no updates) .............. 83 5.1 初始化的汇编代码 ................................................. 85 5.2 初始化的C代码 ...................................................... 89 5.3 init_machine........................................................ 102 6 恩智浦BSP的内核定制 ........................................... 105 6.1 DDR修改 ............................................................. 106 6.2 IO管脚配置与Pinctrl驱动 ..................................... 107 6.3 新板bringup......................................................... 123 6.4 更改调试串口 ...................................................... 132 6.5 uSDHC设备定制(eMMC flash,SDcard, SDIOcard)137 6.6 LVDS LCD 驱动定制 ........................................... 147 6.7 LVDS LDB SerDas驱动支持 ............................... 150 6.8 MiPi DSI SerDas驱动支持 .................................. 156 6.9 V4L2框架汽车级高清摄像头/桥驱动：数字/模拟 . 160 6.10 GPIO_Key 驱动定制 .......................................... 177 6.11 GPIO_LED 驱动定制 ......................................... 181 6.12 Fuse nvram驱动 .................................................. 184 6.13 SPI与SPI Slave驱动 ........................................... 185 6.14 USB 3.0 TypeC 改成 USB 3.0 TypeA(未验证) .... 193 6.15 汽车级以太网驱动定制 ........................................ 193 6.16 i.MX8DX MEK支持 .............................................. 212 6.17 i.MX8DXP MEK支持 ........................................... 212 6.18 NAND Flash支持与烧录 ...................................... 213

i.MX8X 板级开发包镜像结构 ...................................... 3 2 创建 i.MX8QXP Linux 5.4.24 板级开发包编译环境 ..... 3 2.1 下载板级开发包 ....................................................... 3 2.2 创建yocto编译环境: ................................................. 5 2.3 独立编译 ............................................................... 10 3 i.MX8X SC firmware ................................................. 16 3.1 SC firmware 目录结构 ........................................... 16 3.2 SC firmware 启动流程 ........................................... 18 3.3 SC firmware定制 ................................................... 18 4 i.MX8X ATF .............................................................. 30 5 FSL Uboot 定制 ........................................................ 32 5.1 FDT支持 ............................................................... 33 5.2 DM(driver model)支持 ........................................... 38 5.3 Uboot目录 结构 ..................................................... 52 5.4 Uboot编译 ............................................................. 54 5.5 Uboot初始化流程 .................................................. 55 5.6 uboot 定制 ............................................................ 66 5.7 uboot debug信息 ................................................... 82

Environment:   VMware player 15 + ubuntu 18.04 LTS Reference document: i.MX_Yocto_Project_User's_Guide.pdf 1. Software packages for the compilation # sudo apt-get install flex bison gperf build-essential zlib1g-dev # sudo apt-get install lib32ncurses5-dev x11proto-core-dev # sudo apt-get install libx11-dev lib32z1-dev libgl1-mesa-dev # sudo apt-get install tofrodos python-markdown libxml2-utils xsltproc # sudo apt-get install uuid-dev:i386 liblzo2-dev:i386 gcc-multilib g++-multilib # sudo apt-get install subversion openssh-server openssh-client uuid uuid-dev zlib1g-dev # sudo apt-get install liblz-dev lzop liblzo2-2 liblzo2-dev git-core curl # sudo apt-get install python3 python3-pip python3-pexpect python3-git python3-jinja2 pylint3 # sudo apt-get install u-boot-tools mtd-utils android-tools-fsutils # sudo apt-get install openjdk-8-jdk device-tree-compiler aptitude # sudo apt-get install libcurl4-openssl-dev nss-updatedb # sudo apt-get install chrpath texinfo gawk cpio diffstat # sudo apt-get install libncursesw5-dev libssl-dev libegl1-mesa # sudo apt-get install net-tools python libsdl1.2-dev xterm socat # sudo apt-get install icedtea-netx-common icedtea-netx 2. downloading yocto bsp (L5.4.24_2.1.0) # rm -rf ~/bin # mkdir ~/bin # curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo # chmod a+x ~/bin/repo # export PATH=~/bin:$PATH   # mkdir imx-yocto-bsp-5.4.24-2.1.0 # cd imx-yocto-bsp-5.4.24-2.1.0 # repo init -u https://source.codeaurora.org/external/imx/imx-manifest -b imx-linux-zeus -m imx-5.4.24-2.1.0.xml # cd .repo/manifests # gedit imx-5.4.24-2.1.0.xml          Modify git to https like below:   <remote fetch="https://git.yoctoproject.org/git" name="yocto"/>   <remote fetch="https://github.com/Freescale" name="community"/>   <remote fetch="https://github.com/openembedded" name="oe"/>   <remote fetch="https://github.com/OSSystems" name="OSSystems"/>   <remote fetch="https://github.com/meta-qt5"  name="QT5"/>   <remote fetch="https://github.com/TimesysGit"  name="Timesys"/>   <remote fetch="https://github.com/meta-rust"  name="rust"/>   <remote fetch="https://git.openembedded.org"  name="python2"/>   <remote fetch="https://source.codeaurora.org/external/imx" name="CAF"/> Save it and exit. # cd ~/ imx-yocto-bsp-5.4.24-2.1.0 # repo sync          Begin to compile i.MX8MQ BSP: # DISTRO=fsl-imx-wayland MACHINE=imx8mqevk source imx-setup-release.sh -b build-wayland          If users want to use chromium, do it like below, otherwise omit the step.        Add CORE_IMAGE_EXTRA_INSTALL += "chromium-ozone-wayland" to local.conf        And use 8 thread to compile BSP # gedit ./conf/local.conf …… BB_NUMBER_THREADS =”4” PARALLEL_MAKE =”-j 4” CORE_IMAGE_EXTRA_INSTALL += "chromium-ozone-wayland" ……          Save it and exit. [comment]          If your ubuntu has 8GB DDR, BB_NUMBER_THREADS can be set to “2”, PARALLEL_MAKE can be set to “-j 2”. # bitbake chromium-ozone-wayland -c fetch # bitbake imx-image-full Use ulimit -n 4096 to solve the issue. Then continue. # bitbake imx-image-full chromium compilation error:          Compile chromium-ozone-wayland separately. # bitbake chromium-ozone-wayland -c cleansstate # bitbake chromium-ozone-wayland -c compile          Use the command to solve the problem. # gedit ../sources/meta-imx/meta-sdk/dynamic-layers/browser-layer/recipes-browser/chromium/chromium-ozone-wayland_%.bbappend DEPENDS += "\         libxkbcommon \         virtual/egl \         wayland \         wayland-native \          mesa         \ "          Add mesa to DEPENDS          Save and exit.          Continue to compile it. # bitbake chromium-ozone-wayland -c compile          done, continue to compile full image   # bitbake imx-image-full Attachment is document in pdf format, which should be clear. NXP TIC team Weidong Sun 08/21/2020

Some customer need to know how to add support RS485 mode half duplex? Here give some recommends. About i.MX6 UART to RS485 applications 1. Using RS485 mode of UART directly. On hardware, you should use UART_CTS_B to control RX & TX. On software, The link for you reference: Does UART in RS485 mode support only 9 Bit mode for i.MX6 ?  2. Sensing IO direction Automatically via hardware, don't need to tune software. For i.MX8QXP As the linux BSP for i.MX8QXP do not support RS 485 mode, so for the RS 485 using you can use the Sensing IO direction Automatically via hardware, don't need to tune software. As the above i.MX6 design.

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