Sometimes we need to use an SPI bus to communicate with sensors or another device. Unfortunately, by default on iMX8MN-EVK, we have the ECSPI2 disabled on our BSP.   We can use that peripheral on Linux enabling it in the device tree.   To enable the ECSPI2 on the device tree we have to add the next on imx8mn-evk.dtsi:     status = "okay"; }; +&ecspi2 { + #address-cells = <1>; + #size-cells = <0>; + fsl,spi-num-chipselects = <1>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_ecspi2 &pinctrl_ecspi2_cs>; + cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>; + status = "okay"; + + spidev0: spi@0 { + reg = <0>; + compatible = "rohm,dh2228fv"; + spi-max-frequency = <500000>; + }; +}; + &fec1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_fec1>;   On iomux node:   + pinctrl_ecspi2: ecspi2grp { + fsl,pins = < + MX8MN_IOMUXC_ECSPI2_SCLK_ECSPI2_SCLK 0x82 + MX8MN_IOMUXC_ECSPI2_MOSI_ECSPI2_MOSI 0x82 + MX8MN_IOMUXC_ECSPI2_MISO_ECSPI2_MISO 0x82 + >; + }; + + pinctrl_ecspi2_cs: ecspi2cs { + fsl,pins = < + MX8MN_IOMUXC_ECSPI2_SS0_GPIO5_IO13 0x40000 + >; + }; + pinctrl_ir_recv: ir-recv { fsl,pins = < MX8MN_IOMUXC_GPIO1_IO13_GPIO1_IO13 0x4f    after modifying and compiling the device tree you can see the device active like this:     Connection:   Test: spidev_test -D /dev/spidev1.0 -v       You can use the devsheell of yocto to make the changes:   https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/How-to-use-Devshell-to-compile-device-tree-files/ta-p/1727428

this is tested with MX93(A1) EVK running 6.1.55_2.2.0 pre-build image.   USB can output test patterns with either one of the setup below: 1. through device node: root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# cat role gadget root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# echo host > role [ 2672.864083] ci_hdrc ci_hdrc.0: EHCI Host Controller [ 2672.868996] ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 1 [ 2672.893320] ci_hdrc ci_hdrc.0: USB 2.0 started, EHCI 1.00 [ 2672.899314] hub 1-0:1.0: USB hub found [ 2672.909235] hub 1-0:1.0: 1 port detected root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# cat role host root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# echo 4 > port_test root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# echo 3 > port_test root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# echo 2 > port_test root@imx93evk:/sys/kernel/debug/usb/ci_hdrc.0# echo 1 > port_test   2. use memtool to program registers for i in $(find /sys -name control | grep usb);do echo on > $i;echo "echo on > $i";done; echo host > /sys/kernel/debug/usb/ci_hdrc.0/role #Offset:184h USB_OTG1 base address: 4C10_0000h base address USB_OTG2 base address: 4C20_0000h Register address Register address：base address+offset $ /unit_tests/memtool 0x4c100184 1 # Force to output Test Packet for Eye Diagram Test $ /unit_tests/memtool 0x4c100184=0x18041215 #Force to output J_STATE $ /unit_tests/memtool 0x4c100184=0x18011215 #Force to output K_STATE $ /unit_tests/memtool 0x4c100184=0x18021215 #Force to output SE0 (host) / NAK (device) $ /unit_tests/memtool 0x4c100184=0x18031215

Hey everyone !! This piece covers how to configure the iMX93EVK board to wake up Cortex A55[ running Linux] from Cortex M33 core[running a bare metal application].    We will be using UART console on Cortex M33 to signal Cortex A55 via RPMSG to wake-up from deep sleep.   This can be done as follows:-   1. Boot iMX93EVK with RPMSG enabled DTB and load M33 binary via UBOOT   After booting to Uboot terminal, set the fdtfile variable to <rpmsg dtb> that will help us enable rpmsg in the kernel.   u-boot=> setenv fdtfile imx93-11x11-evk-rpmsg.dtb u-boot=> setenv bootargs ${jh_clk} ${mcore_clk} console=${console} root=${mmcroot}   then, load the M33 binary from the eMMC partition    u-boot=> fatload mmc 0:1 0x80000000 imx93-11x11-evk_m33_TCM_power_mode_switch.bin 18996 bytes read in 14 ms (1.3 MiB/s)   u-boot=> cp.b 0x80000000 0x201e0000 0x4a34 u-boot=> saveenv Note:-  Do not run the M33 core via bootaux at this point, instead just boot to Linux   u-boot=> boot         2. Starting the Cortex M33 core from Cortex A55[running Linux]   Once linux is up, load the elf of Cortex M33 power mode switch application.   echo ~/power_mode_switch.elf > /sys/devices/platform/imx93-cm33/remoteproc/remoteproc0/firmware   start the M33 core   echo start > /sys/devices/platform/imx93-cm33/remoteproc/remoteproc0/state   On console of Cortex M33 you will see the output as below:-   The log below shows the output of the power mode switch demo in the terminal window: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Start SRTM communication Task 1 is working now #################### Power Mode Switch Task #################### Build Time: Nov 10 2023--15:15:16 Core Clock: 200000000Hz Select the desired operation Press A to enter: Normal RUN mode Press B to enter: WAIT mode Press C to enter: STOP mode Press D to enter: SUSPEND mode Press W to wakeup A55 core Press M for switch M33 Root Clock frequency between OD/ND. Waiting for power mode select.. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~   M33 at this point is ready to wake up the A55 core.     3. Put A55 core to deep sleep and trigger a wakeup from M33 console   To put A55 to deep sleep   echo mem > /sys/power/state you will see something like below on linux console:-     At this point, A55 core is in deep sleep power saving mode. So the A55 console will not respond to any of the key presses. Go on, give it a try 🙂   Now to wake up this core, go to M33 serial console and type 'W'  This will wake up A55 core and you will see the logs denoting that the core has woken up:-   That's it! that's how you exercise UART wake-up functionality on imx93evk. Please feel free to drop any follow-up questions or additional thoughts on this.

This article introduces the overall functionality of i.MX8X security. Simulate the process of i.MX8X signature through OpenSSL provides readers with a deeper understanding of this process.   Because lots of limitation for attachments. Have to do following.  1. download                       T4549-i.MX8X security overview and AHAB deep dive.zip.001.zip                      T4549-i.MX8X security overview and AHAB deep dive.zip.002.zip                      T4549-i.MX8X security overview and AHAB deep dive.zip.003.zip 2. decompress                T4549-i.MX8X security overview and AHAB deep dive.zip.001.zip                T4549-i.MX8X security overview and AHAB deep dive.zip.002.zip                T4549-i.MX8X security overview and AHAB deep dive.zip.003.zip 3. Put together and decompress         T4549-i.MX8X security overview and AHAB deep dive.zip.001    T4549-i.MX8X security overview and AHAB deep dive.zip.002    T4549-i.MX8X security overview and AHAB deep dive.zip.003  

  Environment i.MX8MP EVK, SDK2.15   The default rpmsg buffer size in SDK is 512Bytes(16 Bytes header + 496Bytes payload). This knowledge base will try to change the default buffer size in rpmsg framework. Steps:   1.Modify rpmsg payload size in SDK PATH: SDK\evkmimx8mp_rpmsg_lite_str_echo_rtos_imxcm7\rpmsg_config.h     //! RL_BUFFER_PAYLOAD_SIZE //! //! Size of the buffer payload, it must be equal to (240, 496, 1008, ...) //! [2^n - 16]. Ensure the same value is defined on both sides of rpmsg //! communication. The default value is 496U. #define RL_BUFFER_PAYLOAD_SIZE (1008)     2. Modify buffer size in rpmsg linux framework and buffer pool in dts. PATH: drivers/rpmsg/virtio_rpmsg_bus.c            arch/arm64/boot/dts/freescale/imx8mp-evk-rpmsg.dts   Test steps:   Modify the send buffer in imx_rpmsg_tty.c     #define MSG "hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world! hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world! hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!"       Modify buffer limitation in SDK PATH: evkmimx8mp_rpmsg_lite_str_echo_rtos_imxcm7\main_remote.c     /* Globals */ static char app_buf[1024]; /* Each RPMSG buffer can carry less than 512 payload */       Terminal output We can see that the MAX buffer size received in SDK is not limited to 512Bytes     Nameservice sent, ready for incoming messages... Get Message From Master Side : "hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world! hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world! hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!hello world!" [len : 674]       If we use a larger buffer like 2022 Bytes, we will see error when driver load.     [ 2673.447384] imx_rpmsg_tty virtio0.rpmsg-virtual-tty-channel-1.-1.30: message is too big (2022) [ 2673.456271] imx_rpmsg_tty virtio0.rpmsg-virtual-tty-channel-1.-1.30: rpmsg_send failed: -90 [ 2673.465556] imx_rpmsg_tty virtio0.rpmsg-virtual-tty-channel-1.-1.30: rpmsg_dev_probe: failed: -90 [ 2673.474496] imx_rpmsg_tty: probe of virtio0.rpmsg-virtual-tty-channel-1.-1.30 failed with error -90          

We are pleased to announce that Config Tools for i.MX v15.0 are now available. Downloads & links To download the installer for all platforms, please login to our download site via:  https://www.nxp.com/design/designs/config-tools-for-i-mx-applications-processors:CONFIG-TOOLS-IMX Please refer to  Documentation  for installation and quick start guides. For further information about DDR config and validation, please go to this  blog post. Release Notes Full details on the release (features, known issues...)Version 15.0 • The product is based on Eclipse 2023-06 TEE – Setting a security level for a special three-state model is improved. Pins – Validation to ensure that elements can be configured by the selected core is added. – Rows are sorted in the Peripheral Signals routing dialog. – A connected pins column in External User Signals always shows the pin's full name. – The missing scroll bar in the External User Signals view is fixed. Clocks – Support for multicore code generation is added. – Global configuration elements now support a tree structure and can be categorized. – Fractional PLL now supports a custom range and negative numerator. – Scrolling in the clock diagram by pressing the mouse wheel (drag and drop) is supported. DCD – The issue with the code generation that stopped working after the drag and drop of a group is fixed.  

some customers doesn't have any issue on old bsp, but have bring up issue on new 6.1 bsp, this article is about this and how to fix this

Symptoms   On i.MX8MP, when inputting a 80% duty, 0.4V-1.8V, 3KHz square wave, we observed that the system may hang. We also tested i.MX8MN and i.MX8MM and observed the same phenomenon. In i.MX8MN RM, there's a note in GPC chapter:     We believe that the issue described in this note exists not only in the iMX8MN, but also in the iMX8MP and iMX8MM. Meanwhile, there is not only a problem with power down in this issue, but also a problem with wait mode. Diagnosis   In debugging, we find that avoiding accessing LPCR_A53_AD register in imx_set_cluster_powerdown can fix the issue. So we think that due to frequently power up/down of cores, cores have chances failed to power up. When the IRQ behavior become more complex, because the IRQ is an async event, it will come in any time. if the wait mode is enabled, in some conner case, the GPC internal LPM mode state machine will run into problem, then lead to system failure. Solution   1. A workaround patch that bypass the wait mode setting during the cpuidle.. See the patch attached. 2. Will add the Note about "SCU power down should not be enabled in wait mode" to i.MX8MP and i.MX8MM RM. 3. Will try to identify this issue into errta document, ticket TKT0632147.

Hardware i.MX 93 EVK​ TFT LCD 480x272 RGB888 (NV3047E, parallel)​ Condition A55 off​ DDR self-refresh​ OCRAM for framebuffer, TCM for code/data​ LCDIF on with parallel interface​ M33 update panel content each second​ 255KB single frame buffer(RGB565) (fit in OCRAM: 0x20480000 ~ 0x204DFFFF)​ Code Bitbucket：ssh://[email protected]/mpucnse/imx93-cm33-usecase.git​ Branch: imx93_sdk_2.14.1-lcd_on_ocram​ Demo code: imx93-cm33-usecase/boards/mcimx93evk/demo_apps/lcd_on_ocram​ DTS: imx93-cm33-usecase/boards/mcimx93evk/demo_apps/lcd_on_ocram/dts​ Working Flow   ​Test Flow In uboot console,​ setenv mmcargs $mmcargs clk-imx93.mcore_booted​ setenv fdtfile imx93-11x11-evk-lcd_panel.dtb​ fatload mmc 1:1 0x80000000 sdk20-app.bin;cp.b 0x80000000 0x201e0000 0x10000;bootaux 0x1ffe0000 0​ boot​ In kernel console,​ echo mem > /sys/power/state​ start the power test Power Consumption SoC power: 94.4mW​ [email protected]​ CM33@100MHz​ CM33@100MHz​ A55 suspend​ DDR retention​ WAKEUPMIX off​ NICMIX and MEDIAMIX on​  ​  

This is a simple document for recording some known-how and tips for building up the Windows 10 IoT development environment for i.MX platform. It can only be used as a complement for official document in BSP package (Guide/Release Note/etc.). Applicable for: Windows 10 IoT, i.MX BSP v1.4.1 (date to Nov/2023) Please refer to the PDF attached.

BSP: L6.1.36 Some customer need use adb under usb ffs. The adb in Yocto can greatly improves development efficiency. This is a demo for enabling adb on Yocto.   Yocto local.conf IMAGE_INSTALL:append = "android-tools android-tools-adbd" PREFERRED_PROVIDER_android-tools-conf = "android-tools-conf-configfs"   Test script for launching adbd modprobe g_ffs idVendor=0x1fc9 idProduct=0x0146 iSerialNumber="ZhimingLiu" mkdir -p /dev/usb-ffs/adb mount -t functionfs adb /dev/usb-ffs/adb -o uid=2000,gid=2000 adbd &   Test on Windows: PS C:\Users\Administrator\Desktop\platform-tools> .\adb.exe devices List of devices attached ZhimingLiu device PS C:\Users\Administrator\Desktop\platform-tools> .\adb.exe shell sh-5.2# uname -a Linux imx8mp-lpddr4-evk 6.1.36+g04b05c5527e9 #1 SMP PREEMPT Fri Nov 24 04:46:22 UTC 2023 aarch64 GNU/Linux sh-5.2# ls config ffs t.sh test2.sh sh-5.2# cd / sh-5.2# ls bin dev home lost+found mnt proc run srv tmp usr boot etc lib media opt root sbin sys unit_tests var sh-5.2#

Usually, device tree source files are not a signal pure dts file. It could include dtsi, dts or C code heads .h files. Need C compiler finish the pre-compile to a pure dts file first. It is integrated inside the like Linux build system(Makefile, etc.). This document shows the original way to compile device tree. This document will show compile device tree under windows.    

Board : i.MX93 EVK BSP: imx L6.1.1-1.0.0 Gui guider: 1.6.1   We have a GUI software tool called GUI Guider. It is a user-friendly graphical user interface development tool from NXP that enables the rapid development of high quality displays with the open-source LVGL graphics library. The GUI demo can run on the i.MX93EVK board. (https://www.nxp.com/design/software/development-software/gui-guider:GUI-GUIDER)   This document will show you an example how the buttons(gpio) on the EVK to interacting with the GUI. Basically, customer could use the same method to use the gpio pins to control everything.   On the i.MX93 EVK board, there are two buttons BTN1 and BTN2. They are connected to GPIO IO23 and GPIO IO24. Below is the schematic.    Buttons on the board.      SW1005 on the board   In the EVK's device tree file, need to change the pinmux for the two buttons like this: pinctrl_spdif: spdifgrp { fsl,pins = < // MX93_PAD_GPIO_IO22__SPDIF_IN 0x31e // MX93_PAD_GPIO_IO23__SPDIF_OUT 0x31e MX93_PAD_GPIO_IO23__GPIO2_IO23 0x31e MX93_PAD_GPIO_IO24__GPIO2_IO24 0x31e >; note: all the pins are defined in imx93-pinfunc.h.   For getting the input value of the buttons in user's space, I use the sysfs gpio. Build the imx-image-multimedia image first and then select the GPIO_SYSFS in kernel's menuconfig.   $ DISTRO=fsl-imx-xwayland MACHINE=imx93evk source imx-setup-release.sh -b build-xwayland $ bitbake imx-image-multimedia   After the build completed, go to the kernel's menuconfig to select the GPIO sysfs. $ bitbake linux-imx -c menuconfig [*] General setup-> Configure standard kernel features (expert users) [*] Device Drivers->GPIO Support-> /sys/class/gpio/... (sysfs interface)   Build the whole image again by "$ bitbake imx-image-multimedia".   Using the UUU to program the image to the EMMC on the EVK board. uuu -b emmc_all imx-image-multimedia-imx93evk.rootfs.wic.zst   Connect the LVDS to the board. Use the corresponding dtb to boot the board. In u-boot, set the dtb file. => setenv fdtfile imx93-11x11-evk-boe-wxga-lvds-panel.dtb => saveenv   Then restart the board. After the board boot up, it will look like below.     You need to calibrate the LVDS touch screen before it can normally use. Please use this command: $ weston-touch-calibrator LVDS-1     Now, build the GUI guider example. I use the Air Conditioner example. Download the GUI guider from the gui-guider web page: https://www.nxp.com/design/software/development-software/gui-guider:GUI-GUIDER   Follow the steps from the below web page to build the i.MX BSP and the gui example code. https://docs.nxp.com/bundle/GUIGUIDERUG-1.6.1/page/topics/yocto.html   After the gui-guider build completed, use the 'scp' command to transfer the gui_guider executable file to the board. Execute the command on your host PC like this: $ scp bld-imx93evk/tmp/work/armv8a-poky-linux/gui-guider/1.6.0-r0/image/usr/bin/gui_guider root@<Your Board IP address>:/ Note: You could use a router to connect your board and your host PC. They are on the same network so could use the 'scp' command to transfer the file to your board.   On your board, type the following commands to execute the gui. $ chmod 755 gui_guider $ ./gui_guider &   Then the GUI is running like this:   Now, let me explain how to find out the gpio number. Type the following command to show the mapping addresses of gpio. root@imx93evk:/# cat /sys/kernel/debug/gpio gpiochip3: GPIOs 0-31, parent: platform/47400080.gpio, 47400080.gpio: gpiochip0: GPIOs 32-63, parent: platform/43810080.gpio, 43810080.gpio: gpiochip1: GPIOs 64-95, parent: platform/43820080.gpio, 43820080.gpio: gpio-64 ( |cd ) in hi IRQ ACTIVE LOW gpio-71 ( |regulator-usdhc2 ) out lo gpiochip2: GPIOs 96-127, parent: platform/43830080.gpio, 43830080.gpio: gpiochip6: GPIOs 472-477, parent: i2c/0-001a, wm8962, can sleep: gpiochip5: GPIOs 478-487, parent: platform/adp5585-gpio.1.auto, adp5585-gpio, can sleep: gpio-479 ( |regulator-audio-pwr ) out hi gpio-483 ( |regulator-can2-stby ) out hi ACTIVE LOW gpio-486 ( |enable ) out hi gpiochip4: GPIOs 488-511, parent: i2c/1-0022, 1-0022, can sleep: gpio-492 ( |Headphone detection ) in lo IRQ gpio-501 ( |? ) out hi gpio-502 ( |regulator-vdd-12v ) out hi gpio-505 ( |reset ) out lo gpio-507 ( |? ) out hi gpio-508 ( |reset ) out lo ACTIVE LOW   The gpio pins of two buttons are GPIO2_IO23 and GPIO2_IO24. They are belongs to gpio2. In the imx93.dtsi, the gpio2's address is "gpio2: gpio@43810080". So, base on the information output from "/sys/kernel/debug/gpio", the gpio2 is mapping to "gpiochip0: GPIOs 32-63". So, the GPIO2_IO23 is 32+23=55, and the GPIO2_IO24 is 32+24=56.   To verify the gpio number is correct or not. We could do the following test. root@imx93evk:/# echo 55 > /sys/class/gpio/export root@imx93evk:/# echo in > /sys/class/gpio/gpio55/direction root@imx93evk:/# echo 56 > /sys/class/gpio/export root@imx93evk:/# echo in > /sys/class/gpio/gpio56/direction   Then, run these two commands to check the values. root@imx93evk:/# cat /sys/class/gpio/gpio55/value root@imx93evk:/# cat /sys/class/gpio/gpio55/value   When the button is not pressed, the value is 1. When press the button, the value is 0.  We could add the same in the GUI's custom.c. Open the GUI Guider software and add the code in the custom.c. /********************* * INCLUDES *********************/ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <fcntl.h> #include "lvgl.h" #include "custom.h" #include "ui_Aircon.h" #include "guider_customer_fonts.h" /********************** * STATIC VARIABLES **********************/ int fdbtn1,fdbtn2,fdgpio; int btn1_pressed; int btn2_pressed; char btn1_value, btn2_value; void custom_func(void) { fdbtn1 = open("/sys/class/gpio/gpio55/value", O_RDWR); fdbtn2 = open("/sys/class/gpio/gpio56/value", O_RDWR); read(fdbtn1, &btn1_value, 1); read(fdbtn2, &btn2_value, 1); if(btn1_value=='0' && btn1_pressed) { btn1_pressed=0; ui_aircon_update_temp(0, kAIRCON_TempUp); } if(btn1_value=='1') btn1_pressed=1; if(btn2_value=='0' && btn2_pressed) { btn2_pressed=0; ui_aircon_update_temp(0, kAIRCON_TempDown); } if(btn2_value=='1') btn2_pressed=1; close(fdbtn1); close(fdbtn2); } void custom_init(lv_ui *ui) { fdbtn1 = open("/sys/class/gpio/gpio55/value", O_WRONLY); if (fdbtn1 == -1) { fdgpio = open("/sys/class/gpio/export", O_WRONLY); write(fdgpio,"55",3); write(fdgpio,"56",3); close(fdgpio); fdgpio = open("/sys/class/gpio/gpio55/direction", O_WRONLY); write(fdgpio,"in",3); close(fdgpio); fdgpio = open("/sys/class/gpio/gpio56/direction", O_WRONLY); write(fdgpio,"in",3); close(fdgpio); } else close(fdbtn1); ... ... ... ...   Add the custom_func() in the custom.h. #ifndef __CUSTOM_H_ #define __CUSTOM_H_ #ifdef __cplusplus extern "C" { #endif #include "gui_guider.h" void custom_init(lv_ui *ui); + void custom_func(void);   Also, need to add the custom function() into the dead loop in main.c.   To modify the code, bld-imx93evk$ vim tmp/work/armv8a-poky-linux/gui-guider/1.6.0-r0/gui-guider-1.6.0/ports/linux/main.c   while(1) { + custom_func(); // <--- Add the custom function here. /* Periodically call the lv_task handler. * It could be done in a timer interrupt or an OS task too.*/ time_till_next = lv_wayland_timer_handler(); #if LV_USE_VIDEO video_play(&guider_ui); #endif /* Run until the last window closes */ if (!lv_wayland_window_is_open(NULL)) { break; }   Re-build the code after modified. bld-imx93evk$ bitbake gui-guider -c compile -f   Build the whole image again. bld-imx93evk$ bitbake gui-guider Then use the 'scp' command to transfer the new gui-guider file to the board.   Finally, you can use the buttons on the EVK board to set the temperature up and down.                          

Symptoms   Trying to initialize a repo, for example:  $repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-mickledore -m imx-6.1.36-2.1.0.xml we have the below log: File "/home/username/bin/repo", line 51 def print(self, *args, **kwargs): ^ SyntaxError: invalid syntax   Workaround (1)   The first workaround consist in change the python alternatives (caused when you have installed two or more python versions). NOTE: in my case, the python version that i want to change as first priority is python3.8 $sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.8 1   Then we run: $sudo update-alternatives --config python    To verify if your python priority was changed successfully try: $python --version   You should see the version configured as priority number 1.     Workaround (2)   The workaround is very simple, only we need modify the repo file $ nano ~/bin/repo   and we will change the python interpreter in the first line (from python to python3): ORIGINAL FILE   EDITED FILE   After to do this change, repo will works fine again.     I hope this can helps to you!   Best regards.

The configuration of DDR is very important. NXP provides a tool for configuring DDR for users of i.MX series products. Here are the details steps for it. Hope can do help for someone. 1\ The DDR part startup and initialization sequence of MX8MM:   The MX 8M series DDR tools include： DDR Register Programming Aid --->Configurate custom DDR initialization MSCALE DDR Tool（DDR Stress Test Tool） --->Test DDR initialization And DDR interface ---> Generate custom DDR initialization code for the u-boot SPL DDR RPA（RPA） is an Excel spreadsheet tool used to develop DDR initialization for specific DDR configurations (DDR device type, density, etc.) of users. RPA generates DDR initialization (in a separate Excel worksheet tab). Detailed explanations and introductions will be provided here. DDR stress testing tool is a software tool based Windows that initializes PHY and generates DDRC configuration Uboot source code to verify whether DDR initialization can be used for u-boot and OS startup. DDR stress testing script, this format is specifically used for DDR stress detection. First, copy the content from this worksheet tab, and then paste it into a text file, naming the document with the ". ds" file extension. Select this file when performing DDR stress testing. 2\i.MX8M series DDR tool work flow           Above is the DDR Tool flow for the i.MX8MM: DDR RPA Tool: Configure DDR parameters to generate DDR Stress Test script ". ds". DDR Sress Test Tool: Test DDR initialization and DDR interface, generate DDR initialization code for the u-boot SPL DDR driver. For the newest DDR RPA version as below：   https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX8MMini-m845S-DDR-Register-Programming-Aid-RPA/ta-p/1172443 In the above link, you can download the corresponding DDR configuration tools for i.MX8MM using different DDRs.   3\How to use this script to configure DDR parameters (1)Obtain the required DRAM data sheet from the DRAM supplier firstly. The DDR parameter configuration content will be completed in the "Register Configuration" worksheet tab.   (2)"Register Configuration"，Update the device information table to include DRAM information and system usage. DDR RPA tool:  Register Configuration---->Device Information table   It should be filled out based on the datasheet and relevant hardware circuit design of the selected DDR chip. Specific users can refer to the manual for selecting DDR chips and their own hardware design. Take the i.MX 8M Mini LPDDR4 EVK board as example, it selects the Micron MT53D512M32D2DS-053 WT:D, we can go the Micron website to download the DDR’s datasheet and we can see bellow:   Density per channel (Gb)= Device density (Per Channel Per CS)=8Gb Number of ROW Addresses=R[15:0]=16 Number of Channels=2 (2 Channels i.MX8MM DDR is 32bit) Number of COLUMN Addresses=C[9:0]=10 Total DRAM density(Gb) Automatic calculation：Density per channel (Gb) * Number of Channels * Number of Chip Selects used  =8Gb * 2 * 1=16Gb=2GB Bus Width=M32=32bit: i.MX8MM DDR support 32bit Cycle Freq (MHz)=1500MHZ: The DDR controller clock of the i.MX8MM is set to 1500MHZ. The information filled in is shown in the table below:   (3)Browse through various shaded cells in the spreadsheet to update using data from the DRAM table (pay special attention to the "Legend" table to determine the meaning of different shaded cells; in many cases, these cells may not need to be updated). On the parameter filling page, we can also see the following table, with different colors indicating the need to modify and maintain the original parameters and the affected parameter information. On the register configuration tab, basically only the orange part of the color represents the bit segments that usually need to be updated, and the rest do not need to be modified or configured.   (4)Go to the BoardDataBusConfig tab, fill in the i.MX8MM data bus mapping to the memory device correctly. DDR RPA tool: BoardDataBusConfig ---->Configurate data bus bit   Users should pay special attention to ensuring that this worksheet is configured correctly, otherwise the LPDDR4 system may not function properly. The memory controller of i.MX8MM allows for BYTE internal swapping. For layout convenience, BYTE internal swapping is usually performed, so the BoardDataBusConfig column needs to be configured according to the actual schematic design. We can see the tab in the BoardDataBusConfig, user fill the i.MX8MM data bit connection to associated LPDDR4, the filling in of data bits here should be consistent with the order of our hardware design wiring, which means that if there are swapped data bits, the corresponding relationship must be filled in. Take the LPDDR4 connection to the i.MX8MM as example, the highest 8 bits on the channel B of the LPDDR4   connect to the side of DRAM_DQ00~DRAM_DQ07 of CPU, and the lowest 8 bits on the channel B of the LPDDR4 DRAM_DQ08~DRAM_DQ15 of CPU side，the lowest 8 bits on the channel A of the LPDDR4 connect to the DRAM_DQ16~DRAM_DQ23 of CPU side，the highest 8 bits on the channel A of the LPDDR4 connect to the DRAM_DQ24~DRAM_DQ31 of the CPU side. The i.MX8MM memory controller allows for BYTE internal swapping. For layout convenience, BYTE internal swapping is usually performed, and this needs to be filled in according to the actual wiring in the data bus.       (5)Generate the “.ds” file DDR RPA tool: DDR stress test file ----> “.ds”   Copy the content of the DDR stress test file into a text file and name it a. ds file. For subsequent DDR stress testing purposes.   4\Do the DDR Stress test and Generate the DDR Code The following is the workflow of the DDR tool for the MX8MM series:   Preparation Board: i.MX 8M Mini LPDDR4 EVK Software download: mscale_ddr_tool_v3.31_setup.exe(Install it) PC:Window10 PC file .ds file Hardware requirements for the board: (Please note that these interfaces are necessary when using our stress testing tools) Serial download mode USB OTG port Debug UART port 4.1 Hardware connection   SW1101set 1010xxxxxx go to Serial Download mode, connect the USB-OTG and UART to PC, USB OTG is used for serial download of binary files: UART is used to communicate with users. Note: It is recommended to connect the USB OTG directly to the host PC, rather than through the USB Hub. When power on the board，we can see HID-compliant vendor-defined device and USB Input Device:   UART port are COM3 and COM4:   4.2 Open MSCALEDDR_Tool. exe in administrator mode for DDR parameter calibration and pressure testing：   Select serial port Select Search in Debug UART and you can read that the other two serial ports COM3 and COM4 have been tried. Click on the Connect button. It should be noted that we have two serial ports, one for the A core and the other for the M core. Here, COM4 must be selected to load the script normally. COM4 is used for the A core. Select Target Select the MX8M-mini，speed of CPU chosse1200MHZ, DDR LPDDR4 size 2GB. Select .ds file, Load DDR Script: Copy the generate mx8mm_micron_lpddr4_2gb_2d_1500m_200m_50m_32bit_1cs_RPAv22.ds to the path of the DDR TOOL, then press the Download button. After the download is successful, there will be a print message indicating the successful download and the startup information of the board. We can see the CPU parameters and DDR configuration.   Pres Calibration: This step mainly involves executing the DDR initialization and calibration process. If there is a failure, it is necessary to analyze the DDR problem based on the printed information. If there is no problem, the following interface will appear.   (5) If there are no problems after calibration, perform a pressure test. Only perform this operation when the calibration is passed. Run the test on all frequency set points. If the DDR pressure test passes, you can see that the test has passed successfully. If there is an error, you should search for the problem with the DDR based on the error message.   (6) Generate u-boot timing After the stress test is successfully completed, clicking the Gen Code button will generate a file lpddr4_timing. c, and then the lpddr4_timing. C file can be copied to the u boot directory.     5\ Modifying and configuring DDR frequencies that are not supported by default         The above test is for the frequency point 1500MHZ that is supported by default in our tool. RPA provides default DRAM PLL settings (DRAM frequency) based on the default settings supported in u-boot. If the customer is not using the default supported frequency, in addition to updating the new frequency in RPA, the new DRAM PLL settings should also be manually updated in the u boot SPL. (1) Firstly, in the RPA script, "Clock Cycle Freq (MHz)" is set to the frequency we need (2) Then search for 'memory set 0x30360054' in the RPA DDR stress test file worksheet tab, with a default setting of 1500MHZ.   We can see the DRAM PLL register and bit settings：   For special frequencies, we have a calculation formula here: DDR_freq = [(24MHz x pll_main_div)/(pll_pre_div x 2^pll_post_div)] x 2 1500 = [(24 x 250) / (8 x 2^1)] x 2 Bellow are some special examples of the required configurations for various frequencies:     Finishing configuration, create a. ds test DDR script in the RPA script to specify the frequency of this configuration. （3）After creating a DDR script for the DDR stress testing tool, run the calibration and perform the DDR pressure test. Generating the lpddr4_timing.c, modify the required DDR rate parameters Manually. （4）Modify the DRAM PLL，DRAM_freq = DRAM_PLL x 2 in SPL，u-boot SPL DDR driver can will not automatically change DRAM PLL based on generated code. Therefore, users will need to manually modify the dram_pll_init  for the required DDR PLL parameter.

On this tutorial we will review the implementation of Flutter on the i.MX8MP using the Linux Desktop Image. Please find more information about Flutter using the following link: Flutter: Option to create GUIs for Embedded System... - NXP Community Requirements: Evaluation Kit for the i.MX 8M Plus Applications Processor. (i.MX 8M Plus Evaluation Kit | NXP Semiconductors) NXP Desktop Image for i.MX 8M Plus (GitHub - nxp-imx/meta-nxp-desktop at lf-6.1.1-1.0.0-langdale) Note: This tutorial is based on the NXP Desktop Image with Yocto version 6.1.1 – Langdale. Steps: 1. First, run commands to update packages. $ sudo apt update $ sudo apt upgrade 2. Install Flutter for Linux using the following command. $ sudo snap install flutter --classic 3. Run the command to verify the correct installation. $ flutter doctor With this command you will find information about the installation. The important part for our purpose is the parameter "Linux toolchain - develop for Linux desktop". 4. Run the command “flutter create .” to create a flutter project, this framework will create different folders and files used to develop the application.  $ cd Documents $ mkdir flutter_hello $ cd flutter_hello $ flutter create .​ 5. Finally, you can run the “hello world” application using: $ flutter run Verify the program behavior incrementing the number displayed on the window.  

One of the most popular use cases for embedded systems are projects destinated to show information and interact with users. These views are called GUI or Graphic User Interface which are designed to be intuitive, attractive, consistent, and clear. There are many tools that we can use to achieve great GUIs, mostly implemented for platforms such as Web, Android, and iOS. Here, we will need to introduce the concept of framework, basically, it is a set of tools and rules that provides a minimal structure to start with your development. Frameworks usually comes with configuration files, code snippets, files and folders organization helping us to save time and effort. Also, it is important to review the concept of SDK or Software Development Kit which is a set of tools that allows to build software for specific platforms. Usually supplies debugging tools, documentation, libraries, API’s, emulators, and sample code. Flutter is an open-source UI software development kit by Google that help us to create applications with great GUIs on different platforms from a single codebase. Depends on the reference, you can find Flutter defined as a framework or SDK and both are correct, however, an SDK could be a best definition thanks to Flutter supplies a wide and complete package to create an application in which framework is also included. This article is aimed at those that are in a prototyping stage looking for a different tool to develop projects. Also, this article pretends to be a theoretical introduction explaining the most important concepts. However, is a good practice to learn more about reviewing the official documentation from Flutter. (Flutter documentation | Flutter) Here is the structure used throughout this article: What is Flutter? Flutter details Platforms Programming language Official documentation Flutter for embedded systems What is Flutter? Flutter was officially released by Google in December 2018 with a main aim, to give developers a tool to create applications natively compiled for mobile (Android, iOS), web and desktop (Windows, Linux) from a single codebase. It means that as a developer, Flutter will create a structure with minimal code, configuration files, build files for each operating system, manifests, etc. in which we will add our custom code and finally build this code for our preferred OS. For example, we can create an application to review fruit and vegetable information and compile for Android and iOS with the same code. A basic Flutter development process based on my experience looks like the following diagram: Flutter has the following key features: Cross-platform development. Flutter allows the developer to create applications for different platforms using a single codebase. It means that you will not need to recreate the application for each platform you want to support.   Hot-reload. This feature allows the developer to see changes in real time without restarting the whole application, this results in time savings for your project.   High Performance Flutter apps achieve high performance due to the app code is compiled to native ARM code. With this tool no interpreters are involved.   UI Widgets Flutter supplies a set of widgets (UI components such as boxes, inputs text, buttons, etc.) predefined by UI systems guidelines Material on Android and Cupertino for iOS. Source: Material 3 Design Kit | Figma Community Source: Design - Apple Developer   Great community support. This feature could be subjective but, it is useful when we are developing our project find solutions to known issues or report new ones. Because of Flutter is an open source and is widely implemented in the industry this tool owns a big community, with events, forums, and documentation. Flutter Details Supported Platforms With Flutter you can create applications for: Android iOS Linux Debian Linux Ubuntu macOS web Chrome, Firefox, Safari, Edge Windows Supported deployment platforms | Flutter Programming Language Flutter use Dart, a programming language is an open-source language supported by Google optimized to use on the creation of user interfaces. Dart key features: Statically typed. This feature helps catching errors making the code robust ensuring that the variable’s value always match with the declared variable’s type. Null safety. All variables on Dart are non-nullable which means that every variable must have a non-null value avoiding errors at execution time. This feature also, make the code robust and secure. Async/Await. Dart is client-optimized which means that this language was specially created to ensure the best performance as a client application. Async/Await is a feature part of this optimization making easier to manage network requests and other asynchronous operations. Object oriented. Dart is an object-oriented language with classes and mixin. This is especially useful to use on Flutter with the usage of widgets. Compiler support of Just-In-Time (JIT) and Ahead-of-Time (AOT) JIT provides the support that enables the Hot Reload Flutter feature that I mentioned before. It is a complex mechanism, but Dart “detects” changes in your code and execute only these changes avoiding recompiling all the code. AOT compiler produces efficient ARM code improving start up time and performance. Official documentation Flutter has a rich community and documentation that goes from UI guidelines to an Architectural Overview. You can find the official documentation at the following links: Flutter Official Documentation: Flutter documentation | Flutter Flutter Community: Community (flutter.dev) Dart Official Documentation: Dart documentation | Dart Flutter for embedded systems So far, we know all the excellent features and platforms that Flutter can support. But, what about the embedded systems? On the official documentation we can find that Flutter may be used for embedded systems but in fact there is no an official supported platform. This SDK has been supported by their community, specially there is one repository on GitHub supported by Sony that provides documentation and Yocto recipes to support Flutter on embedded Linux. To understand the reason to differentiate between Flutter for Linux Desktop with official support and to create a specific Flutter support for embedded Linux is important to describe the basics of Flutter architecture. Based on the Flutter documentation the system is designed using layers that can be illustrated as follows:   Source: Flutter architectural overview | Flutter We can see as a top level “Framework” which is a high-level layer that includes widgets, tools and libraries that are in contact with developers. Below “Framework,” the layer “Engine” is responsible of drawing the widgets specified in the previous layer and provides the connection between high-level and low-level code. This layer is mostly written in C++ for this reason Flutter can achieve high performance running applications. Specifically for graphics rendering Flutter implements Impeller for iOS and Skia for the rest of platforms. The bottom layer is “Embedder” which is specific for each target and operating system this layer allows Flutter application to run as a native app providing the access to interact with different services managed by the operating systems such as input, rendering surfaces and accessibility. This layer for Linux Desktop uses GTK/GDK and X11 as backend that is highly dependent of unnecessary libraries and expensive for embedded systems which have constrained resources for computation and memory. The work around founded by Sony’s Flutter for Embedded Linux repository is to change this backend using a widely implemented backend for embedded systems Wayland. The following image illustrates the difference between Flutter for Linux Desktop and Flutter for Embedded Linux.   Source: What's the difference between Linux desktop and Embedded Linux · sony/flutter-embedded-linux Wiki · GitHub   Source: What's the difference between Linux desktop and Embedded Linux · sony/flutter-embedded-linux Wiki · GitHub Here is the link to the mentioned repository: GitHub - sony/flutter-elinux: Flutter tools for embedded Linux (eLinux) Finally, I would like to encourage you to read the official Flutter documentation and consider this tool as a great option compared to widely used tools on embedded devices such as Qt or Chromium. Also, please have a look to a great article written by Payam Zahedi delving into the implementation of Flutter for Embedded Linux measuring performance and giving conclusions about the usage of Flutter in embedded systems. (Flutter on Embedded Devices. Learn how to run Flutter on embedded… | by Payam Zahedi | Snapp Embedded | Medium).    

Note: This guide is specifically for use with VS Code. For standalone with Segger software please refer to this guide. (How to Use Segger J-Link Plus with i.MX 8M Process... - NXP Community) In this guide we will describe the process to start using VS Code to debug an SDK application. The board used for this guide specifically is the i.MX 8M Nano EVK, but it also applies to all processors of the i.MX 8M Family. This guide covers the following topics: Hardware requirements Software requirements How to find, build, and download the i.MX SDK Debug Probe and i.MX 8M Nano EVK connection Create an SDK Application with MCUXpresso for VS Code Run and debug your SDK Application with MCUXpresso for VS Code Hardware requirements Evaluation Kit for the i.MX8M Nano Applications Processor (i.MX 8M Nano Evaluation Kit | NXP Semiconductors) Quick Start Guide for i.MX8M Nano (I.MX 8M Nano EVK Quick Start Guide (nxp.com)) J-Link Plus JTAG/SWD debug probe with USB interface (SEGGER J-Link PLUS) Features Download speed up to 1MB/s Unlimited breakpoints in flash memory Supports direct download into RAM and flash memory Supported NXP Devices Supported Devices - Search results "nxp" (segger.com) 9 Pin Cortex-M Adapter (9-Pin Cortex-M Adapter (segger.com)) Description Adapts from the 20-pin 0.1'' JTAG connector to a 9-pin 0.05'' Samtec FTSH connector as defined by Arm. Software requirements Windows 10 OS (host) J-Link Software and Documentation Pack for Windows (https://www.segger.com/products/debug-probes/j-link/models/j-link-plus/) i.MX 8M Nano SDK (Welcome | MCUXpresso SDK Builder (nxp.com)) VS Code for Windows (Installation Guide: Running Visual Studio Code on Windows) MCUXpresso Extension for VS Code (Installation Guide: Training: Walkthrough of MCUXpresso for VS Code - NXP Community)   How to find, build, and download the i.MX 8M Nano SDK Enter Welcome | MCUXpresso SDK Builder (nxp.com) Click on "Select Development Board"  Select EVK-MIMX8MN (MIMX8MN6xxxJZ) from Boards -> i.MX -> EVK-MIMX8MN Click on the Build MCUXpresso SDK button Click on Download SDK, you'll be redirected to the MCUXpresso SDK Dashboard Look for the i.MX 8M Nano SDK and click on Download SDK Click on Download SDK archive and documentation, accept the Software Terms and Conditions and the .zip file for the SDK will be downloaded. Debug Probe and i.MX 8M Nano EVK connection Connect the debug cable (USB-UART) to the board and the other end to your PC. Connect the power cable to the second USB-C port and to a wall socket. Don't turn on the board yet. Connect the JLink Plus to your PC with the USB cable. Connect the JLink Plus to the JTAG of the i.MX 8M Nano EVK board In this part we will need to identify pin number 1 from the 9 Pin Cortex-M adapter and from the i.MX 8M Nano EVK board. For the first one identifies pin 7 identifiable by a "non-connect pin". For the i.MX 8M Nano, you can identify easily with a number 1 in one corner of the connectors.    The whole setup should look similar to this:   Create an SDK Application with MCUXpresso for VS Code Before delving into the details of creating an SDK Application it is important to recognize the sections of VS Code User Interface. This will help us to describe accurately the buttons' position. Click on MCUXpresso for VS Code extension icon from the Activity Bar.  In the section “Quickstart Panel” located in the Side Bar click on “Import Repository.” On this window, go to “Local” and select your previously downloaded SDK folder location. Then, click on “Import.” Expand the section “Installed Repositories” from Side Bar and verify your selected SDK. Expand the section “Projects” from Side Bar and click on “Import Example from Repository” and complete the options: Choose a toolchain Choose a board Choose a template Name Location Finally, click on the "Create" button. Click on the gear icon located in the project folder to build the code. In “Projects” expand the “Settings” options and select “mcuxpresso-tools.json.” Here you will find a JSON file with different parameters. Defines the device that will be used to connect with the J-Link Plus. Code: “segger”: { “device”: “MIMX8MN6_M7” } Expand the section “Debug Probes” and verify that your J-Link Plus debug probe appears. Start SEGGER J-Link GDB Server. On section “Target Device” select MIMX8MN6_M7 and click “OK”. You will see the following window. Run and debug your SDK Application with MCUXpresso for VS Code Click on “Debug” located in the project folder, to start with the debugging session. In the Panel click on “Serial Monitor,” set it to the serial debug port with the lowest numbered port with the following settings: Baud rate: 115200 Line ending: None Click on "Start Monitoring" Use the debug controls to run the code. Verify your code output in the “Serial Monitor.”

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.