Since LF_v5.10.52-2.1.0 crypto_af_alg blackkey demo “caam-decrypt” becomes default in release. You can try it with binary demo release image. The demo is using black key to decrypt data. This document goes more detail based on BSP release document i.MX Linux® User's Guide, Rev. LF5.10.52_2.1.0, 15 October 2021 10.6 crypto_af_alg application support   HW: i.MX8MM EVK SW: LF_v5.10.52-2.1.0_images_IMX8MMEVK binary demo image PC side: 1. generate key and iv by openssl echo 12345 | openssl enc -aes-256-cbc -k - -P -md sha1 -pbkdf2 salt=1982686A7BACEE4D key=D84041EC14BB28543E8545BEB094FE643B5BC1345C31CD576BC708A1559FBD2D iv =F950CACE80F76F0AC00D9C8762B3A5C9 2. encrption by openssl echo "For test caam-decrypt" | openssl enc -e -aes-256-cbc -in - -out test.txt.enc -K D84041EC14BB28543E8545BEB094FE643B5BC1345C31CD576BC708A1559FBD2D -iv F950CACE80F76F0AC00D9C8762B3A5C9 3. decryption by openssl openssl enc -d -aes-256-cbc -in test.txt.enc -out - -K D84041EC14BB28543E8545BEB094FE643B5BC1345C31CD576BC708A1559FBD2D -iv F950CACE80F76F0AC00D9C8762B3A5C9 4. convert key and iv to plian txt for caam-decrypt. echo F950CACE80F76F0AC00D9C8762B3A5C9| xxd -r -p > fromopenssl.iv.txt echo D84041EC14BB28543E8545BEB094FE643B5BC1345C31CD576BC708A1559FBD2D| xxd -r -p > fromopenssl.key.txt 5. prepare data for caam-decrypt cat fromopenssl.iv.txt test.txt.enc > data.caam-decrypt.enc note: the format for with blackkey AES Encrypted file format 16 Octets - Initialization Vector (IV) is an input to encryption algorithm. nn Octets - Encrypted message (for AES-256-CBC, it must be multiple of 16) 6. send fromopenssl.key.txt and data.caam-decrypt.enc to the board on i.MX8MM evk board 1. generate blackkey blob caam-keygen create blackkey ecb -t $(cat fromopenssl.key.txt) 2. delete fromopenssl.key.txt 3. test decryption by caam-decrypt with blackkey caam-decrypt /data/caam/blackkey.bb AES-256-CBC data.caam-decrypt.enc data.caam-decrypt.dec root@imx8mmevk:/# cat data.caam-decrypt.dec For test caam-decrypt  

Materials: i.MX8M Plus EVK Rev. A USB cable type-C USB cable type-B AC Adapter EA1045CR Micro SD (Optional) 88W8997-based wireless modules Software: Yocto Project Mobaxterm Personal Edition v20.2 Build 4296 This test was done on an i.MX8M Plus EVK with Linux 5.10. Hardknott.   To achieve this, you need to identify your WI-FI module and look for the necessary drivers for that module, in my case I am using the 88W8997 module that comes with the i.MX8M Plus, but you can select any other WI-FI module you want.   In my case I build a basic image on Yocto, following the Yocto users guide, I bitbake just the core boot image that allows me to boot the i.MX8M plus. Deploy your image on an SD or eMMC. These instructions apply to SD and MMC cards although for brevity, and usually, only the SD card is listed. For a Linux image to be able to run, four separate pieces are needed: Linux OS kernel image (zImage/Image) Device tree file (*.dtb) Bootloader image Root file system (i.e., EXT4)   The Yocto Project build creates an SD card image that can be flashed directly. This is the simplest way to load everything needed onto the card with one command. A .wic image contains all four images properly configured for an SD card. The release contains a pre-built .wic image that is built specifically for the one board configuration. It runs the Wayland graphical backend. It does not run on other boards unless U-Boot, the device tree, and rootfs are changed. When more flexibility is desired, the individual components can be loaded separately, and those instructions are included here as well. An SD card can be loaded with the individual components one-by-one or the .wic image can be loaded and the individual parts can be overwritten with specific components. The rootfs on the default .wic image is limited to a bit less than 4 GB, but re-partitioning and re-loading the rootfs can increase that to the size of the card. The rootfs can also be changed to specify the graphical backend that is used. Carry out the following command to copy the SD card image to the SD/MMC card. Change sdx below to match the one used by the SD card. $ sudo dd if=<image name>.wic of=/dev/sdx bs=1M && sync The entire contents of the SD card are replaced. If the SD card is larger than 4 GB, the additional space is not accessible. As this build does not contain the driver integrated we need to add it manually on Linux user space. Follow these instructions to load the driver modules and bring up the 88W8987-based wireless module, more info can be found on the next link: https://www.nxp.com/products/wireless/wi-fi-plus-bluetooth/2-4-5-ghz-dual-band-2x2-wi-fi-5-802-11ac-plus-bluetooth-5-3-solution:88W8997?tab=Documentation_Tab   Use the nano editor included in the pre-built image to edit and verify the module parameters in the wifi_mod_para.conf configuration file.   Add the following lines to the configuration file: PCIE8997 = { cfg80211_wext=0xf wfd_name=p2p max_vir_bss=1 cal_data_cfg=none drv_mode=7 ps_mode=2 auto_ds=2 fw_name=nxp/pcieuart8997_combo_v4.bin } Load the modules in the kernel:   Verify the kernel debug messages in the command output   Verify that the module is now visible to the system:     Now that the module is ready to work, we need to enable it, in my case the Wi-Fi is named mlan0, it could vary on other Linux systems.   In the case you need to see which networks are available you can scan it and select the one you need.   Identify your network and add it to the  WPA supplicant file:     Associate the Wi-Fi with config:   Check if you have right SSID associated:   Use DHPC to get the IP   Ping any public site you know to check the network.   In the case you have a Temporary failure in name resolution you will need to change the default DNS that was assigned by DHCP:     Modify /etc/resolv.conf file and add the DNS of your preference, for my case I add the one that uses Google, as they have access to the most common web pages.   And with that should work.    

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.

Here is the docment about arm64 kernel booting process, which is helpful for us to port kernel. It include the bootloader protocol, virtual memory layout, dtb, memory init, irq init, timer init and so on, please take the attachment for details. vmlinux ELF vmlinux.lds.S head.S __create_page_tables __cpu_setup __primary_switch init_task IRQ Vectors Start_kernel setup_arch paging_init bootmem_init psci_dt_init mm_init sched_init init_IRQ time_init rest_init You can refer the diagram show as below:  

Following OTA in Android User Guide would have HASH verification error: update_engine: [0913/085233.421711:ERROR:delta_performer.cc(1140)] Expected: sha256|hex = 685B998E4308F20FEA83D97E60222121FFE27983F013AED5C203709E139AE9DB update_engine: [0913/085233.421760:ERROR:delta_performer.cc(1143)] Calculated: sha256|hex = B1025634138BF2B5378196E364350E1E5FCA126DEE0990A592290CEBFADC3F8B The OTA process that produced the error: * After compiling the images according to the user guide, burn the images in the /out directory into the board * Then build the first target file according to 7.1.1 Building target files, such as PREVIOUS-target_files.zip * Modify part of the code to build the second target file, such as NEW-target_files.zip: * Make a differential upgrade package and perform differential OTA The root cause of the error caused by the above steps: Differential OTA requires that the onboard system.img must be the system.img generated when the target files are created for the first time. Only in this way can the correct hash value be calculated. When we execute the following command to make target files make target-files-package -j4 Will repackage a copy of system.img in the /out directory and this system.img does not meet the requirements. The system.img used by the differential package must be system.img in out/target/product/evk_8mm/obj/PACKAGING/systemimage_intermediates/. Therefore, the system.img we burned in the first step did not meet the requirements, resulting in hash verification errors. Solution 1: After the first step of programming, do a full update. When using the make otapackage -j4 command, a target_files.zip file will also be generated, which we will regard as PREVIOUS-target_files.zip. Modify part of the code and make NEW-target_files.zip. Finally, the differential upgrade can be successful. Solution 2: After finishing the first target_files.zip, copy the system.img in out/target/product/evk_8mm/obj/PACKAGING/systemimage_intermediates/ to the out/target/product/evk_8mm directory, and then use uuu Perform programming. After burning and writing, make the second target_files.zip, and finally you can upgrade by differential.

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

Important: If you have any questions or would like to report any issues with the DDR tools or supporting documents please create a support ticket in the i.MX community. Please note that any private messages or direct emails are not monitored and will not receive a response. These are detailed programming aids for the registers associated with DRAM initialization (LPDDR3 and LPDDR2). The last work sheet tab in the tool formats the register settings for use with the ARM DS5 debugger. It can also be used with the windows executable for the DDR Stress Test (note the removal of debugger specific commands in this tab). These programming aids were developed for internal NXP validation boards.   This tool serves as an aid to assist with programming the DDR interface of the i.MX 7ULP and is based on the DDR initialization scripts developed for NXP boards and no guarantees are made by this tool.   The following are some general notes regarding this tool: The default configuration for the tool is to enable bank interleaving. Refer to the "How To Use" tab in the tool as a starting point to use this tool. The tool can be configured for one of the two memory types supported by the i.MX 7ULP.  Nevertheless, two separate programming aids are provided based on the DRAM type: LPDDR3 and LPDDR2.  Therefore, you may use the tool pre-configured for your desired memory type as a starting point. Some of the CCM programming at the beginning of the DRAM initialization script (in the "DStream .ds file" tab) were automatically generated and in very few cases may involve writing to reserved bits, however, these writes to reserved bits are simply ignored. Note that in the "DStream .ds file" tab there are DS5 debugger specific commands that should be commented out or removed when using the DRAM initialization for non-debugger specific applications (like when porting to bootloaders). This tool may be updated on an as-needed basis for bug fixes or future improvements.  There is no schedule for aforementioned maintenance. For questions or additional assistance using this tool, please contact your local sales or FAE.

Enable HDMI CEC function Board: i.MX8MQ Board BSP version: imx-android-11.0.0_2.2.0  Following the Android user guide download and built the Android-11.0.0_2.2.0 BSP  The build directory shared here:  http://10.168.2.226/android/build_folder/device/nxp/imx8m/evk_8mq/hdmicec/. or use the files in attachment. The steps are: Copy the above link code to their android env under device/nxp/imx8m/evk_8mq/hdmicec/.  In device/nxp/imx8m/evk_8mq/evk_8mq.mk, adding below code: +PRODUCT_PACKAGES += \ hdmi_cec.nxp\ hdmicec_test" (2) Compile that. (3) Copy to board  adb root adb remount adb push hdmi_cec.nxp.so /vendor/lib64 adb push hdmi_test /vendor/bin evk_8mq:/vendor/bin # ./hdmicec_test [  349.297183] msg[0]=0x40 [  349.299641] msg[1]=0x4

Some customers want a method to build imx8mp isp standalone instead of using yocto. For such purpose, the NXP kernel, yocto imx-isp and yocto vvcam can be built separately on your local machine. After necessary files are remotely transferred, you will be able to run isp on an evk board. The attached file contains detailed steps for building isp standalone. Please see the guide for further information.

  From L5.4 BSP, the iMX8QM HDMI RX feature is removed from BSP, but it is added back in L5.10.52 2.1.0 BSP. The followed is the detail steps to use HDMI RX.   We need enable the followed kernel config to make hdmirx driver work:     CONFIG_IMX8_MEDIA_DEVICE=y     CONFIG_MHDP_HDMIRX=y apply the attached kernel patch. put hdmi firmware “hdmirxfw.bin” and “hdmitxfw.bin” to SD card’s FAT partition test command:     gst-launch-1.0 v4l2src device=/dev/video2 ! autovideosink   Note: To test the hdmi feature, the display should also use the HDMI TX. And in Uboot, to load the hdmirx firmware, we can run the followed commands first, then run the "boot" command:     run loadhdprx     hdprx load 0x9c800000     setenv fdt_file imx8qm-mek-hdmi-rx.dtb  

Here are some debug methods for kernel performance requirements or related issues. It includes all the common methods such as oops/panic issues, memory issues, and so on. Please check it in the attachments for details. OS and System analysis Oops/Panic case addr2line objdump gdb Pstore Kdump Memory debugging SLAB KASAN Kmemleak Performance Perf Ftrace eBPF/bcc

Symptoms   When configure a gpio pin for a driver in the dts/dtsi file like below example,   e.g.   a-switch {            compatible = "a-switch-driver";            pinctrl-names = "default";            pinctrl-0 = <&pinctrl_switch>;            gpios = <&lsio_gpio1 1 GPIO_ACTIVE_HIGH>;            status = "okay"; };   pinctrl_switch: switch_gpio {     fsl,pins = < IMX8QXP_SPI2_SDO_LSIO_GPIO1_IO01    0x21 >; };   then you may get the error when request the gpio in the driver during the kernel boot up.   Error message like this: a-switch: failed to request gpio a-switch: probe of a-switch failed with error -22   Linux version: L5.4.x   Diagnosis   Because the gpio_mxc_init function run before the function imx_scu_driver_init. The pm_domains for gpio is not ready before running mxc_gpio_probe, so gpio request will be failed.     Solution   There are two ways to resolve this issue 1. Build the driver as a module. i.e. select the driver in kernel’s menuconfig as “M”. Then , run “insmod” to load the driver after the kernel boot up.   OR   2. Apply below patch, let gpio driver init after scu driver. diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index 1dfe513f8fcf..52b5799040b3 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -892,7 +892,7 @@ static int __init gpio_mxc_init(void) return platform_driver_register(&mxc_gpio_driver); } -subsys_initcall(gpio_mxc_init); +device_initcall(gpio_mxc_init);  

adv7180 is the 8 bits parallel CSI interface TVin to iMX8QXP validation board. Its weaving mode de-interlace can be supported on both iMX8QXP B0 and C0 chips, but blending mode de-interlace can only work on iMX8QXP C0 chips.   ISL79987 is the 4 virtual channel TVin chip which can input 4 CVBS cameras to iMX8QXP with MIPI CSI2 inteface, it can only work with iMX8QXP C0 chips. The iMX8QXP B0 chips have MIPI CSI2 virtual channel errata.   To test the capture to file: $ /unit_tests/V4L2/mx8_v4l2_cap_drm.out -cam 1 -num 300 -fmt YUYV -of   To test the preview on screen: $ killall weston $ /unit_tests/V4L2/mx8_v4l2_cap_drm.out -cam 1 -fmt RGBP -num 30000   Note: 1. For weaving mode de-interlace, when the ISI is doing de-interlace, it can't do CSC at the same time, so preview will get color issue, because the real output video is always YUYV format. 2. For blending mode de-interlace, it must use ISI0, so for ISL79987, only one camera can use blending mode, the other three cameras are still using weaving mode. The preview color is OK for such use case. 3. The patch is for L4.19.35 BSP.     2019-11-14 update: Add the test application "mx8_v4l2_cap_drm.tar.gz" to support YUYV render to display. Test command to render 4 weaving mode cameras:    ./mx8_v4l2_cap_drm.out -cam 0xF -fmt YUYV -num 30000     2020-04-29 update: Add "0006-isl7998x-fix-the-mipi_bps-overwrite-issue-from-set_f.patch", it fixed the issue that MIPI bps information in isl7998x_data->format.reserved[0] had been overwritten by isl7998x_set_fmt().   2021-06-11 update: Added the patches based on L5.4.70_2.3.0 GA BSP.

The i.MX 8QuadXPlus Multisensory Enablement Kit (MEK) is a NXP development platform based on Cortex A-35 + Cortex-M4 cores. Built with high-level integration to support graphics, video, image processing, audio, and voice functions, the i.MX 8X processor family is ideal for safety-certifiable and efficient performance requirements. This tutorial shows how to enable the Cortex-M4 using the MCUXpresso SDK package and loading the binary from the network. NOTE: It is also possible to load the Cortex-M4 image from the SCFW using the imx-mkimage utility. But now we are going to focus on MCUXpresso. Setting up the machine   Install cmake on the host machine: $ sudo apt-get install cmake Download the armgcc toolchain and export the location as ARMGCC_DIR: $ export ARMGCC_DIR=<your_path_to_arm_gcc>/gcc-arm-none-eabi-9-2020q2/ NOTE: The ARMGCC_DIR variable needs to be exported on the terminal used for compilation. To setup the TFTP server on the host machine: Configuring your Host PC for TFTPPermalink   The first step is to install all the prerequisite packages for TFTP: $ sudo apt-get install xinetd tftpd tftp Create a TFTP folder in your desired location with root owner and the “rwx” permission for all users: $ sudo mkdir /tftpboot $ sudo chmod –R 777 /tftpboot $ sudo chown –R root /tftpboot Create a configuration file for the TFTP with the following content. (The server_args parameter must match with the folder created above) $ cat /etc/xinetd.d/tftp service tftp { protocol = udp port = 69 socket_type = dgram wait = yes user = root server = /usr/sbin/in.tftpd server_args = -s /tftpboot disable = no } Restart the xinetd service: $ sudo /etc/init.d/xinetd restart You can place any file at the TFTP folder and load it through U-Boot, you can also create symbolic links from your building directory avoiding to copy and paste your zImage and dtb files every time. Configuring your Host PC for NFSPermalink   Install all the needed packages for NFS: $ sudo apt-get install nfs-kernel-server Create a folder for placing your rootfs: $ mkdir /tftpboot/rfs Add the following line in the end of your /etc/exports file: /tftpboot/rfs *(rw,no_root_squash,no_subtree_check) Restart the NFS service: $ sudo service nfs-kernel-server restart Place your rootfs or create a symbolic link for the NFS folder.    Downloading the SDK Download the MCUXpresso following these steps: Click on “Select Development Board”; Select MEK-MIMX8QX under “Select a Device, Board, or Kit” and click on “Build MCUXpresso SDK” on the right; Select “Host OS” as Linux and “Toolchain/IDE” as GCC ARM Embedded; Add “FreeRTOS” and all the wanted Middleware and hit “Request Build”; Wait for the SDK to build and download the package. Building the image All demos and code examples available on the SDK package are located in the directory <<SDK_dir>>/boards/mekmimx8qx/. This tutorial shows how to build and flash the hello_world demo but similar procedures can be applied for any example (demo, driver, multicore, etc) on the SDK. To build the demo, enter the armgcc folder under the demo directory and make sure that the ARMGCC_DIR variable is set correctly. $ cd ~/SDK_2.3.0_MEK-MIMX8QX/boards/mekmimx8qx/demo_apps/hello_world/armgcc $ export ARMGCC_DIR=<your_path_to_arm_gcc>/gcc-arm-none-eabi-9-2020q2/ Run the build_release.sh script to build the code. $ ./build_release.sh NOTE: If needed, give the script execution permission by running chmod +x build_release.sh. This generates the M4 binary (hello_world.bin) under the release folder. Copy this image to the /tftpboot/ directory on the host PC. NOTE: This procedure shows how to build the M4 image that runs on TCM. To run the image from DDR, use the build_ddr_release.sh script to build the binary under the ddr_release folder. Flashing the image Open two serial consoles, one for /dev/ttyUSB0 for Cortex-A35 to boot Linux, and one for /dev/ttyUSB1 for Cortex-M4 to boot the SDK image. On the A35 console, with a SD Card with U-Boot, stop the booting process and enter the following commands to load the M4 binary to TCM: => dhcp => setenv serverip <ip_from_host_pc> => tftp 0x88000000 hello_world.bin => dcache flush => bootaux 0x88000000 Then the M4 core will load the image to the /dev/ttyUSB1 console.    

SW Environment Setup: 1. Prepare L5.10.35 Yocto and build Image  The prebuilt image also is available and useable. 2. Flash image to the SD card  Refer to the Yocto User Guide. 3. Compile flash.bin without M4 and flash it to sdcard (flash.bin as attachment)  make SOC=iMX8QM flash sudo dd if=flash.bin of=/dev/sde bs=1k seek=32 conv=fsync HW Environment Setup: Prepare the imx8qm MEK CPU board and base board and DB9 male cable, connect to CAN0 and CAN1 female connector on base board. (Pin to Pin connection) User Case: 1. Power on board and configure specify dtb file in uboot  setenv fdt_file imx8qm_mek.dtb 2. Boot up and config bitrate for can0 and can1 in kernel root@imx8qmmek:~# ip link set can0 up type can bitrate 500000 root@imx8qmmek:~# ip link set can1 up type can bitrate 500000 3. Check CAN0 and CAN1 devices root@imx8qmmek:~# ifconfig can0: flags=193<UP,RUNNING,NOARP> mtu 16 unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 10 (UNSPEC) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 device interrupt 85 can1: flags=193<UP,RUNNING,NOARP> mtu 16 unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 10 (UNSPEC) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 device interrupt 86 3. Run candump for CAN1 root@imx8qmmek:~# candump can1 & [1] 1215 [ 65.624580] can: controller area network core [ 65.630225] NET: Registered protocol family 29 [ 65.641158] can: raw protocol 4. Run cansend for CAN0 root@imx8qmmek:~# cansend can0 5A1#11.2233.44556677.88 can1 5A1 [8] 11 22 33 44 55 66 77 88   The above red is output result from CAN1.

Use case: iMX8QXP system can be a video input source to another system.   Hardware Pins： LCDIF_D00 ~ LCDIF_D07 LCDIF_CLK LCDIF_VSYNC LCDIF_HSYNC LCDIF_EN   Reference patch： It is based on L5.4.70_2.3.0 GA BSP.  File: L5.4.70_2.3.0-iMX8QXP-LCDIF-add-YUV422-8-bits-output.patch Customer can change the timing parameters in file "panel-lcdif-yuv422.c" as needed, the default timing is a 1280x720 P30 mode: static const struct display_timing yuv422_lcd_timing = {     .pixelclock = { 74250000, 74250000, 74250000 },     .hactive = { 1280, 1280, 1280 },     .hfront_porch = { 220, 220, 220 },     .hback_porch = { 110, 110, 110 },     .hsync_len = { 40, 40, 40 },     .vactive = { 720, 720, 720 },     .vfront_porch = { 20, 20, 20 },     .vback_porch = { 5, 5, 5 },     .vsync_len = { 5, 5, 5 },     .flags = DISPLAY_FLAGS_DE_HIGH, };   Test application: drm_test_yuv.zip: it can set framebuffer to UYVY mode, in this case, no CSC is needed, the data in framebuffer memory will be same as output on display data interface. drm_test_rgb.zip: it can set framebuffer to RGBA mode, in this case, RGB to YUV CSC is needed, application can draw RGB data into framebuffer as normal, the LCDIF will convert it to YUV422 format on the fly, then output the YUV data to display interface.    

This article will describe one suggestion for one issue that UART continuously generate RX interrupts and receive 0xFF even when Rx line is continuously high in some cases on imx6 series. Below I will explain with imx6DL. Some settings are just to make it easier to reproduce. BSP version: L5.4.70-2.3.0 Board HW: MCIMX6DL-SDB When issue happen Config imx6DL UART3 as the serial port to 1200 baud, 8-N-1 format. Keep the RX Line high. Make the RX line low and keep it for a short time (360 usec-370 usec).   At this condition, you will find that the UART will continuously generate RX interrupts and show receiving 0xFF even you make the RX line return to be high. Why issue happen The low time is not in the correct range and out of our spec. In the imx6DL AEC document, there is one chapter named UART Receiver like blow   If using 1200 band, that means one valid bit time is 833 usec. And there is a definition that “tolerate 1/(16 x Fbaud_rate) tolerance in each bit”. That’s means in the case of 1200 baud. A range of valid bit is 781 to 885 usec. But is reproducing, the Low level time is 360 usec. This time out of range will make UART state machine to be confused. How to fix Actually, the best way is following our spec. If there is such an unknown situation in the customer’s environment, then the following method could be regarded as a suggestion to fix the issue meet by the customer. The interrupt handler will check USR1[AWAKE]. 2    If AWAKE is asserted, clear it and proceed as usual (assume we have valid data), else, check if USR1[AGTIM] is asserted. 3    if AGTIM is asserted, clear it and proceed as usual, else perform software reset (assume we have invalid data). Checking AGTIM is for one race condition when the RX fifo has some characters (less than RXTL) but no more data is coming in. When following this procedure, the UART will perform a software reset when a block interrupt occurs. Notes: From customer report, error could be cleared if a valid start-bit is detected on the RX line. This needs to be verified by the customer themselves. Test code has been included in attachment.   Besst Regards

The A53 Debug Console Changing consists in several major updates like: RDC settings, Pinmux, Clocks and Ecosystem Updates.

Some case need configure the GPIO as power off button. One solution is to use “gpio-keys” to send the “KEY_POWER” event to the system. Co-work with systemd, system gets power off.