This document describes the steps to create your own out-of-tree kernel module recipe for Yocto.

    Xenomai is real-time framework, which can run seamlessly side-by-side Linux as a co-kernel system, or natively over mainline Linux kernels (with or without PREEMPT-RT patch). The dual kernel nicknamed Cobalt, is a significant rework of the Xenomai 2.x system. Cobalt implements the RTDM specification for interfacing with real-time device drivers. The native linux version, an enhanced implementation of the experimental Xenomai/SOLO work, is called Mercury. In this environment, only a standalone implementation of the RTDM specification in a kernel module is required, for interfacing the RTDM-compliant device drivers with the native kernel. You can get more detailed information from Home · Wiki · xenomai / xenomai · GitLab       I have ported xenomai 3.1 to i.MX Yocto 4.19.35-1.1.0, and currently support ARM64 and test on i.MX8MQ EVK board. I did over night test( 5 real-time threads + GPU SDK test case) and stress test by tool stress-ng on i.MX8MQ EVK board. It looks lile pretty good. Current version (20200730) also support i.MX8MM EVK.     You need git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git, and git checkout xenomai-4.19.35-1.1.0-20200818 (which inlcudes all patches and bb file) and add the following variable in conf/local.conf before build xenomai by command bitbake xenomai.  XENOMAI_KERNEL_MODE = "cobalt"  PREFERRED_VERSION_linux-imx = "4.19-${XENOMAI_KERNEL_MODE}" IMAGE_INSTALL_append += " xenomai" or XENOMAI_KERNEL_MODE = "mercury" PREFERRED_VERSION_linux-imx = "4.19-${XENOMAI_KERNEL_MODE}" IMAGE_INSTALL_append += " xenomai" If XENOMAI_KERNEL_MODE = "cobalt", you can build dual kernel version. And If XENOMAI_KERNEL_MODE = "mercury", it is single kernel with PREEMPT-RT patch. The following is test result by the command (/usr/xenomai/demo/cyclictest -p 99 -t 5 -m -n -i 1000  -l 100000😞 //Over normal Linux kernel without GPU SDK test case T: 0 ( 4220) P:99 I:1000 C: 100000 Min: 7 Act: 10 Avg: 9 Max: 23 T: 1 ( 4221) P:99 I:1500 C: 66672 Min: 7 Act: 10 Avg: 10 Max: 20 T: 2 ( 4222) P:99 I:2000 C: 50001 Min: 7 Act: 12 Avg: 10 Max: 81 T: 3 ( 4223) P:99 I:2500 C: 39998 Min: 7 Act: 11 Avg: 10 Max: 29 T: 4 ( 4224) P:99 I:3000 C: 33330 Min: 7 Act: 13 Avg: 10 Max: 26 //Over normal Linux kernel with GPU SDK test case T: 0 ( 4177) P:99 I:1000 C: 100000 Min: 7 Act: 10 Avg: 11 Max: 51 T: 1 ( 4178) P:99 I:1500 C: 66673 Min: 7 Act: 12 Avg: 10 Max: 35 T: 2 ( 4179) P:99 I:2000 C: 50002 Min: 7 Act: 12 Avg: 11 Max: 38 T: 3 ( 4180) P:99 I:2500 C: 39999 Min: 7 Act: 12 Avg: 11 Max: 42 T: 4 ( 4181) P:99 I:3000 C: 33330 Min: 7 Act: 12 Avg: 11 Max: 36   //Cobalt with stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 512M --timeout 600s --metrics-brief T: 0 ( 4259) P:50 I:1000 C:3508590 Min:      0 Act:    0 Avg:    0 Max:      42 T: 1 ( 4260) P:50 I:1500 C:2338831 Min:      0 Act:    1 Avg:    0 Max:      36 T: 2 ( 4261) P:50 I:2000 C:1754123 Min:      0 Act:    1 Avg:    1 Max:      42 T: 3 ( 4262) P:50 I:2500 C:1403298 Min:      0 Act:    1 Avg:    1 Max:      45 T: 4 ( 4263) P:50 I:3000 C:1169415 Min:      0 Act:    1 Avg:    1 Max:      22   //Cobalt without GPU SDK test case T: 0 ( 4230) P:50 I:1000 C: 100000 Min: 0 Act: 0 Avg: 0 Max: 4 T: 1 ( 4231) P:50 I:1500 C:   66676 Min: 0 Act: 1 Avg: 0 Max: 4 T: 2 ( 4232) P:50 I:2000 C:   50007 Min: 0 Act: 1 Avg: 0 Max: 8 T: 3 ( 4233) P:50 I:2500 C:   40005 Min: 0 Act: 1 Avg: 0 Max: 3 T: 4 ( 4234) P:50 I:3000 C:   33338 Min: 0 Act: 1 Avg: 0 Max: 5 //Cobalt with GPU SDK test case T: 0 ( 4184) P:99 I:1000 C:37722968 Min: 0 Act: 1 Avg: 0 Max: 24 T: 1 ( 4185) P:99 I:1500 C:25148645 Min: 0 Act: 1 Avg: 0 Max: 33 T: 2 ( 4186) P:99 I:2000 C:18861483 Min: 0 Act: 1 Avg: 0 Max: 22 T: 3 ( 4187) P:99 I:2500 C:15089187 Min: 0 Act: 1 Avg: 0 Max: 23 T: 4 ( 4188) P:99 I:3000 C:12574322 Min: 0 Act: 1 Avg: 0 Max: 29 //Mercury without GPU SDK test case T: 0 ( 4287) P:99 I:1000 C:1000000 Min: 6 Act: 7 Avg: 7 Max: 20 T: 1 ( 4288) P:99 I:1500 C:  666667 Min: 6 Act: 9 Avg: 7 Max: 17 T: 2 ( 4289) P:99 I:2000 C:  499994 Min: 6 Act: 8 Avg: 7 Max: 24 T: 3 ( 4290) P:99 I:2500 C:  399991 Min: 6 Act: 9 Avg: 7 Max: 19 T: 4 ( 4291) P:99 I:3000 C:  333322 Min: 6 Act: 8 Avg: 7 Max: 21 //Mercury with GPU SDK test case T: 0 ( 4222) P:99 I:1000 C:1236790 Min: 6 Act: 7 Avg: 7 Max: 55 T: 1 ( 4223) P:99 I:1500 C:  824518 Min: 6 Act: 7 Avg: 7 Max: 44 T: 2 ( 4224) P:99 I:2000 C:  618382 Min: 6 Act: 8 Avg: 8 Max: 88 T: 3 ( 4225) P:99 I:2500 C:  494701 Min: 6 Act: 7 Avg: 8 Max: 49 T: 4 ( 4226) P:99 I:3000 C:  412247 Min: 6 Act: 7 Avg: 8 Max: 53 //////////////////////////////////////// Update for Yocto L5.4.47 2.2.0  /////////////////////////////////////////////////////////// New release for Yocto release L5.4.47 2.2.0 and it supports i.MX8M series (8MQ,8MM,8MN and 8MP). You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git,  and git checkout xenomai-5.4.47-2.2.0. You need to add the following variable in conf/local.conf before build xenomai by command bitbake imx-image-multimedia.  XENOMAI_KERNEL_MODE = "cobalt"  PREFERRED_VERSION_linux-imx = "5-${XENOMAI_KERNEL_MODE}" IMAGE_INSTALL_append += " xenomai" or XENOMAI_KERNEL_MODE = "mercury" PREFERRED_VERSION_linux-imx = "5-${XENOMAI_KERNEL_MODE}" IMAGE_INSTALL_append += " xenomai" //////////////////////////////////////// Update for Yocto L5.4.70 2.3.0  /////////////////////////////////////////////////////////// New release  for Yocto release L5.4.70 2.3.0 and it supports i.MX8M series (8MQ,8MM,8MN and 8MP) and i.MX8QM/QXP. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git and git checkout xenomai-5.4.70-2.3.0. Updating: 1, Support i.MX8QM and i.MX8QXP 2, Fix altency's the issue which uses legacy API to get time   //////////////////////////////////////// update for Yocto L5.4.70 2.3.2  /////////////////////////////////////////////////////////// New release for Yocto release L5.4.70 2.3.2. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git, and git checkout xenomai-5.4.70-2.3.2. Updating: 1, Enable Xenomai RTDM driver in Linux Kernel 2, Currently CAN, UART, GPIO,  SPI and Ethernet (in debug for RTNet)  are added in Xenomai. 3, Add KERNEL_DEVICETREE += " freescale/imx8mp-rt-evk.dtb " in sources/meta-imx/meta-bsp/conf/machine/imx8mpevk.conf to enable relative device in Xenomai domain, for example rt-imx8mp-flexcan.   //////////////////////////////////////// Update for Yocto L5.4.70 2.3.4  /////////////////////////////////////////////////////////// New release for Yocto release L5.4.70 2.3.4. You need to git clone  https://gitee.com/zxd2021-imx/xenomai-arm64.git and git checkout xenomai-5.4.70-2.3.4. Updating: 1, Enable RTNet FEC driver 2, Currently CAN, UART, GPIO,  SPI and Ethernet ( FEC Controller)  are added in Xenomai. 3, Add KERNEL_DEVICETREE += " freescale/imx8mp-rt-evk.dtb " in sources/meta-imx/meta-bsp/conf/machine/imx8mpevk.conf and KERNEL_DEVICETREE += " freescale/imx8mm-rt-ddr4-evk.dtb " in sources/meta-imx/meta-bsp/conf/machine/imx8mmddr4evk.conf to enable rt_fec device in Xenomai domain. Verifying the network connection by RTnet Ping Between i.MX8M Mini EVK and i.MX8M Plus EVK a, Setup test environment 1, Connect ENET1 of  i.MX8M Plus EVK (used as a master) and  ENET of i.MX8M Mini EVK (used as a slave) of  to a switch or hub 2, Modify /usr/xenomai/etc/rtnet.conf in i.MX8M Plus EVK board as the following: @@ -16,7 +16,7 @@ MODULE_EXT=".ko" # RT-NIC driver -RT_DRIVER="rt_eepro100" +RT_DRIVER="rt_fec" RT_DRIVER_OPTIONS="" # PCI addresses of RT-NICs to claim (format: 0000:00:00.0) @@ -30,8 +30,8 @@ REBIND_RT_NICS="" # The TDMA_CONFIG file overrides these parameters for masters and backup # masters. Leave blank if you do not use IP addresses or if this station is # intended to retrieve its IP from the master based on its MAC address. -IPADDR="10.0.0.1" -NETMASK="" +IPADDR="192.168.100.101" +NETMASK="255.255.255.0" # Start realtime loopback device ("yes" or "no") RT_LOOPBACK="yes" @@ -65,7 +65,7 @@ TDMA_MODE="master" # Master parameters # Simple setup: List of TDMA slaves -TDMA_SLAVES="10.0.0.2 10.0.0.3 10.0.0.4" +TDMA_SLAVES="192.168.100.102" # Simple setup: Cycle time in microsecond TDMA_CYCLE="5000" 3, Modify /usr/xenomai/etc/rtnet.conf in i.MX8M Mini EVK board as the following: @@ -16,7 +16,7 @@ MODULE_EXT=".ko" # RT-NIC driver -RT_DRIVER="rt_eepro100" +RT_DRIVER="rt_fec" RT_DRIVER_OPTIONS="" # PCI addresses of RT-NICs to claim (format: 0000:00:00.0) @@ -30,8 +30,8 @@ REBIND_RT_NICS="" # The TDMA_CONFIG file overrides these parameters for masters and backup # masters. Leave blank if you do not use IP addresses or if this station is # intended to retrieve its IP from the master based on its MAC address. -IPADDR="10.0.0.1" -NETMASK="" +IPADDR="192.168.100.102" +NETMASK="255.255.255.0" # Start realtime loopback device ("yes" or "no") RT_LOOPBACK="yes" @@ -59,13 +59,13 @@ STAGE_2_CMDS="" # TDMA mode of the station ("master" or "slave") # Start backup masters in slave mode, it will then be switched to master # mode automatically during startup. -TDMA_MODE="master" +TDMA_MODE="slave" # Master parameters # Simple setup: List of TDMA slaves -TDMA_SLAVES="10.0.0.2 10.0.0.3 10.0.0.4" +TDMA_SLAVES="192.168.100.102" # Simple setup: Cycle time in microsecond TDMA_CYCLE="5000" 4, rename imx8mm-rt-ddr4-evk.dtb to imx8mm-ddr4-evk.dtb in /run/media/mmcblk1p1,  rename imx8mp-rt-evk.dtb to imx8mp-evk.dtb in /run/media/mmcblk1p1, and reboot board. 5, Run the below command on i.MX8M Mini EVK board. cd /usr/xenomai/sbin/ ./rtnet start & 5, Run the below command on i.MX8M Plus EVK board. cd /usr/xenomai/sbin/ ./rtnet start & When you see the log (rt_fec_main 30be0000.ethernet (unnamed net_device) (uninitialized): Link is Up - 100Mbps/Full - flow control rx/tx) and you can run command "./rtroute" to check route table if the slave IP (192.168.100.102) is in route.. b, Verify the network connection using the command below: ./rtping -s 1024 192.168.100.102 //////////////////////////////////////// Update for Yocto L5.10.52 2.1.0  /////////////////////////////////////////////////////////// New release for Yocto release L5.10.52 2.1.0. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git and git checkout xenomai-5.10.52-2.1.0. Updating: 1, Upgrade Xenomai to v3.2 2, Enable Dovetail instead of ipipe. Copy xenomai-arm64 to <Yocto folder>/sources/meta-imx/meta-bsp/recipes-kernel, and add the following variable in conf/local.conf before build Image with xenomai enable by command bitbake imx-image-multimedia. XENOMAI_KERNEL_MODE = "cobalt" IMAGE_INSTALL_append += " xenomai" or XENOMAI_KERNEL_MODE = "mercury" IMAGE_INSTALL_append += " xenomai" Notice: If XENOMAI_KERNEL_MODE = "cobalt", you can build dual kernel version. And If XENOMAI_KERNEL_MODE = "mercury", it is single kernel with PREEMPT-RT patch.  Latency testing of Xenomai3.2+Dovetail with isolating CPU 2,3 ( Xenomai 3.2 on 8MM DDR4 EVK with GPU test case (GLES2/S08_EnvironmentMappingRefraction_Wayland) + iperf3 + 2 ping 65000 size + stress-ng --cpu 2 --io 2 --vm 1 --vm-bytes 256M --metrics-brief )😞 The following is test result by the command (/usr/xenomai/demo/cyclictest -a 2,3 -p 50 -t 5 -m -n -i 1000) root@imx8mmddr4evk:~# /usr/xenomai/demo/cyclictest -a 2,3 -p 50 -t 5 -m -n -i 1000 # /dev/cpu_dma_latency set to 0us policy: fifo: loadavg: 5.96 6.04 6.03 7/155 1349 T: 0 ( 615) P:50 I:1000 C:63448632 Min: 0 Act: 0 Avg: 0 Max: 55 T: 1 ( 616) P:50 I:1500 C:42299087 Min: 0 Act: 0 Avg: 1 Max: 43 T: 2 ( 617) P:50 I:2000 C:31724315 Min: 0 Act: 0 Avg: 1 Max: 51 T: 3 ( 618) P:50 I:2500 C:25379452 Min: 0 Act: 0 Avg: 1 Max: 53 T: 4 ( 619) P:50 I:3000 C:21149543 Min: 0 Act: 0 Avg: 1 Max: 47 //////////////////////////////////////// Update for Yocto L5.10.72 2.2.2  /////////////////////////////////////////////////////////// New release for Yocto release L5.10.72 2.2.2. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git and git checkout xenomai-5.10.72-2.2.2. Updating: 1, Upgrade Xenomai to v3.2.1 Copy xenomai-arm64 to <Yocto folder>/sources/meta-imx/meta-bsp/recipes-kernel, and add the following variable in conf/local.conf before build Image with xenomai enable by command bitbake imx-image-multimedia. XENOMAI_KERNEL_MODE = "cobalt" IMAGE_INSTALL_append += " xenomai" or XENOMAI_KERNEL_MODE = "mercury" IMAGE_INSTALL_append += " xenomai" //////////////////////////////////////// Update for Yocto L5.15.71 2.2.0  /////////////////////////////////////////////////////////// New release for Yocto release L5.15.71 2.2.0. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git and git checkout xenomai-5.15.71-2.2.0. Updating: 1, Upgrade Xenomai to v3.2.2 Copy xenomai-arm64 to <Yocto folder>/sources/meta-imx/meta-bsp/recipes-kernel, and add the following variable in conf/local.conf before build Image with xenomai enable by command bitbake imx-image-multimedia. XENOMAI_KERNEL_MODE = "cobalt" IMAGE_INSTALL:append += " xenomai" or XENOMAI_KERNEL_MODE = "mercury" IMAGE_INSTALL:append += " xenomai"   //////////////////////////////////////// Update for Yocto L6.1.55 2.2.0  /////////////////////////////////////////////////////////// New release for Yocto release L6.1.55 2.2.0. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm64.git recipes-rtlinux-xenomai -b Linux-6.1.x Updating: 1, Upgrade Xenomai to v3.2.4 and support i.MX93 2, Enable EVL (aka Xenomai 4) for i.MX93 and legacy i.MX(6/7D/8X/8M) Copy recipes-rtlinux-xenomai to <Yocto folder>/sources/meta-imx/meta-bsp/, and add the following variable in conf/local.conf before build Image with xenomai enable by command bitbake imx-image-multimedia. XENOMAI_KERNEL_MODE = "cobalt" IMAGE_INSTALL:append += " xenomai" or XENOMAI_KERNEL_MODE = "mercury" IMAGE_INSTALL:append += " xenomai" or XENOMAI_KERNEL_MODE = "evl" IMAGE_INSTALL:append += " libevl"  

Here we show how to bootstrap the Debian Linux distribution from a PC to the i.MX6 sabre sd platform. While bootstrapping Debian on any architecture "natively" is pretty straightforward, "cross-bootstrapping" requires some techniques that we will explain. This document assumes you are able to boot a Linux kernel on your platform already. See this post for details on how to do it. Also, this document assumes you are using a Debian PC for preparing your SD card. You will require the following packages to be installed: binfmt-support qemu-user-static debootstrap Note: all the commands found in the following steps need to be run as root. Formatting the SD card We need to format the SD card with two partitions; one small FAT partition to contain the Linux kernel and its dtb, and one large ext4 partition, which will contain the root filesystem with the Debian userspace. Also, we need to make sure we leave some space for u-boot starting from offset 1024B. Here is an example SD card layout:   +-----+------+--------+-----+---------------+-----------------   | MBR |  ... | u-boot | ... | FAT partition | Linux partition ...   +-----+------+--------+-----+---------------+-----------------   0     512    1024           1M              ~257M (offsets in bytes) Here is an example SD card layout, as displayed by fdisk:   Device    Boot      Start         End      Blocks   Id  System   /dev/sdc1            2048      526335      262144    c  W95 FAT32 (LBA)   /dev/sdc2          526336     8054783     3764224   83  Linux (units: 512B sectors) You can format and mount the Linux partition with:   # mkfs.ext4 /dev/<your-sd-card-second-partition>   # mount /dev/<your-sd-card-second-partition> /mnt Your SD card second partition is typically something in /dev/sd<X>2 or /dev/mmcblk<X>p2. Do not forget to install u-boot and a Linux kernel as explained in those posts. Bootstrapping Debian First stage The first stage of Debian bootstrapping is done with:   # debootstrap --foreign --arch=armhf testing /mnt This will retrieve the base Debian packages from the internet, and perform a first stage of installation:   I: Retrieving Release   I: Retrieving Release.gpg   I: Checking Release signature   I: Valid Release signature (key id A1BD8E9D78F7FE5C3E65D8AF8B48AD6246925553)   I: Validating Packages   I: Resolving dependencies of required packages...   I: Resolving dependencies of base packages...   I: Found additional required dependencies: insserv libbz2-1.0 libcap2 libdb5.1 libsemanage-common libsemanage1 libslang2 libustr-1.0-1   I: Found additional base dependencies: libee0 libept1.4.12 libestr0 libgcrypt11 libgnutls-openssl27 libgnutls26 libgpg-error0 libidn11 libjson-c2 liblognorm0 libmnl0 libnetfilter-acct1 libnfnetlink0 libp11-kit0 libsqlite3-0 libtasn1-3 libxapian22   I: Checking component main on http://ftp.us.debian.org/debian...   (...)   I: Extracting util-linux...   I: Extracting liblzma5...   I: Extracting zlib1g... At this point, the necessary tools for second stage of installation are under /mnt/debootstrap/. Second stage The second stage needs to run natively; on an arm platform, that is. But we can use the combination of two techniques to perform this stage on the PC anyway:   # cp /usr/bin/qemu-arm-static /mnt/usr/bin/   # chroot /mnt /debootstrap/debootstrap --second-stage Those commands copy an arm emulator on the target filesystem, and use the chroot command to execute the second stage of the installation into the SD card, on the PC, with transparent emulation:   I: Installing core packages...   I: Unpacking required packages...   I: Unpacking libacl1:armhf...   I: Unpacking libattr1:armhf...   I: Unpacking base-files...   (...)   I: Configuring tasksel...   I: Configuring tasksel-data...   I: Configuring libc-bin...   I: Base system installed successfully. You can now remove /mnt/usr/bin/qemu-arm-static, or keep it for later, subsequent chroot under emulation. Finetuning the root filesystem For development it is handy to remove the root password on the target by removing the '*' from /mnt/etc/shadow on the SD card:   root::15880:0:99999:7::: Also, we can add the following line in /mnt/etc/inittab to obtain a login prompt on the UART:   T0:23:respawn:/sbin/getty -L ttymxc0 115200 vt100 You can now unmount the filesystem with:   # umount /mnt Boot! Your SD card is ready for booting. Insert it in the SD card slot of your i.MX6 sabre sd platform, connect to the USB to UART port with a serial terminal set to 115200 baud, no parity, 8bit data and power up the platform. At the time of writing u-boot tells the kernel to boot from the wrong partition by default, so we need to interrupt by pressing enter at u-boot prompt for the first boot and setup u-boot environment to fix this:   U-Boot > setenv mmcroot /dev/mmcblk0p2 rootwait rw   U-Boot > saveenv   Saving Environment to MMC...   Writing to MMC(1)... done As this is saved in the SD card it need only to be done once at first boot. You can reboot your board or type boot; your Debian system should boot to a prompt:   (...)   [ ok ] Starting periodic command scheduler: cron.   [ ok ] Running local boot scripts (/etc/rc.local).   Debian GNU/Linux jessie/sid debian ttymxc0   debian login: From there you may login as root. It is recommended to setup the network connection and install an ssh server inside the target for further development. Enjoy! See also... With the amounts of memory we have today in the systems, it is even possible to boot Debian in a ramdisk. See this post about busybox for the ramdisk generation. Another way of generating a root filesystem is by building it with buildroot. See and this post for details.

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

INTRODUCTION REQUIREMENTS KERNEL DRIVER DEVICE NODE NFC LIBRARY TESTING NFC READER REFERENCES 1. INTRODUCTION This document is a step by step guide of the AN11697 PN7120 Linux Software Stack Integration Guidelines application note that can be downloaded from http://www.nxp.com/documents/application_note/AN11697.pdf . It explains how to add the PN7120 driver and NFC libraries to a Linux OS running in the i.MX6Q. 2. REQUIREMENTS The board used in this document is the Udoo Board thanks to the easy pin access. More information about this board can be found at Ultimate Single Board Mini PC for Android and Linux - UDOO A modified FSL L3.14.28 BSP. The modifications can be found in these 2 documents Basic Device Tree for the Udoo Board and  U-Boot Migration Example . If you have followed the previous documents, you already have a working yocto image and toolchain (meta-toolchain), if not you must follow this awesome training first Yocto Training - HOME . The OM5577/PN7120S demonstration kit. You can find more details of this board at http://www.nxp.com/documents/user_manual/UM10878.pdf 3. KERNEL DRIVER According to the AN11697.pdf we must follow the below steps: From the Linux source directory: $ cd drivers/misc $ git clone https://github.com/NXPNFCLinux/nxp-pn5xx.git Add the below line in the Makefile of the current directory obj-y += nxp-pn5xx/ Include the driver config in the drivers/misc/Kconfig file source "drivers/misc/nxp-pn5xx/Kconfig" Export the environment variables $ source source /opt/poky/1.7/environment-setup-cortexa9hf-vfp-neon-poky-linux-gnueabi $ export ARCH=arm $ export CROSS_COMPILE=$TARGET_PREFIX $ make imx_v7_defconfig Using menuconfig include the driver as module (<M>).  Compile the modules and install the .ko files into the target rootfs. $ make  modules You can send the .ko files with scp $ make  INSTALL_MOD_PATH=~/Desktop/modules modules_install $ cd ~/Desktop/modules $ sudo scp -r lib/modules/3.14.28+g91cf351/kernel root@<board_ip>:/lib/modules/3.14.28+g91cf351/ 4. DEVICE NODE The PN7120 interfaces with an MCU or MPU via I2C interface, therefore the device must be described into a i2c node. The signals used in the PN7120 are shown below: As you can see besides power, ground and I2C lines, an IRQ and Reset pins are needed. These pins must be configured as GPIO and one must generate an interrupt to the iMX6Q. The chosen connection is shown below: To achieve the above configuration, the device tree must be changed. The changes consist on adding a device node in the corresponding I2C bus, describing the PN7120. &i2c1 {         clock-frequency = <100000>;         pinctrl-names = "default";         pinctrl-0 = <&pinctrl_i2c1>;         status = "okay";         pn547: pn547@28 {                 compatible = "nxp,pn547";                 reg = <0x28>;                 clock-frequency = <400000>;                 interrupt-parent = <&gpio6>;                 interrupt-gpios = <&gpio6 2 0>;                 enable-gpios = <&gpio5 22 0>;         }; }; The pinctrl_i2c1 phandle contains the I2C pins configuration. Make sure that the PADs connected to the PN7120 are not used in other device node. &iomuxc {         imx6q-udoo {                       ...                 pinctrl_i2c1: i2c1grp {                         fsl,pins = <                         MX6QDL_PAD_GPIO_5__I2C3_SCL             0x4001b8b1                         MX6QDL_PAD_GPIO_6__I2C3_SDA             0x4001b8b1                         >;                 };         }; }; After this you can generate the dtb file and send it with scp make dtbs sudo scp arch/arm/boot/dts/imx6q-udoo.dtb root@<board_ip>:/run/media/mmcblk0p1/imx6q-udoo.dtb NOTE: Attached you can find the complete dts and dtsi files used in this document. 5. NFC LIBRARY     To work with the PN7120 in Linux the libnfc-nci stack is needed. You can find more details in http://www.nxp.com/documents/application_note/AN11697.pdf​ . This sections explains how to cross-compile the libray and install the required files in the target (The below steps must be performed in the host). Get the library $  git clone https://github.com/NXPNFCLinux/linux_libnfc-nci.git Generate the configuration script $ ./bootstrap Mount the target rootfs to /mnt in the host. $ sudo mount /dev/sdX2 /mnt Generate the Makefile $ ./configure --host=arm-none-linux --prefix=/opt/poky/1.7/sysroots/x86_64-pokysdk-linux/usr --sysconfdir=/mnt/etc Build and install the source code $ make $ make install After a succesful bulding the libraries and a application demo are built in .libs directory. Copy the libaries to /usr/lib directory of the target and nfcDemoApp to /usr/sbin $ cd linux_libnfc-nci/.libs $ sudo cp * /mnt/usr/lib/ 6. TESTING NFC READER     To test the application you have to follow the below steps on the target: Install the .ko file $ insmod /lib/modules/3.14.28+g91cf351/kernel/drivers/misc/nxp-pn5xx/pn5xx_i2c.ko Run the nfcDemoApp $  nfcDemoApp poll You should get a console output like the shown below when placing a NFC tag next to the NFC reader. 7. REFERENCES     Integrating NFC Controller library with KSDK http://www.nxp.com/documents/application_note/AN11697.pdf http://www.nxp.com/documents/user_manual/UM10878.pdf

The OpenSSL recipe halts saying it can't find find.pl . How to resolve this problem?   From the blog, linked below : create file find.pl in /etc/perl.   Missing find.pl compiling OE - Kemp's blog    "find.pl" content :   warn "Legacy library @{[(caller(0))[6]]} will be removed from the Perl core distribution in the next major release. Please install it from the CPAN distribution Perl4::CoreLibs. It is being used  at @{[(caller)[1]]}, line @{[(caller)[2]]}.\n";   # This library is deprecated and unmaintained. It is included for # compatibility with Perl 4 scripts which may use it, but it will be # removed in a future version of Perl. Please use the File::Find module # instead.   # Usage: #              require "find.pl"; # #              &find('/foo','/bar'); # #              sub wanted { ... } #                            where wanted does whatever you want. $dir contains the #                            current directory name, and $_ the current filename within #                            that directory. $name contains "$dir/$_". You are cd'ed #                            to $dir when the function is called. The function may #                            set $prune to prune the tree. # # For example, # # find / -name .nfs\* -mtime +7 -exec rm -f {} \; -o -fstype nfs -prune # # corresponds to this # #              sub wanted { #               /^\.nfs.*$/ && #               (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) && #               int(-M _) > 7 && #               unlink($_) #               || #               ($nlink || (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_))) && #               $dev < 0 && #               ($prune = 1); #              } # # Set the variable $dont_use_nlink if you're using AFS, since AFS cheats.   use File::Find ();   *name                            = *File::Find::name; *prune                            = *File::Find::prune; *dir                            = *File::Find::dir; *topdir                            = *File::Find::topdir; *topdev                            = *File::Find::topdev; *topino                            = *File::Find::topino; *topmode              = *File::Find::topmode; *topnlink              = *File::Find::topnlink;   sub find {   &File::Find::find(\&wanted, @_); }   1;

The Linux L4.9.11_1.0.0 RFP(GA) for i.MX6 release files are now available on www.nxp.com    Files available: # Name Description 1 L4.9.11_1.0.0-ga_images_MX6QPDLSOLOX.tar.gz i.MX 6QuadPlus, i.MX 6Quad, i.MX 6DualPlus, i.MX 6Dual, i.MX 6DualLite, i.MX 6Solo, i.MX 6Solox Linux Binary Demo Files 2 L4.9.11_1.0.0-ga_images_MX6SLEVK.tar.gz i.MX 6Sololite EVK Linux Binary Demo Files 3 L4.9.11_1.0.0-ga_images_MX6UL7D.tar.gz i.MX 6UltraLite EVK, 7Dual SABRESD, 6ULL EVK Linux Binary Demo Files 4 L4.9.11_1.0.0-ga_images_MX6SLLEVK.tar.gz i.MX 6SLL EVK Linux Binary Demo Files 5 L4.9.11_1.0.0-ga_images_MX7ULPEVK.tar.gz i.MX 7ULP EVK Linux Binary Demo Files  6 L4.9.11_1.0.0-ga_mfg-tools.tar.gz i.MX Manufacturing Toolkit for Linux L4.9.11_1.0.0 BSP 7 L4.9.11_1.0.0-ga_gpu-tools.tar.gz L4.9.11_1.0.0 i.MX VivanteVTK file 8 bcmdhd-1.141.100.6.tar.gz The Broadcom firmware package for i.MX Linux L4.9.11_1.0.0 BSP. 9 imx-aacpcodec-4.2.1.tar.gz Linux AAC Plus Codec for L4.9.11_1.0.0 10 fsl-yocto-L4.9.11_1.0.0.tar.gz L4.9.11_1.0.0 for Linux BSP Documentation. Includes Release Notes, User Guide.   Target boards: i.MX 6QuadPlus SABRE-SD Board and Platform i.MX 6QuadPlus SABRE-AI Board i.MX 6Quad SABRE-SD Board and Platform i.MX 6DualLite SABRE-SD Board i.MX 6Quad SABRE-AI Board i.MX 6DualLite SABRE-AI Board i.MX 6SoloLite EVK Board i.MX 6SoloX SABRE-SD Board i.MX 6SoloX SABRE-AI Board i.MX 7Dual SABRE-SD Board i.MX 6UltraLite EVK Board i.MX 6ULL EVK Board i.MX 6SLL EVK Board i.MX 7ULP EVK Board (Beta Quality)   What’s New/Features: Please consult the Release Notes.   Known issues For known issues and more details please consult the Release Notes.   More information on changes, see: README: https://source.codeaurora.org/external/imx/fsl-arm-yocto-bsp/tree/README?h=imx-morty ChangeLog: https://source.codeaurora.org/external/imx/fsl-arm-yocto-bsp/tree/ChangeLog?h=imx-morty

1.Test environment Board: i.MX8MPlus, RM67199 BSP: uboot 2022.04, linux-6.1.1-1.0.1 2.Modification of uboot  In uboot, you need comment the video_link_shut_down and dm_remove_devices_flags in announce_and_cleanup function. #if defined(CONFIG_VIDEO_LINK) //video_link_shut_down(); #endif board_quiesce_devices(); printf("\nStarting kernel ...%s\n\n", fake ? "(fake run for tracing)" : ""); /* * Call remove function of all devices with a removal flag set. * This may be useful for last-stage operations, like cancelling * of DMA operation or releasing device internal buffers. */ // #ifndef CONFIG_POWER_DOMAIN // dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL | DM_REMOVE_NON_VITAL); // /* Remove all active vital devices next */ // dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL); // #endif cleanup_before_linux(); }  After doing this, the uboot logo will not be cleaned before Linux PM framework. 3.Modification of Linux You need add  CONFIG_LOGO=n into defconfig file to disable kernel logo.  3.1 Disable the power down of mediamix and mipi-dphy in gpcv2.c Please add below code into the beginning of  imx_pgc_power_down function if ((strcmp(genpd->name, "mipi-phy1") == 0) || (strcmp(genpd->name, "mediamix") == 0)) { return 0; }  3.2 Only reset lcdif in the last call of drm framework Please modify imx_lcdifv3_runtime_resume function like this. The imx_lcdifv3_runtime_resume function will be called two times, thus the lcdif will be reset two times.We can let it only reset last time,which before the rootfs mount. bool rst = false; ////////////////////////////// static int imx_lcdifv3_runtime_resume(struct device *dev) { int ret = 0; struct lcdifv3_soc *lcdifv3 = dev_get_drvdata(dev); if (unlikely(!atomic_read(&lcdifv3->rpm_suspended))) { dev_warn(lcdifv3->dev, "Unbalanced %s!\n", __func__); return 0; } if (!atomic_dec_and_test(&lcdifv3->rpm_suspended)) return 0; /* set LCDIF QoS and cache */ if (of_device_is_compatible(dev->of_node, "fsl,imx93-lcdif")) regmap_write(lcdifv3->gpr, 0xc, 0x3712); request_bus_freq(BUS_FREQ_HIGH); ret = lcdifv3_enable_clocks(lcdifv3); if (ret) { release_bus_freq(BUS_FREQ_HIGH); return ret; } ////////////////////////////// if (rst) { /* clear sw_reset */ writel(CTRL_SW_RESET, lcdifv3->base + LCDIFV3_CTRL_CLR); rst = false; } rst = true; ////////////////////////////// /* enable plane FIFO panic */ lcdifv3_enable_plane_panic(lcdifv3); return ret; } 4.Conclusion The uboot logo will be cleaned at log "imx-drm 1.0.0 20120507 for display-subsystem on minor 1". The boot time of  systemd service on evk is very long. For weston.service, it needs 3 seconds. From log here we test, the pcie and ethernet probe after drm system also cost about 1 second. If you want to reduce the boot time of other modules, you can try to reduce the system service and disable pcie/ethernet drivers if you don't need them. [ 2.505616] [drm] Initialized imx-drm 1.0.0 20120507 for display-subsystem on minor 1 [ 2.620324] imx6q-pcie 33800000.pcie: iATU unroll: enabled [ 2.620335] imx6q-pcie 33800000.pcie: iATU regions: 4 ob, 4 ib, align 64K, limit 16G [ 2.720689] imx6q-pcie 33800000.pcie: PCIe Gen.1 x1 link up [ 2.820996] imx6q-pcie 33800000.pcie: PCIe Gen.2 x1 link up [ 2.821003] imx6q-pcie 33800000.pcie: Link up, Gen2 [ 2.821010] imx6q-pcie 33800000.pcie: PCIe Gen.2 x1 link up [ 2.821112] imx6q-pcie 33800000.pcie: PCI host bridge to bus 0000:00 [ 2.821119] pci_bus 0000:00: root bus resource [bus 00-ff] [ 2.821126] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] [ 2.821133] pci_bus 0000:00: root bus resource [mem 0x18000000-0x1fefffff] [ 2.821161] pci 0000:00:00.0: [16c3:abcd] type 01 class 0x060400 [ 2.821176] pci 0000:00:00.0: reg 0x10: [mem 0x00000000-0x000fffff] [ 2.821187] pci 0000:00:00.0: reg 0x38: [mem 0x00000000-0x0000ffff pref] [ 2.821232] pci 0000:00:00.0: supports D1 [ 2.821237] pci 0000:00:00.0: PME# supported from D0 D1 D3hot D3cold [ 2.824664] pci 0000:01:00.0: [1b4b:2b42] type 00 class 0x020000 [ 2.824725] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x000fffff 64bit pref] [ 2.824761] pci 0000:01:00.0: reg 0x18: [mem 0x00000000-0x000fffff 64bit pref] [ 2.825066] pci 0000:01:00.0: supports D1 D2 [ 2.825072] pci 0000:01:00.0: PME# supported from D0 D1 D3hot D3cold [ 2.835499] pci 0000:00:00.0: BAR 0: assigned [mem 0x18000000-0x180fffff] [ 2.835511] pci 0000:00:00.0: BAR 15: assigned [mem 0x18100000-0x182fffff pref] [ 2.835519] pci 0000:00:00.0: BAR 6: assigned [mem 0x18300000-0x1830ffff pref] [ 2.835530] pci 0000:01:00.0: BAR 0: assigned [mem 0x18100000-0x181fffff 64bit pref] [ 2.835561] pci 0000:01:00.0: BAR 2: assigned [mem 0x18200000-0x182fffff 64bit pref] [ 2.835590] pci 0000:00:00.0: PCI bridge to [bus 01-ff] [ 2.835598] pci 0000:00:00.0: bridge window [mem 0x18100000-0x182fffff pref] [ 2.835899] pcieport 0000:00:00.0: PME: Signaling with IRQ 218 [ 2.897767] Console: switching to colour frame buffer device 135x120 [ 3.098361] imx-drm display-subsystem: [drm] fb0: imx-drmdrmfb frame buffer device [ 3.111239] pps pps0: new PPS source ptp0 [ 3.316650] fec 30be0000.ethernet eth0: registered PHC device 0 [ 3.323645] imx-dwmac 30bf0000.ethernet: IRQ eth_lpi not found [ 3.329593] imx-dwmac 30bf0000.ethernet: force_sf_dma_mode is ignored if force_thresh_dma_mode is set. [ 3.340074] imx-dwmac 30bf0000.ethernet: User ID: 0x10, Synopsys ID: 0x51 [ 3.346883] imx-dwmac 30bf0000.ethernet: DWMAC4/5 [ 3.351684] imx-dwmac 30bf0000.ethernet: DMA HW capability register supported [ 3.358825] imx-dwmac 30bf0000.ethernet: RX Checksum Offload Engine supported [ 3.365966] imx-dwmac 30bf0000.ethernet: Wake-Up On Lan supported [ 3.372113] imx-dwmac 30bf0000.ethernet: Enable RX Mitigation via HW Watchdog Timer [ 3.379778] imx-dwmac 30bf0000.ethernet: Enabled L3L4 Flow TC (entries=8) [ 3.386573] imx-dwmac 30bf0000.ethernet: Enabled RFS Flow TC (entries=10) [ 3.393373] imx-dwmac 30bf0000.ethernet: Enabling HW TC (entries=256, max_off=256) [ 3.400950] imx-dwmac 30bf0000.ethernet: Using 34 bits DMA width [ 3.608045] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller [ 3.613580] xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 1 [ 3.621621] xhci-hcd xhci-hcd.1.auto: hcc params 0x0220fe6d hci version 0x110 quirks 0x0000002001010010 [ 3.631059] xhci-hcd xhci-hcd.1.auto: irq 226, io mem 0x38200000 [ 3.637197] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller [ 3.642698] xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 2 [ 3.650365] xhci-hcd xhci-hcd.1.auto: Host supports USB 3.0 SuperSpeed [ 3.657695] hub 1-0:1.0: USB hub found [ 3.661473] hub 1-0:1.0: 1 port detected [ 3.665669] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM. [ 3.674445] hub 2-0:1.0: USB hub found [ 3.678220] hub 2-0:1.0: 1 port detected [ 3.683428] imx-cpufreq-dt imx-cpufreq-dt: cpu speed grade 7 mkt segment 2 supported-hw 0x80 0x4 [ 3.693184] Hot alarm is canceled. GPU3D clock will return to 64/64 [ 3.702683] sdhci-esdhc-imx 30b50000.mmc: Got CD GPIO [ 3.703346] mxc-mipi-csi2-sam 32e40000.csi: supply mipi-phy not found, using dummy regulator [ 3.716645] : mipi_csis_imx8mp_phy_reset, No remote pad found! [ 3.722602] mxc-mipi-csi2-sam 32e40000.csi: lanes: 2, hs_settle: 13, clk_settle: 2, wclk: 1, freq: 500000000 [ 3.739353] mmc1: SDHCI controller on 30b50000.mmc [30b50000.mmc] using ADMA [ 3.752018] isi-m2m 32e00000.isi:m2m_device: Register m2m success for ISI.0 [ 3.759172] cfg80211: Loading compiled-in X.509 certificates for regulatory database [ 3.768303] cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7' [ 3.787598] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2 [ 3.795171] ALSA device list: [ 3.796227] platform regulatory.0: Falling back to sysfs fallback for: regulatory.db [ 3.799186] No soundcards found. [ 3.819630] EXT4-fs (mmcblk2p2): mounted filesystem with ordered data mode. Quota mode: none. [ 3.828212] VFS: Mounted root (ext4 filesystem) on device 179:2. [ 3.834944] devtmpfs: mounted

Hello, here Jorge. On this post I will explain how to configure, record and play audio using an i.MX 8MIC-RPI-MX8 Board. Requirements: I.MX 8M Mini EVK Linux Binary Demo Files - i.MX 8MMini EVK (L5.15.52_2.1.0) i.MX 8MIC-RPI-MX8 Board Serial console emulator (Tera Term, Putty, etc.) Headphones/speakers The 8MIC-RPI-MX8 accessory board is designed for voice enabled application prototyping and development on the i.MX 8M family. The board plugs directly into the 40-pin expansion connector on the i.MX 8M Mini and Nano EVK’s. Some features about this board are: 8 PDM Microphones 8 monochrome LEDs 4 multi-color LEDs 2 status LEDs 4 pushbuttons Microphone Mute Switch Microphone geometry switch Connecting the i.MX 8MIC-RPI-MX8 Board. The i.MX 8MIC-RPI-MX8 Board has a 40-pin expansion connector that you can plug it directly to the EVK board. Ensure that pin 1 of the 8MIC-RPI-MX8 is aligned with pin 1 on the EVK J1001 as is showed on the next figure:  Selecting the device tree on the board. Once the pre-compiled image is flashed on the board (Flashing Linux BSP using UUU) and you connected the 8MIC-RPI-MX8 it is necessary to select the correct device tree to handle 8MIC board. On U-boot check the available .dtb files on the BSP using the next command: u-boot=> fatls mmc 2:1 And you will get the corresponding list of .dbt files:  On this case we are working with an I.MX 8M Mini EVK and the corresponding .dtb file is: imx8mm-evk-8mic-revE.dtb To select it you need to set the environment variable and save it with: u-boot=> setenv fdtfile imx8mm-evk-8mic-revE.dtb u-boot=> saveenv Doble check it using: u-boot=> printenv fdtfile   Now it is time to boot Linux using the next command: u-boot=> boot Recording audio with the i.MX 8MIC-RPI-MX8 Board. The Advanced Linux Sound Architecture (ALSA) provides audio and MIDI functionality to the Linux operating system. ALSA has the following significant features: Efficient support for all types of audio interfaces, from consumer sound cards to professional multichannel audio interfaces. Fully modularized sound drivers. SMP and thread-safe design. User space library (alsa-lib) to simplify application programming and provide higher level functionality. Support for the older Open Sound System (OSS) API, providing binary compatibility for most OSS programs. Once we are on Linux, we can check our audio codecs detected on the board using: arecord -l   Now, to record audio we need to use the ALSA arecord command to start recording with IMX8 boards, there are different options that you can check on the next link. On this case we are going to use the next: arecord -D hw:imxaudiomicfil -c8 -f s16_le -r48000 -d10 sample.wav -D: selects the device. -c: selects the number of channels on the recording. -f: selects the format. -r: selects the sample rate. -d: determinate the duration recording time in seconds. sample.wav: Is the name of the resulting audio file. Running the last command, we started to record audio. It is time to make some noise and record it!   Playing audio from IMX8 boards. Now it is time to connect our headphones or speakers to the jack.   Also, as on arecord command you can check the devices where you can play audio from the board using the next command: aplay -l And you will get all the codecs to play audio:   To play our recordings we need to use the ALSA aplay command, it is important to select the correct audio codec to hear the audio from the jack on the board: aplay -Dplughw:3,0 sample.wav -D: selects the device. sample.wav: Is the name of audio file to play   Hope this will helpful for people who wants to record audio using PDM microphones and playing audio from IMX8 boards. Best regards.

meta-avs-demos Yocto layer meta-avs-demos is a Yocto meta layer (complementary to the NXP BSP release for i.MX) published on CodeAurora that includes the additional required packages to support  Amazon's Alexa Voice Services SDK (AVS_SDK) applications. The build procedure is the described on the README.md of the corresponding branch. We have 2 fuctional branches now: imx-alexa-sdk: Support for Morty based i.mx releases imx7d-pico-avs-sdk_4.1.15-1.0.0: legacy support for Jethro releases The master branch is only used to collect manifest files, that used with repo init/sync commands will fetch the whole environment for the 2 special supported boards: i.MX7D Pico Pi and i.MX8M EVK. However the meta-avs-demos can be used with any i.MX board either. Recipes to include Amazon's Alexa Voice Services in your applications. The meta-avs-demos provides the required recipes to build an i.MX image with the support for running Alexa SDK. The imx-alexa-sdk branch is based on Morty and kernel 4.9.X and it supports the next builds: i.MX7D Pico Pi i.MX8M EVK Generic i.MX board For the i.MX7D Pico Pi and i.MX8M EVK there is an extended support for additional (external) Sound Cards like: TechNexion VoiceHat: 2Mic Array board with DSPConcepts SW support Synaptics Card: 2 Mic with Sensory WakeWord support The Generic i.MX is for any other regular i.MX board supported on the official NXP BSP releases. Only the default soundcard (embedded) on the board is supported. Sensory wakeword is currently only enabled for those with ARMV7 architecture. To support any external board like the VoiceHat or Synaptics is up to the user to include the additional patches/changes required. Build Instructions Follow the corresponding README file to follow the steps to build an image with Alexa SDK support README-IMX7D-PICOPI.md README-IMX8M-EVK.md README-IMX-GENERIC.md

The purpose of the document is to help customer setup development  environment of android BSP, The document includes the following contents: 1.Setup environment for compiling android BSP source code 2. Setup tftp and NFS environment for android development 3. Common Steps of Porting android  to customized borad ( L3.0.35 kernel) Note: (1) ubuntu version is suitable for 12.04/14.04/15.04 (2) android BSP version is 4.2.2 / 4.3 / 4.4.2  If cusotmer is using android5.1.1 / android 6.0 or above, The way of porting kernel should be focused on adjusting device tree. (3)Each andoid BSP has its own MFG tools version. User should pay attention to this, don't use wrong version of MFG Tools. NXP TIC team Weidong Sun

This patch release is target for LPDDR2 ( dual channels in interleave mode ) support on i.MX6DL platform. Two patches are prepared to modify u-boot and kernel in order to have correct DRAM init sequence, 400MHz & 24MHz frequency switching and suspend/resume support. The patches are not fully verified. It is provided as reference for customer to enable their i.MX6DL board with LPDDR2. Customization and Testing is needed by customer. We need to remind some points here: MMDC_MDCFG3LP in 24MHz need to increase the margin ( 0x40222 -> 0x80555 ) in order to pass the OS frequency switch stress test. We are identifying the reason but this workaround is working fine and included to the patch. Code changes in kernel is prepared so that it is compatible to DDR3. In other words, the DDR type will be detected and a correct handling will be done for LPDDR2 and DDR3. In LPDDR2 system, we can't put SDQ pin into LPM during suspend. Otherwise, the system cannot resume. Dual channels in fix mapping mode is not recommended to use.

Q: How to program i.MX6 eFUSE? A: what about using the mfg tool? In the end only the supplies, USB OTG and the boot mode pins need to be connected. The customers Idea was to have all devices (i.MX6 eFUSE, Flash, PFUZE, etc) pre- programmed before mounting on the board. I presented the flows we support (MFG Tool, Platform SDK) for eFUSE programming last Friday when I was at the customer. KITPF0100SKTEVBE Product Summary Page MfgTools is the most convenient way to burn eFuse. Or the customer can burn the fuse on their jig/socket board by the u-boot: How to Fuse in U-Boot U-Boot contains a tool, imxotp, which is used for fusing. U-Boot > imxotp imxotp - One-Time Programable sub-system Usage: imxotp imxotp read <index> - read fuse at 'index' imxotp blow [--force] <index> <value> - blow fuse at 'index' with hex value 'value' Tips: 'addr' to 'index': convert 'index' from 'address' index = (addr - otp_base) / 0x10 eg, addr is 0x021bc410, otp_base is 0x021bc400, the index = 1 '--force' must be present in order to blow the fuse. Command will abort if '--force' is missing. index = (addr - otp_base) / 0x10, where the addr is the address of the fuse you want to operate, the otp_base is the base address of the fuse block. 'value' should correspond to fuse settings according to the fuse map and desired fuse configuration. ---------------------------------- FIrst of all thanks for your reply. However both flow assumes the i.MX6 is already soldered on the board. Please note the specific request was if it is possible (and we can support a programming house) to pre program the efuses BEFORE they are soldered on the PCB thus on a standard programmer. Take an FLASH programmer as an example.

By default Linux BSP will work with LVDS screen on i.MX 6SoloX SABRE board. To enable MCIMX28LCD on the board, following need to be modified in u-boot: setenv panel 'MCIMX28LCD' setenv fdt_file 'imx6sx-sdb-lcdif1.dtb' #add video=mxc_lcdif:SEIKO-WVGA,bpp=16 to kernel command line you’re using #For example, when booting from MMC it will be: #  setenv mmcargs 'setenv bootargs console=${console},${baudrate} root=${mmcroot} video=mxc_lcdif:SEIKO-WVGA,bpp=16' saveenv

Some customers often use LVDS LCD with low resolution on i.MX6 platform, such as 320x240, but by defualt , linux bsp doesn't support low frequency pixel clock for LVDS module input. Question:     When we port LVDS LCD with 320x240 resolution to android4.2.2, we found pixel clock is not correct, it always output 38.9MHz, it is no probem for big resolution , for example 1024x768, but the clock we need for 320x240 LCD is 6.4MHz.     According to the quesiton, Let us check IPU & LDB clock in i.MX6 datasheet at first : From above table, if ldb clock is from IPU, we will not get 6.4MHz pixel clock, so we will have to adjust its source clock: The following steps are procedure that ports LVDS LCD with 320x240 resolution to i.MX6Q. 1. Adding LVDS LCD timing structure to ldb.c static struct fb_videomode ldb_modedb[] = { {       "LDB-XGA", 60, 320, 240, 155914,       38, 20,       15, 4,       30, 3,       0,       FB_VMODE_NONINTERLACED,       FB_MODE_IS_DETAILED, }, {      "LDB-1080P60", 60, 1920, 1080, 7692,      100, 40,      30, 3,      10, 2,      0,      FB_VMODE_NONINTERLACED,      FB_MODE_IS_DETAILED,}, }; 2.Modifying clock source of ldb module Checking /arch/arm/mach-mx6/clock.c, we can find there are 3 ldb's clock source : &pll5_video_main_clk, &pll2_pfd_352M, &pll2_pfd_400M, static int _clk_ldb_di1_set_parent(struct clk *clk, struct clk *parent) {        u32 reg, mux;        int rev = mx6q_revision();        reg = __raw_readl(MXC_CCM_CS2CDR)               & ~MXC_CCM_CS2CDR_LDB_DI1_CLK_SEL_MASK;        mux = _get_mux6(parent, &pll5_video_main_clk,               &pll2_pfd_352M, &pll2_pfd_400M,               (rev == IMX_CHIP_REVISION_1_0) ?                &pll3_pfd_540M :       /* MX6Q TO1.0 */                &mmdc_ch1_axi_clk[0],     /* MX6Q TO1.1 and MX6DL */               &pll3_usb_otg_main_clk, NULL);        reg |= (mux << MXC_CCM_CS2CDR_LDB_DI1_CLK_SEL_OFFSET);        __raw_writel(reg, MXC_CCM_CS2CDR);        return 0; } By default, pll2_pfd_352M is configured as the clock source of ldb: clk_set_parent(&ldb_di0_clk, &pll2_pfd_352M);        clk_set_parent(&ldb_di1_clk, &pll2_pfd_352M); We should change the clock source to be pll5_video_main_clk clk_set_parent(&ldb_di0_clk, &pll5_video_main_clk,);        clk_set_parent(&ldb_di1_clk, &pll5_video_main_clk,); 3. Configuring initial clock in board-mx6q_sabresd.c static struct ipuv3_fb_platform_data sabresd_fb_data[] = {        { /*fb0*/        .disp_dev = "ldb",        .interface_pix_fmt = IPU_PIX_FMT_RGB666,        .mode_str = "LDB-XGA",        .default_bpp = 16,        .int_clk = false,        .late_init = false, } int_clk=false means LDB clock is from PLL2_PFD_352 or pll5_video_main_clk; int_clk=true mean LDB clock if from IPU. OK, after doing above steps, LVDS LCD with low resolution should normally work. Freescale TICS team Weidong.sun 2015-08-18

 This article uses i.MX Linux® User's Guide, Rev. L4.1.15_2.1.0-ga, 05/2017 as an example (it may be found as attachment), please refer to section 4.5.12 (How to build U-Boot and Kernel in standalone environment).   First, generate a development SDK, which includes the tools, toolchain, and small rootfs to compile against to put on the host machine.     • Generate an SDK from the Yocto Project build environment with the following command. To set up the Yocto Project build environment, follow the steps in the i.MX Yocto Project User's Guide (IMXLXYOCTOUG). In the following command, set <Target-Machine> to the machine you are building for.   <Target-Machine> may be one of the following :   • imx6qpsabreauto • imx6qpsabresd • imx6ulevk • imx6ull14x14evk • imx6ull9x9evk • imx6dlsabreauto • imx6dlsabresd • imx6qsabreauto • imx6qsabresd • imx6slevk • imx6sllevk • imx6solosabreauto • imx6solosabresd • imx6sxsabresd • imx6sxsabreauto • imx7dsabresd  The «populate_sdk» generates an script file that sets up environment without Yocto Project. This SDK should be updated for each release to pick up the latest headers, toolchain, and tools from the current release.   $ DISTRO=fsl-imx-fb MACHINE=<Target-Machine> source fsl-setup-release.sh -b build-fb   $ DISTRO=fsl-imx-fb MACHINE=<Target-Machine> bitbake core-image-minimal -c populate_sdk   or   $ bitbake meta-toolchain       • From the build directory, the bitbake was run in, copy the sh file in tmp/deploy/sdk to the host machine to build on and execute the script to install the SDK. The default location is in /opt but can be placed anywhere on the host machine.     Note. Each time you wish to use the SDK in a new shell session, you need to source the environment setup script e.g.    $ . /opt/fsl-imx-fb/4.1.15-2.0.0/environment-setup-cortexa9hf-neon-poky-linux-gnueabi   or    $ source /opt/fsl-imx-fb/4.1.15-2.0.0/environment-setup-cortexa9hf-neon-poky-linux-gnueabi   From  Yocto Project Mega-Manual  Note By default, this toolchain does not build static binaries. If you want to use the toolchain to build these types of libraries, you need to be sure your image has the appropriate static development libraries. Use the  IMAGE_INSTALL  variable inside your  local.conf  file to install the appropriate library packages. Following is an example using  glibc  static development libraries:      IMAGE_INSTALL_append = " glibc-staticdev"   On the host machine, these are the steps to build U-Boot and Kernel:  • On the host machine, set the environment with the following command before building.   $ export CROSS_COMPILE=/opt/fsl-imx-fb/4.1.15/environment-setup-cortexa9hf-vfp-neon-pokylinux-gnueabi   $ export ARCH=arm • To build U-Boot, find the configuration for the target boot. In the following example, i.MX 6ULL is the target.     Download source by cloning with   $ git clone http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git -b imx_v2016.03_4.1.15_2.0.0_ga   $ cd uboot-imx $ make clean $ make mx6ull_14x14_evk_defconfig $ make u-boot.imx   • To build the kernel, execute the following commands:   Download source by cloning with   $ git clone http://git.freescale.com/git/cgit.cgi/imx/linux-imx.git -b imx_4.1.15_2.0.0_ga   $ cd linux-imx $ make defconfig $ make   • To build an application (Hello World) as test.c:   $ source /opt/fsl-imx-fb/4.1.15-2.0.0/environment-setup-cortexa9hf-neon-poky-linux-gnueabi $ cd ~/test/ $ arm-poky-linux-gnueabi-gcc --sysroot=/opt/fsl-imx-fb/4.1.15-2.0.0/sysroots/cortexa9hf-neon-poky-linux-gnueabi -mfloat-abi=hard test.c To check if the the compiled code (a.out) is ARM executable   $ file ./a.out   ./a.out: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 2.6.32, BuildID[sha1]=0e5c22dcf021748ead2c0bd51a4553cb7d38f6f2, not stripped   Copy file a.out to target Linux filesystem and before run it check again :   root@imx6ul7d:/unit_tests/1# file a.out   a.out: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 2.6.32, BuildID[sha1]=0e5c22dcf021748ead2c0bd51a4553cb7d38f6f2, not stripped   To define what Linux libs are needed to run our application :   root@imx6ul7d:/unit_tests/1# ldd a.out     linux-vdso.so.1 (0x7ee93000)   libc.so.6 => /lib/libc.so.6 (0x76e64000)   /lib/ld-linux-armhf.so.3 (0x76f9d000)   If some libs are not located in the filesystem you can observe the following message :   -sh: root@imx6ul7d:/unit_tests/1#./a.out: No such file or directory   Finally - run a.out:   root@imx6ul7d:/unit_tests/1# ./a.out Hello World root@imx6ul7d:/unit_tests/1#

Using a RAW NAND is more difficult compared to eMMC, but for lower capacity it is still cheaper. Even with the ONFI (Open NAND Flash Interface) you can face initialization issue you can find by measure performance. I will take example of a non-well supported flash, I have installed on my evaluation board (SABRE AI). I wanted to do a simple performance test, to check roughly the MB/s I can expected with this NAND. One of a simplest test is to use the dd command: root@imx6qdlsolo:~# time dd if=/dev/mtd4 of=/dev/null 851968+0 records in 851968+0 records out 436207616 bytes (436 MB, 416 MiB) copied, 131.8884 s, 3.3 MB/s ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ As my RAW was supposed to work in EDO Mode 5, I could expect more than 20MB/s. To check what was wrong, read you kernel startup log: Booting Linux on physical CPU 0x0 Linux version 4.1.15-2.0.0+gb63f3f5 (bamboo@yb6) (gcc version 5.3.0 (GCC) ) #1 SMP PREEMPT Fri Sep 16 15:02:15 CDT 2016 CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c53c7d CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache Machine model: Freescale i.MX6 DualLite/Solo SABRE Automotive Board [...] Amd/Fujitsu Extended Query Table at 0x0040 Amd/Fujitsu Extended Query version 1.3. number of CFI chips: 1 nand: device found, Manufacturer ID: 0xc2, Chip ID: 0xdc nand: Macronix MX30LF4G18AC nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64 gpmi-nand 112000.gpmi-nand: mode:5 ,failed in set feature. Bad block table found at page 262080, version 0x01 Bad block table found at page 262016, version 0x01 nand_read_bbt: bad block at 0x00000a7e0000 nand_read_bbt: bad block at 0x00000dc80000 4 cmdlinepart partitions found on MTD device gpmi-nand Creating 4 MTD partitions on "gpmi-nand":‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ On line 13 you can read "mode:5, failed in set feature", meaning you are not in mode 5... so you have the "relaxed" timing you have at boot. After debuging your code (I have just remove the NAND back reading security check), you can redo the test: root@imx6qdlsolo:~# time dd if=/dev/mtd4 of=/dev/null 851968+0 records in 851968+0 records out 436207616 bytes (436 MB, 416 MiB) copied, 32.9721 s, 13.2 MB/s‍‍‍‍‍‍‍‍‍‍‍‍ So you multiplied the performances by 4! Anyway, you have a better tool to measure your NAND performance, it is mtd_speedtest, but you have to rebuild your kernel. In Yocto, reconfigure your kernel (on your PC of couse!): bitbake virtual/kernel -c menuconfig‍‍‍ Choose in the menu "Device Drivers" -> "Memory Technology Device (MTD) support" -> "MTD tests support", even it it not recommended! bitbake virtual/kernel -f -c compile bitbake virtual/kernel -f -c build bitbake virtual/kernel -f -c deploy‍‍‍‍‍‍‍‍‍ Then reflash you board (kernel + rootfs as tests are .ko files): Then you can do more accurate performance test: insmod /lib/modules/4.1.29-fslc+g59b38c3/kernel/drivers/mtd/tests/mtd_speedtest.ko dev=2 ================================================= mtd_speedtest: MTD device: 2 mtd_speedtest: MTD device size 16777216, eraseblock size 131072, page size 2048, count of eraseblocks 128, pages per eraseblock 64, OOB size 64 mtd_test: scanning for bad eraseblocks mtd_test: scanned 128 eraseblocks, 0 are bad mtd_speedtest: testing eraseblock write speed mtd_speedtest: eraseblock write speed is 4537 KiB/s mtd_speedtest: testing eraseblock read speed mtd_speedtest: eraseblock read speed is 16384 KiB/s mtd_speedtest: testing page write speed mtd_speedtest: page write speed is 4250 KiB/s mtd_speedtest: testing page read speed mtd_speedtest: page read speed is 15784 KiB/s mtd_speedtest: testing 2 page write speed mtd_speedtest: 2 page write speed is 4426 KiB/s mtd_speedtest: testing 2 page read speed mtd_speedtest: 2 page read speed is 16047 KiB/s mtd_speedtest: Testing erase speed mtd_speedtest: erase speed is 244537 KiB/s mtd_speedtest: Testing 2x multi-block erase speed mtd_speedtest: 2x multi-block erase speed is 252061 KiB/s mtd_speedtest: Testing 4x multi-block erase speed mtd_speedtest: 4x multi-block erase speed is 256000 KiB/s mtd_speedtest: Testing 8x multi-block erase speed mtd_speedtest: 8x multi-block erase speed is 260063 KiB/s mtd_speedtest: Testing 16x multi-block erase speed mtd_speedtest: 16x multi-block erase speed is 260063 KiB/s mtd_speedtest: Testing 32x multi-block erase speed mtd_speedtest: 32x multi-block erase speed is 256000 KiB/s mtd_speedtest: Testing 64x multi-block erase speed mtd_speedtest: 64x multi-block erase speed is 260063 KiB/s mtd_speedtest: finished =================================================‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ You can now achieve almost 16MB/s, better than the dd test. Of course you cannot achieve more than 20MB/s, but you are not that far, and the NAND driver need optimizations. To redo the test: rmmod /lib/modules/4.1.29-fslc+g59b38c3/kernel/drivers/mtd/tests/mtd_speedtest.ko insmod /lib/modules/4.1.29-fslc+g59b38c3/kernel/drivers/mtd/tests/mtd_speedtest.ko dev=2 To check your NAND is in EDO mode 5, you can check your clock tree: /unit_tests/dump-clocks.sh clock          parent   flags    en_cnt pre_cnt      rate [...] gpmi_bch_apb   ---      00000005   0       0       198000000 gpmi_bch       ---      00000005   0       0       198000000 gpmi_io        ---      00000005   0       0        99000000 gpmi_apb       ---      00000005   0       0       198000000‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ The IO are clocked now at 99MHz, thus you can read at 49.5MHz (20ns in EDO mode 5 definition).

When to improve kernel booting using hibernation [1], I found kernel initialized each component [2] took too much time. One solution is to remove unnecessary module to save time. Another approach is to delay those modules until user space up. Then it won’t lost some features just because hopes to gain benefit on booting speed. This is very useful since hibernation’s trigger point is at the late_initcall [3]. Kernel doesn't need do much module initialize since hibernate will restore those module status later. The detailed implementation is in the attached patch. [1]: hibernation is a technique to store system memory content to storage. Then the device can be shutdown and read the content back after power on. [2]: component means subsystem or driver. [3]: Consult kernel/power/hibernate.c, software_resume

INTRODUCTION REQUIREMENTS CREATE A NEW PROJECT GPU EXAMPLE GSTREAMER EXAMPLE 1. INTRODUCTION:      The below steps show how to create different application examples using Elipse IDE. 2. REQUIREMENTS:      A fully working image and meta-toolchain generated in Yocto . You can follow the  next training: Yocto Training - HOME      Install and configure the Yocto Eclipse Plug-in. For more details about this requirement please refer to Setting up the Eclipse IDE for Yocto Application Development         To demonstrate the steps, L3.14.28  BSP, fsl-image-qt5 image and i.MX6Q SABRE-SDP board were used. 3. CREATE A NEW PROJECT      Follow the section Creating a Hello World Project of this document Setting up the Eclipse IDE for Yocto Application Development 4. GPU EXAMPLE           For this project we use the source code found in the fsl-gpu-sdk that can be downloaded from:      https://www.freescale.com/webapp/Download?colCode=IMX6_GPU_SDK&location=null&Parent_nodeId=1337637154535695831062&Parent…      Follow section 3 and create a new project named gputest.      From the IMX6_GPU_SDK choose one of the examples of GLES2.0 folder. In this case the 01_SimpleTriangle is chosen.      Copy the .c and .h files to the src directory of the gputest project. The Project Explorer window should look like this:              Add the needed files and libraries to compile and link in the Makefile.am file found in the ´src´ folder. The Makefile.am file should have the below content:          bin_PROGRAMS = gputest          gputest_SOURCES = gputest.c fsl_egl.c fslutil.c          AM_CFLAGS = @gputest_CFLAGS@          AM_LDFLAGS = @gputest_LIBS@ -lstdc++ -lm -lGLESv2 -lEGL -lX11 -ldl          CLEANFILES = *~ ​    Add the PATH to CFLAGS where the compiler will look for the headers at Project->Properties->Autotools->configure:           In this project there is no need to add extra PATHs for the headers. Apply the changes by clicking on Reconfigure Project. Build the project To test the file you can send the executable to the board with:           $ scp gputest root@<board_ip>:/home/root      $./gputest      You should get the next output in the display: 5. GSTREAMER EXAMPLE      For this project we use the source code found at Basic tutorial 1: Hello world! - GStreamer SDK documentation - GStreamer SDK documentation    Follow section 3 and create a new project named Gstreamer.    Copy the code of the basic tutorial to your Gstreamer.c file.    Add the needed files and libraries to compile and link in the Makefile.am file found in the ´src´ folder. The Makefile.am file should have the below content:                           bin_PROGRAMS = Gstreamer      Gstreamer_SOURCES = Gstreamer.c      AM_CFLAGS = @Gstreamer_CFLAGS@      AM_LDFLAGS = @Gstreamer_LIBS@ -lstdc++  -lVDK -lm -lGLESv2 -lGAL -lEGL  -ldl -lgstreamer-0.10 -lgobject-2.0 -lgmodule-2.0 -lgthread-2.0 -lrt -lxml2 -lglib-2.0      CLEANFILES = *~         ​    Add the PATH to CFLAGS where the compiler will look for the headers at Project->Properties->Autotools->configure:           For this example the next lines are added             -I${Sysroot}/usr/include/gstreamer-1.0        -I${Sysroot}/usr/include/glib-2.0        -I${Sysroot}/usr/include/libxml2        -I${Sysroot}/usr/lib/glib-2.0/include      Apply the changes by clicking on Reconfigure Project. Build the project To test the file you can send the executable to the board with:           $ scp Gstreamer root@<board_ip>:/home/root To execute the application on the board:      $./Gstreamer The board should have internet access and the application should play the video found at http://docs.gstreamer.com/media/sintel_trailer-480p.webm

Overview As more and more communication required between online and offline, the QR code is widely used in the mobile payment, mobile small apps, industry things identification and etc. The i.MX6UL/ULL has the IP of CSI and PXP for camera connection and image CSC/FLIP/ROTATION acceleration. A LCDIF IP is supporting the display, but no 3D IP support. This means this low power and low end AP is very suitable for the industry HMI segment, which does not require a cool 3D graphic display, but a simple and straightforward GUI for interaction. QR code scanner is one of the use cases in the industry segment, which more and more customer are focusing on. The i.MX6UL CPU freq of i.MX6UL is about 500Mhz, and it does not have GPU IP, so a lightweight GUI and window system is required. Here we recommend the QT with wayland backend (without X11), which would make the window system small and faster than traditional X11 UI. Why chose QT is because of it has open source version, rich components, platform independent, good performance for embedded system and strong development staffs like QtCreator for creating application. How to enable the QT development environment, check this: Enable QT developement for i.MX6UL (v2)  Here I made a QR code scanner demo based on QT5.6 + QZXing (QR/Bar code scan engine) running on the i.MX6UL EVK board with a UVC camera (at least 640x480 resolution is required) and 480x272px LCD. Source code is open here (License Apache2.0): https://github.com/muddog/QRScanner  Implementation To do camera preview and capture, you must think on the gstreamer first, which is easy use and has the acceleration pads which implemented by NXP for i.MX6UL. Yes, it's very easy for you to enable the preview in console like: $ gst-launch-1.0 v4l2src device=/dev/video1 ! video/x-raw,format=YUY2,width=640,height=320 ! imxvideoconvert_pxp ! video/x-raw,format=RGB16 ! waylandsink It works under the i.MX6UL EVK, with PXP IP to do color space convert from YUY2 -> RGB16 acceleration, also the potential scaling of the image. The CPU loading of this is about 20-30%, but if you use the component of "videoconvert" to replace the "imxvideoconvert_pxp", we do CSC and scale by CPU, then the loading would increase to 50-60%. The "/dev/video1" is the device node for UVC camera, it may different in your environment. So our target is clear, create such pipeline (with PXP acceleration) in the QT application, and use a appsink to get preview images, do simple "sink" to one QWidget by drawing this image on the widget surface for preview (say every 50ms for 20fps). Then in other thread, we fetch the preview buffer in a fixed frequency (like every 0.5s), then feed it into the ZXing engine to decode the strings inside this image. Here are the class created inside the source code: ScannerQWidgetSink It act as a gstreamer sink for preview rendering. Init the pipeline, create a timer with timeout every 50ms. In the timer handler, we use appsink to copy the camera buffer from gstreamer, and tell the ViewfinderWidget to do update (re-draw event). ViewfinderWidget This class inherit from the QWidget, which draw the preview buffer as a QImage onto it's own surface by using QPainter. The QImage is created at the very begining with the image buffer created by the ScannerQWidgetSink. Because QImage itself does not maintain the image buffer, so the buffer must be alive during it's usage. So we keep this buffer during the ScannerQWidgetSink life cycle, copy the appsink buffer from pipeline to it for preview. MainWindow Create main window, which does not have title bar and border. Start any animation for the red line scan bar. Create instance of DecoderThread and ScannerQWidgetSink. Setup and start them. DecoderThread A infinite loop, to wait for a available buffer released by the ScannerQWidgetSink every 0.5s. Copy the buffer data to it's own buffer (imgData) to avoid any change to the buffer by sink when doing decoding. Then feed this copy of buffer into ZXing engine to get decoder result. Then show on the QLabel. Screenshot under wayland (weston) desktop: Customize Camera instance Now I use the UVC camera which pluged in the USB host, which device node is /dev/video1. If you want to use CSI or other device, please change the construction parameters for ScannerQWidgetSink(): sink = new ScannerQWidgetSink(ui->widget, QString("v4l2src device=/dev/video1")); Image resolution captured and review Change the static member value of ScannerQWidgetSink class: uint ScannerQWidgetSink::CAPTURE_HEIGHT = 480; uint ScannerQWidgetSink::CAPTURE_WIDTH = 640; Preview fps and decoding frequency Find the "framerate=20/1" strings in the ScannerQWidgetSink::GstPipelineInit(), change to your fps. You also have to change the renderTimer start timeout value in the ::StartRender(). The decoding frequency is determined by renderCnt, which determine after how many preview frames showed to feed the decoder. Main window size It's fixed size of main window, you have to change the mainwindow.ui. It's easy to do in the QtCreate Designer. FAQ Why not use CSI camera in demo? Honestly, I do not have CSI camera module, it's also DNP when you buying the board on NXP.com. So a widely used UVC camera is preferred, it's also easy for you to scan QR code on your phone, your display panel etc. Why not use QCamera to do preview and capture? The QCamera class in the Qtmultimedia component uses the camerabin2 gstreamer plugin, which create a very long pipeline for different usage of viewfinder, image capture and video encoder. Camerabin2 would eat too much CPU and memory resource, take picture and recording are very very slow. The preview of 30fps would eat about 70-80% CPU loading even I hacked it using imxvideoconvert_pxp instread of software videoconvert. Finally I give up to implement the QRScanner based on QCamera. How to make sure only one instance of QT app is running? We can use QSharedMemory to create a share memory with a unique KEY. When second instance of app is started, it would check if the share memory with this KEY is created or not. If the shm is there, it means there's already one instance running, it has to exit(). But as the QT mentioned, the QSharedMemory can not be destroyed correctly when app crashed, this means we have to handle each terminate signal, and do delete by ourselves: static QSharedMemory *gShm = NULL; static void terminate(int signum) {    if (gShm) {       delete gShm;       gShm = NULL;    }    qDebug() << "Terminate with signal:" << signum;    exit(128 + signum); } int main(int argc, char *argv[]) {    QApplication a(argc, argv);    // Handle any further termination signals to ensure the    // QSharedMemory block is deleted even if the process crashes    signal(SIGHUP, terminate ); // 1    signal(SIGINT, terminate ); // 2    signal(SIGQUIT, terminate ); // 3    signal(SIGILL, terminate ); // 4    signal(SIGABRT, terminate ); // 6    signal(SIGFPE, terminate ); // 8    signal(SIGBUS, terminate ); // 10    signal(SIGSEGV, terminate ); // 11    signal(SIGSYS, terminate ); // 12    signal(SIGPIPE, terminate ); // 13    signal(SIGALRM, terminate ); // 14    signal(SIGTERM, terminate ); // 15    signal(SIGXCPU, terminate ); // 24    signal(SIGXFSZ, terminate ); // 25    gShm = new QSharedMemory("QRScannerNXP");    if (!gShm->create(4, QSharedMemory::ReadWrite)) {       delete gShm;       qDebug() << "Only allow one instance of QRScanner";       exit(0);    } .....