For some applications, we need to reduce the CPU Frequency, but if you are not familiar with our BSP or our devices probably you need some help to do some configurations.   In this post, I will share the configuration to set up lower frequencies (100MHz, 200MHz, 400Mhz, 600MHz, 800MHz, and 1000MHz) on iMX8MP, iMX8MN, and iMX8MM.   Note: Works on Kernel 6.1.xx (not tested on oldest BSP)   1- We have to modify the PLL driver to set the proper parameters to lower frequencies. The file to modify is "clk-pll14xx.c" adding the following lines:   https://github.com/nxp-imx/linux-imx/blob/770c5fe2c1d1529fae21b7043911cd50c6cf087e/drivers/clk/imx/clk-pll14xx.c#L57   static const struct imx_pll14xx_rate_table imx_pll1416x_tbl[] = { PLL_1416X_RATE(1800000000U, 225, 3, 0), PLL_1416X_RATE(1600000000U, 200, 3, 0), PLL_1416X_RATE(1500000000U, 375, 3, 1), PLL_1416X_RATE(1400000000U, 350, 3, 1), PLL_1416X_RATE(1200000000U, 300, 3, 1), PLL_1416X_RATE(1000000000U, 250, 3, 1), PLL_1416X_RATE(800000000U, 200, 3, 1), PLL_1416X_RATE(750000000U, 250, 2, 2), PLL_1416X_RATE(700000000U, 350, 3, 2), PLL_1416X_RATE(600000000U, 300, 3, 2), + PLL_1416X_RATE(400000000U, 200, 3, 2), + PLL_1416X_RATE(200000000U, 200, 3, 3), + PLL_1416X_RATE(100000000U, 200, 3, 4), };   2- Once the pll driver has been modified, only we have to add the values on the opp-table according to the device that you will use.   2.1- For iMX 8MP:   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8mp.dtsi         a53_opp_table: opp-table { compatible = "operating-points-v2"; opp-shared; + opp-100000000 { + opp-hz = /bits/ 64 <100000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0x8a0>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-200000000 { + opp-hz = /bits/ 64 <200000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0x8a0>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-400000000 { + opp-hz = /bits/ 64 <400000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0x8a0>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-600000000 { + opp-hz = /bits/ 64 <600000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0x8a0>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-800000000 { + opp-hz = /bits/ 64 <800000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0x8a0>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-1000000000 { + opp-hz = /bits/ 64 <1000000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0x8a0>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; opp-1200000000 { opp-hz = /bits/ 64 <1200000000>;   2.2 For iMX8MM:   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8mm.dtsi     a53_opp_table: opp-table { compatible = "operating-points-v2"; opp-shared; + opp-100000000 { + opp-hz = /bits/ 64 <100000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xe>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-200000000 { + opp-hz = /bits/ 64 <200000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xe>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-400000000 { + opp-hz = /bits/ 64 <400000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xe>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-600000000 { + opp-hz = /bits/ 64 <600000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xe>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-800000000 { + opp-hz = /bits/ 64 <800000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xe>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-1000000000 { + opp-hz = /bits/ 64 <1000000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xe>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; opp-1200000000 { opp-hz = /bits/ 64 <1200000000>;   2.3- For iMX8MN:   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8mn.dtsi   compatible = "operating-points-v2"; opp-shared; + opp-100000000 { + opp-hz = /bits/ 64 <100000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xb00>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + + opp-200000000 { + opp-hz = /bits/ 64 <200000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xb00>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + + opp-400000000 { + opp-hz = /bits/ 64 <400000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xb00>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + + opp-600000000 { + opp-hz = /bits/ 64 <600000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xb00>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + + opp-800000000 { + opp-hz = /bits/ 64 <800000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xb00>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + + opp-1000000000 { + opp-hz = /bits/ 64 <1000000000>; + opp-microvolt = <850000>; + opp-supported-hw = <0xb00>, <0x7>; + clock-latency-ns = <150000>; + opp-suspend; + }; + opp-1200000000 { opp-hz = /bits/ 64 <1200000000>; opp-microvolt = <850000>;   After that, you should note the changes under Linux.   These commands return information about the system and the current settings.   • The kernel is pre-configured to support only certain frequencies. The list of frequencies currently supported can be obtained from: cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies   • To get the available scaling governors: cat /sys/devices/system/cpu/*/cpufreq/scaling_available_governors   • To check the current CPU frequency: cat /sys/devices/system/cpu/*/cpufreq/cpuinfo_cur_freq   The frequency is displayed depending on the governor set.   • To check the maximum frequency: cat /sys/devices/system/cpu/*/cpufreq/cpuinfo_max_freq   • To check the minimum frequency: cat /sys/devices/system/cpu/*/cpufreq/cpuinfo_min_freq   These commands set a constant CPU frequency:   • Use the maximum frequency: echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor   • Use the current frequency to be the constant frequency: echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor   • The following two commands set the scaling governor to a specified frequency, if that frequency is supported.   If the frequency is not supported, the closest supported frequency is used:   echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor echo <frequency> > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed    

Dynamic debug is designed to allow you to dynamically at runtime  enable/disable  kernel code to obtain additional kernel information. Currently, if ``CONFIG_DYNAMIC_DEBUG`` is set, then all ``pr_debug()``/``dev_dbg()`` and ``print_hex_dump_debug()``/``print_hex_dump_bytes()`` calls can be dynamically enabled per-callsite.    

What is a device tree? The device tree is a data structure that is passed to the Linux kernel to describe the physical devices in a system. Before device trees came into use, the bootloader (for example, U-Boot) had to tell the kernel what machine type it was booting. Moreover, it had to pass other information such as memory size and location, kernel command line, etc. Sometimes, the device tree is confused with the Linux Kernel configuration, but the device tree specifies what devices are available and how they are accessed, not whether the hardware is used. The device tree is a structure composed of nodes and properties: Nodes: The node name is a label used to identify the node. Properties: A node may contain multiple properties arranged with a name and a value. Phandle: Property in one node that contains a pointer to another node. Aliases: The aliases node is an index of other nodes. A device tree is defined in a human-readable device tree syntax text file such as .dts or .dtsi. The machine has one or several .dts files that correspond to different hardware configurations. With these .dts files we can compile them into a device tree binary (.dtb) blobs that can either be attached to the kernel binary (for legacy compatibility) or, as is more commonly done, passed to the kernel by a bootloader like U-Boot. What is Devshell? The Devshell is a terminal shell that runs in the same context as the BitBake task engine. It is possible to run Devshell directly or it may spawn automatically. The advantage of this tool is that is automatically included when you configure and build a platform project so, you can start using it by installing the packages and following the setup of i.MX Yocto Project User's Guide on section 3 “Host Setup”. Steps: Now, let’s see how to compile your device tree files of i.MX devices using Devshell. On host machine. Modify or make your device tree on the next path: - 64 bits. ~/imx-yocto-bsp/<build directory>/tmp/work-shared/<machine>/kernel-source/arch/arm64/boot/dts/freescale - 32 bits. ~/imx-yocto-bsp/<build directory>/tmp/work-shared/<machine>/kernel-source/arch/arm/boot/dts To compile, it is needed to prepare the environment as is mentioned on i.MX Yocto Project User's Guide on section 5.1 “Build Configurations”. $ cd ~/imx-yocto-bsp $ DISTRO=fsl-imx-xwayland MACHINE=<machine> source imx-setup-release.sh -b <build directory> $ bitbake -c devshell virtual/kernel (it will open a new window) On Devshell window. $ make dtbs (after finished, close the Devshell window) On host machine. $ bitbake -c compile -f virtual/kernel $ bitbake -c deploy -f virtual/kernel This process will compile all the device tree files linked to the machine declared on setup environment and your device tree files will be deployed on the next path: ~/imx-yocto-bsp/<build directory>/tmp/deploy/images/<machine> I hope this article will be helpful. Best regards. Jorge.

  Introduction   Prior to 6.1.22_2.0.0 BSP release, Bluetooth interface are based on the tty line discipline framework, so we need to use hciattach tool to enable it in the user space. From 6.1.22_2.0.0 BSP, the nxp bluetooth driver no longer needs the help of the userspace hciattach tool, and the tty port bound by bluetooth also won't be exported to the user space, so you cannot find the corresponding tty device anymore. So, you won't see the (/dev/ttymxcX), for the Bluetooth interface. All jobs has been done in the new NXP Bluetooth driver. New Method   The new NXP Bluetooth UART Driver is based on a server driver for the NXP BT serial protocol, which can enable the built-in Bluetooth device inside an NXP BT chip. This driver has a Power Save feature that will put the chip into a sleep state whenever there is no activity for 2000ms and will be woken up when any activity is to be initiated over UART.  Device Tree support The new BT framework requires adding a "bluetooth" sub node with a device compatibility string to the attached UART node in the dts file &uart1 { bluetooth { compatibility = "nxp,88w8987-bt"; fw-init-baudrate = <3000000>; #Optional. Default is considered 115200 if this parameter not defined. }; };   Note: The parameter ‘compatibility = “nxp,88w8987-bt”’ will use for 88W8987, IW416, 88Q9098, IW612 chipsets and need to change for 88W8997 with parameter ‘compatibility = “nxp,88w8997-bt”’.   Note: ’fw-init-baudrate’ parameter depends on the module vendor. The Murata and Azuere wifi modules support in BSP release uses the default value -- 115200. We strongly recommend looking at the module vendor-specific baud rate parameter. Note: For the old 88Q9098 Murata 1XL module that uses the 3Mbps by default, please add the fw-init-baudrate = <3000000> property in dts files to make it work. Enable Guide   Use wifi interface to load combo (wifi & bt) firmware and enable BT Need to load wifi driver first, then load the BT driver, otherwise, BT driver suspend/resume test will fail. This is a HW limitation, since NXP wifi and BT module use the same power control pin(W_DISABLE1#), if we don't load the wifi driver, SDIO bus will power down the wifi chip during suspend resume, which may cause the BT chip also been powered down and cannot work after resume back. So we need to load the wifi driver to make sure SDIO bus won't power down the BT chip to make sure BT functions can work during suspend resume. modprobe moal mod_para=nxp/wifi_mod_para.conf modprobe btnxpuart or insmod mlan.ko insmod moal.ko mod_para=nxp/wifi_mod_para.conf insmod btnxpuart   Unload UART Driver modprobe moal Make sure run hciconfig hci0 up or hciconfig hci0 reset or bluetootctl power on before unload btnxpuart driver. If we don't open hci0 interface, the driver cannot send change to 115200 baud rate command to BT chip, which causes the host and BT chip baud rate mismatch, the host still uses 115200bps talk to the BT chip which now use 3Mbps, it cannot work anymore. So we need to make sure open the hci0 interface before unload btnxpuart driver.   mod_para=nxp/wifi_mod_para.conf modprobe btnxpuart sleep 3 hciconfig hci0 up #Note: Need to up hci interface before unload the BT module hcitool -i hci0 cmd 3F 23 02 00 00 modprobe -r btnxpuart modprobe -r moal sleep 3​ For better reference: Please find the I.MX 8MQ Linux getting started user guide, UM11483, Chapter "7.1 Bring-up using NXP Bluetooth UART driver"  Bluetooth Deep Sleep Feature App Note AN13920, Chapter 6 Load NXP UART driver module NOTE: Please do not run the power save feature for Murata IW612 2EL Module Regards, Mario

GUI Guider version: 1.6.0 LVGL version: v8.3.5 Host software requirements: Ubuntu 20.04, Ubuntu 22.04 or Debian 12 Hardware requirements: Evaluation Kit for the i.MX 93 Applications Processor. (i.MX 93 Evaluation Kit | NXP Semiconductors) On this guide we will use the IMX-MIPI-HDMI accessory board to connect the iMX93 with a HDMI Monitor. (IMX-MIPI-HDMI Product Information|NXP) This board is usually provided with the iMX8M Mini and the iMX8M Nano.  Steps: 1. Copy your project from the folder GUI-Guider-Projects to your Linux PC.  2. Build an image for iMX93 using The Yocto Project.    a. Based on iMX Yocto Porject Users Guide set directories and download the repo $ mkdir imx-bsp-6.1.1-1.0.0 $ cd imx-bsp-6.1.1-1.0.0 $ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-langdale -m imx-6.1.1-1.0.0.xml $ repo sync Use distro fsl-imx-xwayland and select machine imx93evk and use this commnad with a build folder name: $ MACHINE=imx93evk DISTRO=fsl-imx-xwayland source ./imx-setup-release.sh - b bld-imx93evk b. Use bitbake command to start the build process. Also, add the -c populate_sdk to get the toolchain. $ bitbake imx-image-multimedia -c populate_sdk  c. Install the Yocto toolchain located on <build-folder>/tmp/deploy/sdk/.  $ sudo sh ./fsl-imx-xwayland-glibc-x86_64-imx-image-multimedia-armv8a-imx93evk-toolchain-6.1-langdale.sh d. Install ninja utility on the build host $ sudo apt install ninja-build e. For Ubuntu 20.04 and Ubuntu 22.04, copy the lv_conf.h file from lvgl-simulator to lvgl $ cp lvgl-simulator/lv_conf.h lvgl/ f. Change the interpreter on build.sh from #!/bin/sh to #!/bin/bash. This is an important step! g. Then, enter to linux folder and use the following commands to make build.sh executable $ dos2unix build.sh $ chmod +x build.sh h. Execute the build.sh $ ./build.sh i. Copy the binary to the iMX93 using a USB or SCP.  2. On the target iMX93 follow these steps. a. On Uboot, use fatls interface device:partition fatls mmc 0:1 (Device 0 : Partition 1) With this command, we will be able to list device tree files. => fatls mmc 0:1 b. Select imx93-11x11-evk-rm67199.dtb and use the command editenv fdtfile  => editenv fdtfile Output example edit: imx93-11x11-evk-rm67199.dtb c. In edit command line put the selected device tree .dtb d. Use saveenv command to save environment and continue with the boot process. e. Finally, run the GUI Application $ ./gui_guider&   I hope this article will be helpful. Best regards, Brian.

Hello everyone, this document will share an step by step guide of the configuration needed in a Linux PC to compile the SDK examples we provide, as well as how to download them in an easy way. Requirements: I.MX 8M Mini EVK SDK package (for i.MX8MM) UUU tool First step would be to get the SDK package, this include documentation and code, which is available at the MCUXpresso builder webpage: https://mcuxpresso.nxp.com/en/welcome Click on the select a development board and select the package for your development kit or the i.MX MPU   This guide is focused on Linux build so will select GCC package and Linux host PC as the environment. Click on build and wait for the SDK package to be ready for download. Note1: Click on select all if the whole middleware package is desired Note2: it is possible to select each middleware that are desired. On new window select download SDK Select on new pop-up window download both SDK and documentation Read and accept EULA so the download start Decompress the package using the following command: $ tar -xvzf ~/SDK_2_13_0_EVK-MIMX8MM.tar.gz -C ~/SDK_2_13_0_EVK-MIMX8MM Next will be to download the GCC from the ARM webpage, gcc-arm-none-eabi-10.3-2021.10-x86_64-linux.tar.bz2 https://developer.arm.com/downloads/-/gnu-rm Note that the GCC version used is based on the minimum version required, since this was tested and supported, this could be found within the SDK documentation (~/SDK_2_13_0_EVK-MIMX8MM/docs/MCUXpresso SDK Release Notes for EVK-MIMX8MM) Once downloaded we can decompress and configure the environment: $ tar -xf gcc-arm-none-eabi-10.3-2021.10-x86_64-linux.tar.bz2 $ export ARMGCC_DIR=~/gcc-arm-none-eabi-10.3-2021.10 $ export PATH=$PATH:~/gcc-arm-none-eabi-10.3-2021.10 $ sudo apt-get install cmake  Check the version >= 3.0.x $ cmake --version Once this is done we enter the path of the example of our choice and compile using the script, as necessary using debug, release or all. $ cd ~/SDK_2_13_0_EVK-MIMX8MM/boards/evkmimx8mm/demo_apps/hello_world/armgcc $./build_release.sh The binary (elf and bin) will be found inside the folder according to whether we use debug or release script. For this example we used release script: $ cd release Once builded we can move/download the binaries from the Linux host PC to the board by using the UUU tool with the command fat_write #### we put the board in fastboot mode by entering the command in the uboot terminal fastboot 0 #### From the Linux terminal introduce the UUU command to  download to the FAT partition of the eMMC of the baord: ## For rproc it is needed the .elf binary ## $ uuu -v -b fat_write hello_world.elf mmc 0:1 hello_world.elf ## For bootaux it is needed the .bin binary ## $  uuu -v -b fat_write hello_world.bin mmc 0:1 hello_world.bin Once with the binaries in the FAT partition of the SD/eMMC of our board we can make the necessary modifications (device tree/bootargs) to test the Cortex-M examples. For any question regarding this document, please create a community thread and tag me if needed. Saludos/Regards, Aldo.

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

Installing the new release (Ubuntu 22.04) was detected some NXP boards as iMX8MNEVK, iMX8MM-EVK, iMX8MP-EVK and iMX8ULP-EVK had an issue with the WIFI module that basically it does not initialize at boot. Remember, the supported WIFI modules in Ubuntu 22.04 in the EVKs are the following:       • NXP 88W8987       • NXP 88W9098       • NXP 88W8997       • NXP IW416       • NXP 88W8801       • NXP IW612 To initialize the WIFI module of NXP EVKs in Ubuntu 22.04 you can set the following command in console:   sudo modprobe moal mod_para=nxp/wifi_mod_para.conf   That command find the correct driver for our WIFI module and then initialize it, but this only works when Ubuntu is working and if you reset the EVK you need to set the command again.   The definitive solution is create a custom startup script as a service:   Step 1: Go to etc/systemd/system   cd etc/systemd/system   Step 2: In this directory create a new file with the name of your preference but the extension must be .service. You can do it with nano or vim: sudo nano or sudo vim   The file must contain: [Unit] Description=”Wifi Start” [Service] ExecStart=sudo modprobe moal mod_para=nxp/wifi_mod_para.conf [Install] WantedBy=multi-user.target   Now save the file, in my case the name was wifi_start.service.   Step 3: Now we need to enable the script in the startup/boot sequence following the command: sudo systemctl enable wifi_start.service   Remember in wifi_start.service is the name as you saved your file.   Finally, each time you boot your board, the WIFI module will initialize automatically.   Boards tested: iMX8MN (With WIFI module NXP 88W8987) iMX8MM (With WIFI module NXP 88W8987) iMX8MP (With WIFI module NXP 88W8997) iMX8ULP (With WIFI module NXP IW416)  

Hello everyone, We have recently migrated our Source code from CAF (Codeaurora) to Github, so i.MX NXP old recipes/manifest that point to Codeaurora eventually will be modified so it points correctly to Github to avoid any issues while fetching using Yocto. Also, all repo init commands for old releases should be changed from: $ repo init -u https://source.codeaurora.org/external/imx/imx-manifest -b <branch name> [ -m <release manifest>] To: $ repo init -u https://github.com/nxp-imx/imx-manifest -b <branch name> [ -m <release manifest>] This will also apply to all source code that was stored in Codeaurora, the new repository for all i.MX NXP source code is: https://github.com/nxp-imx For any issues regarding this, please create a community thread and/or a support ticket. Regards, Aldo.

PCIE IP on i.MX8MM and i.MX8MP is same, customer can follow PCIE test Application note to do compliance test, if eye diagram failed, they can fine turn corresponding regs below: iMX8MMRM.pdf IMX8MPRM.pdf GEN1:             GEN2:                 Related code in kernel Phy-fsl-imx8-pcie.c (kernel-source\drivers\phy\freescale)    3794      2020/11/4 static int imx8_pcie_phy_init(struct phy *phy) { ……          /* Configure TX drive level  */        writel(0x2d, imx8_phy->base + 0x404);          return 0; }   Thanks Lambert

current bsp fixed the lvds pixel clock up to 74.25Mhz for single channel and 148.5Mhz for dual channel, if customer wants to know why and how to change it, maybe can refer to the enclosed file, hope helpful for you

On i.MX8MP EVK, image is downloaded into eMMC/SD via OTG1, if customer wants to enable USB OTG2 on i.MX8MP for uuu tool. Pls find modification as attached.

1. Intro   This document contains instructions to run run the SAI low power audio demo on the i.MX 8M Plus EVK. Here, the  RPSMG to allows audio to be passed from the A53 cluster running Linux to the M7 core. The latter controls the on board WM8960 audio codec,  which is connected to a 3.5 mm audio jack that allow us to play music using headphones. I will show the necessary steps to make the demo work and will add some GStreamer examples to demonstrate the demo's capabilities.   TBD: update this with a nice diagram that depicts the A53 and M7 RPMSG channel. 2. Requirements   Hardware  MX 8M Plus EVK Headphones with 3.5 mm audio jack Type-C power supply for i.MX 8M Plus EVK Micro USB to USB adapter cable Software  A recent prebuilt Linux BSP image from NXP.com ( we tested this on 5.15.35 and 5.15.5 releases) Windows 10 or Ubuntu 20.04 Workstation MCUXpresso SDK for i.MX 8M Plus ( available from:  Welcome | MCUXpresso SDK Builder (nxp.com)) 3. Reference documentation for this example   MCUXpresso SDK   [1] Getting Started with MCUXpresso SDK for EVK-MIMX8MP     Available within the MCUXpresso SDK package:  \{INSTALL PATH}\SDK_X_X_X_EVK-MIMX8MP\docs    [2] SAI low power audio README file Contains instructions for the SAI Low Power Audio Demo.  Available within the MCUXpresso SDK package: \{INSTALL PATH}\SDK_X_X_X_EVK-MIMX8MP\boards\evkmimx8mp\demo_apps\sai_low_power_audio   4. Downloading a pre-built Linux BSP image for the i.MX 8M Plus   I will make use of the prebuilt Linux Image for the i.MX 8M Plus EVK for demonstrating the demo works.  At the moment of writing this time, I used the 5.15.32 release, although there are older releases like 5.10.5 that I tested and proved to work with no issues. This SAI Low Power Audio Demo shall work for other processors on the i.MX 8M family. Although specific instructions ( e.g. load address for M-core binary load) might require some adaptation. For M-core load address, please refer to the specific MCUXpresso SDK documentation for each processor. The prebuilt Linux image (5.15.32) for the i.MX 8M Plus EVK can be downloaded from here: https://www.nxp.com/webapp/Download?colCode=L5.15.32_2.0.0_MX8MP&appType=license You can download other releases from here: Embedded Linux for i.MX Applications Processors | NXP Semiconductors . Select a version and a board and select download. 5. Flashing the BSP image   If you are using an Ubuntu 20.04 workstation, I recommend you to flash the image using dd. For this, you can refer to the i.MX Linux User's Guide: Section - 4.3.2 Copying the full SD card image - https://www.nxp.com/docs/en/user-guide/IMX_LINUX_USERS_GUIDE.pdf sudo dd if=.wic of=/dev/sdx bs=1M && sync NOTE: when using dd, ALWAYS, double check the of device that you are about to writing. Messing up with another location or partition will harm your system   If you are following this document on a Windows machine: You can use the Universal Update Utility (UUU) to flash your image on either the board's eMMC or SD card. Document named UUU.pdf shall serve as your reference guide for further instructions and flashing examples. It is available along with UUU binary here: https://github.com/NXPmicro/mfgtools/releases Two examples are shown below for your convenience:                                     SD card flash                                                 uuu -b sd_all bootloader rootfs.sdcard.bz2                                     eMMC flash                                                 uuu -b emmc_all bootloader rootfs.sdcard.bz2        uuu uuu.auto NOTE: UUU is also compatible with Ubuntu NOTE: there are other engineers who like to use BalenaEtcher for flashing their BSP images. I have tested it and works on both Ubuntu and Windows 10 machines.   6. Preparing the BSP and booting up M7 core  using U-Boot   I am writing this upon the instructions contained on the README file for the low power audio example  [2]. Instructions ready to copy and paste will follow:   Instruct U-Boot to pass to the kernel the rpmsg device tree to enable communication between the A53 cluster and the M7 one: u-boot=>setenv fdtfile imx8mp-evk-rpmsg.dtb u-boot=>saveenv Load the M7 example: u-boot=>setenv mmcargs 'setenv bootargs ${jh_clk} console=${console} root=${mmcroot} snd_pcm.max_alloc_per_card=134217728' u-boot=>saveenv Now, we need to load the M4 with the demo. Refer to [1] for further information. If running the BSP on an SD card, make sure the example binary is listed on the boot partition as follows: fatls mmc 1:1 You shall see something similar to this:             imx8mp_m7_TCM_sai_low_power_audio.bin Open the serial terminal emulator for the M7. Out of the fourth ports listed when we plug the i.MX 8M Plus serial debug cable to the PC, the M7 is typically the last one listed.   All the serial ports available to the workstation when the i.MX 8M Plus serial cable is connected to it. NOTE: you may require to install addtitional COM drivers if you are running on Windows. I like doing the previous step so I can see the result of the next commands issued in U-boot to load the M7 image. fatload mmc 1:1 0x48000000 imx8mp_m7_TCM_sai_low_power_audio.bin; cp.b 0x48000000 0x7e0000 20000; bootaux 0x7e0000 Here is an screenshot that shows how the U-Boot's response should look: U-Boot response when loading the SAI low power audio example to the Cortex M7 That should have prompted the following message on the M7 terminal: M7-core is up!   Now, let’s move to user space! u-boot=> boot 7. Testing the example using a simple GStreamer pipeline   As soon as the O.S. finishes booting. We can see that M7 terminal prompts the following: M7 is now in STOP mode; waiting for some audio to beat the room! Confirm that the WM8960 is listed as audio card as follows: cat /proc/asound/cards             Listing avaialable audio cards. WM8960 should be present. Make note of the list. The wm8960 is listed a the third sound card. This is where I like to differ a bit from [2] and I suggest a quicker test in case of not having an audio file ready. We just simply use GStreamer to play an audiotest source. Please make sure to plug in your headphones onto the board’s 3.5 mm jack before.   The following GStreamer pipeline is using the WM8960 as an audiosink.  gst-launch-1.0 audiotestsrc ! alsasink device=hw:3   NOTE: please be cautious and not put the headphones directly in your head at the first attempt. The sound can be too loud to some people. This is what you should see on the M7 side: Stop the GStreamer pipeline issuing CTRL + C. M7 shall warn you about that: NOTE: you can use the aplay command to play audio as shown on [2]. However, I consider using a testsrc is much quicker and flexible for a quick test.  8. Additional information   Feel free to go ahead and tweak the GStreamer pipeline to change audio test source properties. audiotest src. This command will let you know the available options:            gst-inspect-1.0 audiotestsrc                         NOTE: you can navigate through the displayed list using the “d”key. Press “q’’ to quit. For example:     For example, I am reproducing sound using a different setup based on the list above: gst-launch-1.0 audiotestsrc freq=4000 volume=0.8 wave=8 ! alsasink device=hw:3 9.  Errata and future updates   TBD:     Add an example on how to define the default audio card and play the audio either using gst-play or building the pipeline using filesrc Comment on the limitations of the M7 core regarding sample rate and audio formats  

some industry customer to use i.MX8MM will use RMII to link the 100Mhz ethernet phy and wish to use our i.mx8mm output 50Mhz reference clock to external phy to save a crystal, this doc and patch explain how to support it. SW: Linux BSP 5.10.17. HW: i.MX8MM LPDDR/DDR EVK board. 中文版本为一个完整的如何支持一个100Mhz以太网PHY  

BSP: L5.15.5_1.0.0 Platform: i.MX8MPlus EVK Background   The function lpddr4_mr_read in BSP always return zero and this casue the customer can't use it to read MR registers in DRAM. This is a simple demo for reading MR registers. Patch Code   diff --git a/arch/arm/include/asm/arch-imx8m/ddr.h b/arch/arm/include/asm/arch-imx8m/ddr.h index 0f1e832c03..fd68996a23 100644 --- a/arch/arm/include/asm/arch-imx8m/ddr.h +++ b/arch/arm/include/asm/arch-imx8m/ddr.h @@ -721,6 +721,8 @@ int wait_ddrphy_training_complete(void); void ddrphy_init_set_dfi_clk(unsigned int drate); void ddrphy_init_read_msg_block(enum fw_type type); +unsigned int lpddr4_mr_read(unsigned int mr_rank, unsigned int mr_addr); + void update_umctl2_rank_space_setting(unsigned int pstat_num); void get_trained_CDD(unsigned int fsp); diff --git a/board/freescale/imx8mp_evk/spl.c b/board/freescale/imx8mp_evk/spl.c index 33bbbc09ac..85e40ffbbe 100644 --- a/board/freescale/imx8mp_evk/spl.c +++ b/board/freescale/imx8mp_evk/spl.c @@ -150,6 +150,40 @@ int board_fit_config_name_match(const char *name) return 0; } #endif +void lpddr4_get_info() +{ + int i = 0, attempts = 5; + + unsigned int ddr_info = 0; + unsigned int regs[] = { 5, 6, 7, 8 }; + + for(i = 0; i < ARRAY_SIZE(regs); i++){ + unsigned int data = 0; + data = lpddr4_mr_read(0xF,regs[i]); + ddr_info <<= 8; + ddr_info += (data & 0xFF); + switch (i) + { + case 0: + printf("DRAM INFO : Manufacturer ID = 0x%x",ddr_info); + if(ddr_info & 0Xff) + printf(", Micron\n"); + break; + case 1: + printf("DRAM INFO : Revision ID1 = 0x%x\n",ddr_info); + break; + case 2: + printf("DRAM INFO : Revision ID2 = 0x%x\n",ddr_info); + break; + case 3: + printf("DRAM INFO : I/O Width and Density = 0x%x\n",ddr_info); + break; + default: + break; + } + } + +} void board_init_f(ulong dummy) { @@ -187,6 +221,8 @@ void board_init_f(ulong dummy) /* DDR initialization */ spl_dram_init(); + + lpddr4_get_info(); board_init_r(NULL, 0); } diff --git a/drivers/ddr/imx/imx8m/ddrphy_utils.c b/drivers/ddr/imx/imx8m/ddrphy_utils.c index 326b92d784..f45eeaf552 100644 --- a/drivers/ddr/imx/imx8m/ddrphy_utils.c +++ b/drivers/ddr/imx/imx8m/ddrphy_utils.c @@ -194,8 +194,15 @@ unsigned int lpddr4_mr_read(unsigned int mr_rank, unsigned int mr_addr) tmp = reg32_read(DRC_PERF_MON_MRR0_DAT(0)); } while ((tmp & 0x8) == 0); tmp = reg32_read(DRC_PERF_MON_MRR1_DAT(0)); - tmp = tmp & 0xff; reg32_write(DRC_PERF_MON_MRR0_DAT(0), 0x4); + + while (tmp) { //try to find a significant byte in the word + if (tmp & 0xff) { + tmp &= 0xff; + break; + } + tmp >>= 8; + } return tmp; }     Test Result  

  Test environment   i.MX8MP EVK LVDS0 LVDS-HDMI  bridge(it6263) L5.15.5_1.0.0 Background   Some customers need show logo using LVDS panel. Current BSP doesn't support LVDS driver in Uboot. This patch provides i.MX8MPlus LVDS driver support in Uboot. If you want to connect it to LVDS panel , you need port your lvds panel driver like  simple-panel.c   Update [2022.9.19] Verify on L5.15.32_2.0.0  0001-L5.15.32-Add-i.MX8MP-LVDS-driver-in-uboot 'probe device is failed, ret -2, probe video device failed, ret -19' is caused by below code. It has been merged in attachment. // /* Only handle devices that have a valid ofnode */ // if (dev_has_ofnode(dev) && !(dev->driver->flags & DM_FLAG_IGNORE_DEFAULT_CLKS)) { // /* // * Process 'assigned-{clocks/clock-parents/clock-rates}' // * properties // */ // ret = clk_set_defaults(dev, CLK_DEFAULTS_PRE); // if (ret) // goto fail; // }   [2023.3.14] Verify on L5.15.71 0001-L5.15.71-Add-i.MX8MP-LVDS-support-in-uboot   [2023.9.12] For some panel with low DE, you need uncomment CTRL_INV_DE line and set this bit to 1. #include <linux/string.h> @@ -110,9 +111,8 @@ static void lcdifv3_set_mode(struct lcdifv3_priv *priv, writel(CTRL_INV_HS, (ulong)(priv->reg_base + LCDIFV3_CTRL_SET)); /* SEC MIPI DSI specific */ - writel(CTRL_INV_PXCK, (ulong)(priv->reg_base + LCDIFV3_CTRL_CLR)); - writel(CTRL_INV_DE, (ulong)(priv->reg_base + LCDIFV3_CTRL_CLR)); - + //writel(CTRL_INV_PXCK, (ulong)(priv->reg_base + LCDIFV3_CTRL_CLR)); + //writel(CTRL_INV_DE, (ulong)(priv->reg_base + LCDIFV3_CTRL_CLR)); }      

Useful information about push buttons.   Physical level.            When there is a change of voltage level on P0-P7 pins, PCA9555PW will generate interrupt on INT pin. The driver (running on SoC) can read the status of P0-P7 pins via I2C (SCL/SDA pins) and generate separate interrupts for each of P0-P7 pins. This is why this driver acts as interrupt controller. Consider next configuration:        One push button changes level on P4 pin, tempting PCA9555PW to generate interrupt. Interrupt from PCA9555PW is connected to GPIO5 IP-core (inside of SoC), and it uses line #9 of that GPIO5 module to notify CPU about interrupt. So we can say that PCA9555PW is cascaded to GPIO5 controller. GPIO5 also acts as interrupt controller, and it's cascaded to GIC interrupt controller.   Device tree properties.   The meaning of properties is as follows: interrupt-controller  property defines that device generates interrupts; it will be needed further to use this node as interrupt-parent in each push button node. #interrupt-cells defines format of interrupts property; in our case it's 2 : 1 cell for line number and 1 cell for interrupt type interrupt-parent and interrupts properties are describing interrupt line connection   Interrupt handling.   CPU now is in interrupt context in GIC interrupt handler. From gic_handle_irq() it calls handle_domain_irq() , which in turn calls generic_handle_irq() . See Documentation/gpio/driver.txt for details. Now we are in SoC's GPIO controller IRQ handler. SoC's GPIO driver also calls generic_handle_irq() to run handler, which is set for each particular pin. See for example how it's done in omap_gpio_irq_handler() . Now we are in PCA9555PW IRQ handler. PCA9555PW IRQ handler calls handle_nested_irq() . Finally, gpio_keys_gpio_isr() is called.      The following steps allow you to enable rgb led's and push buttons on 8MIC-RPI-MX8 board with i.MX 8M Mini Applications Processor Evaluation Kit (EVKB). You have to use a led driver and change the device tree. On the Host. Cloning the Linux kernel repository.   Clone the i.MX Linux Kernel repo to the home directory. cd ~ git clone https://source.codeaurora.org/external/imx/linux-imx This guide will use the following commit which corresponds to Kernel 5.10.35-2.0. cd linux-imx/ git checkout -b RGB ef3f2cfc6010 Patching the device tree.   Download the "0001-Enable-RGB-LED-s-and-push-buttons-on-8MIC-RPI-MX8-bo.patch" file attached to this post and copy it into linux-imx directory, then apply the patch. cp 0001-Enable-RGB-LED-s-and-push-buttons-on-8MIC-RPI-MX8-bo.patch ~/linux-imx/ cd ~/linux-imx/ patch < 0001-Enable-RGB-LED-s-and-push-buttons-on-8MIC-RPI-MX8-bo.patch When prompted, select the file to patch: File to patch: arch/arm64/boot/dts/freescale/imx8mm-evk-8mic-revE.dts patching file arch/arm64/boot/dts/freescale/imx8mm-evk-8mic-revE.dts Then setup your toolchain, for example: source /opt/fsl-imx-wayland/5.10-hardknott/environment-setup-cortexa53-crypto-poky-linux Generate config file. make imx_v8_defconfig Compile the device tree. make freescale/imx8mm-evk-8mic-revE.dtb Copy the .dtb file to the EVK, for example with scp: scp imx8mm-evk-8mic-revE.dtb root@<EVK_IP>:/home/root Alternatively, you may copy the .dtb file directly to the FAT32 partition where the Kernel and Device Tree files are located. Compiling the Led driver.   Obtain the leds-pca995x.h file in the next site: https://github.com/TechNexion/linux-tn-imx/blob/tn-imx_5.4.70_2.3.0-stable/include/linux/platform_data/leds-pca995x.h  Copy it into the next path: cp leds-pca995x.h ~/linux-imx/include/linux Create a new directory. mkdir ~/linux-imx/PCA9955 Create a makefile. cd ~/linux-imx/PCA9955 vim Makefile   KERNEL_ROOT?=~/linux-imx obj-m += leds-pca995x.o all: make -C $(KERNEL_ROOT) M=$(PWD) modules clean: make -C $(KERNEL_ROOT) M=$(PWD) clean   Press the key "Esc" and then: :wq Obtain the leds-pca995x.c file in the next site: https://github.com/TechNexion/linux-tn-imx/blob/tn-imx_5.4.70_2.3.0-stable/drivers/leds/leds-pca995x.c Copy it into the next path: cp leds-pca995x.c ~/linux-imx/PCA9955 Obtain 0001-PCA9955BTW.patch file and copy it into the next path: cp 0001-PCA9955BTW.patch ~/linux-imx/PCA9955 Apply the patch. patch < 0001-PCA9955BTW.patch Then setup your toolchain, for example: source /opt/fsl-imx-wayland/5.10-hardknott/environment-setup-cortexa53-crypto-poky-linux Generate .ko file. cd ~/linux-imx/PCA9955 make all Copy the .ko file to the EVK, for example with scp: scp leds-pca995x.ko root@192.168.100.105:/home/root NOTE: The linux version of .ko file must be the same as EVK. On the EVK. Switching the device tree.   To copy the updated device tree to the corresponding partition, first create a directory. mkdir Partition_1 Mount the partition one. mount /dev/mmcblk1p1 Partition_1/ Copy or move the device tree into partition one. cp imx8mm-evk-8mic-revE.dtb Partition_1/ Reboot the board. reboot Stop on u-boot and modify the .dtb file to use the device tree for 8mic board. u-boot=> editenv fdtfile edit: imx8mm-evk-8mic-revE.dtb u-boot=> saveenv Saving Environment to MMC... Writing to MMC(1)... OK u-boot=> boot Installing a led driver.   Execute the following command to load the led driver into the kernel. insmod leds-pca995x.ko And you will see something like: [ 249.359103] leds_pca995x: loading out-of-tree module taints kernel. [ 249.366864] ALL [ 249.368740] ALL 0 [ 249.370667] ALL 1 [ 249.372609] ALL 2 [ 249.374536] ALL 2 [ 249.376475] ALL 2 [ 249.378401] ALL 2 [ 249.380338] ALL 2 [ 249.382264] ALL 2 [ 249.384202] ALL 2 [ 249.386127] ALL 2 [ 249.388063] ALL 2 [ 249.389989] ALL 2 [ 249.391913] ALL 2 [ 249.393847] ALL 2 [ 249.395774] ALL 2 [ 249.397709] ALL 2 [ 249.399635] ALL 2 [ 249.401568] ALL 2 [ 249.403496] ALL 3 Turning on a Led.   If you changed the device tree, you can turn on a led with the following command: echo 250 > /sys/class/leds/pca995x\:blue0/brightness To turn off a led: echo 0 > /sys/class/leds/pca995x\:blue0/brightness The red, blue and green leds can be turned on at different intensities provided. Testing the push buttons.   If you changed the device tree, you can test the push buttons with the following command: evtest Select the correct number: No device specified, trying to scan all of /dev/input/event* Available devices: /dev/input/event0: 30370000.snvs:snvs-powerkey /dev/input/event1: sw_keys /dev/input/event2: gpio_ir_recv Select the device event number [0-2]: 1 And you will see: Input driver version is 1.0.1 Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100 Input device name: "sw_keys" Supported events: Event type 0 (EV_SYN) Event type 1 (EV_KEY) Event code 67 (KEY_F9) Event code 113 (KEY_MUTE) Event code 114 (KEY_VOLUMEDOWN) Event code 115 (KEY_VOLUMEUP) Properties: Testing ... (interrupt to exit) Event: time 1642457988.1642457988, type 1 (EV_KEY), code 114 (KEY_VOLUMEDOWN), value 1 Event: time 1642457988.1642457988, -------------- SYN_REPORT ------------ Event: time 1642457988.1642457988, type 1 (EV_KEY), code 114 (KEY_VOLUMEDOWN), value 0 Event: time 1642457988.1642457988, -------------- SYN_REPORT ------------

This is a quick article focused on how to add the support of SFTP on the i.MX devices using Yocto to add that packages.   Refer to the pdf attached.

This is a quick article focused on how to add the support of the ssh on the i.MX devices using Yocto to add that packages.   Refer to the pdf attached.

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