The i.MX6UL/LL/LZ processor supports 2 USB OTG interfaces, USB OTG1 and USB OTG2, and each USB interface can be configured as a device, host or dual role mode. On the EVK board of i.MX6UL/LL, USB OTG1 is designed as dual role mode, and USB OTG2 is designed as HOST mode. This is sufficient for most customers.       However, in actual applications, we may need 2 USB HOSTs, and at the same time, we don’t want to use MicroUSB to USB TYPE-AF cable for Host-Device mode conversion. Therefore, the design of the USB circuit needs to meet such requirements: 1. USB device mode We need a USB device to download the linux image to the flash or SD card on the board. 2. 2 USB HOSTs When the system is working normally, we need the board to support 2 USB HOST. i.MX6UL/LL/LZ has only 2 USB ports. How to design to meet this requirement without increasing the USB HUB? The following scheme is used as a reference, and I hope it will be helpful to customers with similar requirement:        The logic and application description of this Diagram:: Default—device mode In the process of debugging the software, we need to use the USB OTG interface to download the linux image, so it must work in device mode. What we need to do is: (1). Pull USB OTG ID up to 3.3V (2). The USB OTG D+/D- signal is switched to the MicroUSB connector. (3). The USB OTG VBUS is provided with 5V power from the external PC USB HOST. Usage:        -Use a jumper for Pin 1 and Pin2, USB OTG ID pin will be pulled up to High.        With the operation, SEL pin of USB Muxer is High, and USB signals are switched to port B, and USB differential signals are connected to MicroUSB connector. At the same time, MIC2026-1YM output is disabled. The USB OTG1 VBUS pin of CPU is supplied by VBUS of MicroUSB connector, that is to say, supplied by PC USB HOST.        In this mode, software engineer can use it to download images to flash on board. Normal Work—Host mode After the software debugging is completed, two HOSTs are needed on the board. At this time, we need to switch the USB OTG1 from device to HOST mode. What we need to do is: (1). Pull USB OTG1 ID down to LOW (2). The USB OTG D+/D- signal is switched to the USB Type-AF connector. (3). Board should supply 5V power for USB device connected USB Type-AF connector. Usage:        -Use a jumper for Pin 2 and Pin3, USB OTG ID pin will be pulled down to Low.        With the operation, USB OTG1 ID pin is pulled down to Low, SEL pin of USB Muxer is also LOW, USB signals are switched to Port A, and connected to USB type-AF connector. At the same time, MIC2026-1YM is enabled , OUTA will output 5V , which will supply USB device connected on USB type-AF connector.   [Note] Users need to pay attention to. When using the jumper with PIN1/2/3, the board needs to be powered off. In other words, when switching between device and host, you need to switch off the power, then power on, and restart the board. The solution can also be used for i.MX processors with USB 2.0 interface.   NXP CAS team Wedong Sun 01/15/2021

Recently, some customers are using i.MX processor, they want to add raid & LVM function support to the kernel, but they have encountered the problem that the compilation cannot pass. Tested it in L4.14.98, L4.19.35 & L5.4.x, Only L4.14.98 bsp exists the problem. Here are the experimental steps I have done, including the same problems I encountered with the customer, and how to modify the kernel to ensure that the compilation passes. 1. Exporting cross compilation tool chain from yocto BSP (1) Downloading Yocto BSP and compiling it. Following steps in i.MX_Yocto_Project_User's_Guide.pdf, download Yocto BSP and compile it successfully. (2) Exporting cross compilation tool chain Following methods described in i.MX_Linux_User's_Guide.pdf, export cross compilation tool chain from yocto BSP. See Chapter 4.5.12 of the document, please! Then cross compilation tool chain will be like below: (3) Copying linux BSP source code to a new directory # cd ~ # mkdir L4.14.98-2.0.0 # cd L4.14.98-2.0.0 # cp -r ~/imx-yocto-bsp/build-fb/tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/4.14.98- r0/git ./ Then all linux source code has been copied to L4.14.98-2.0.0, which is the top directory of linux kernel source code, I will compile kernel image here. 2. Compiling linux kernel # cd ~/L4.14.98-2.0.0 # source /opt/fsl-imx-fb/4.14-sumo/environment-setup-cortexa9hf-neon-poky-linux-gnueabi # export ARCH=arm # make imx_v7_defconfig # make menuconfig Then we will add RAID and LVM modules to linux kernel. In order to reproduce errors, I added all related modules to kernel. See below, please! Device drivers---->Multiple devices driver support (RAID and LVM) After save and exit, began to compile kernel. # make (make –j4) The following errors will occur: ------------------------------------------------------------------------------------------- drivers/md/dm-rq.c: In function ‘dm_old_init_request_queue’: drivers/md/dm-rq.c:716:2: error: implicit declaration of function ‘elv_register_queue’; did you mean ‘blk_register_queue’? [-Werror=implicit-function-declaration] elv_register_queue(md->queue); ^~~~~~~~~~~~~~~~~~ blk_register_queue cc1: some warnings being treated as errors scripts/Makefile.build:326: recipe for target 'drivers/md/dm-rq.o' failed make[2]: *** [drivers/md/dm-rq.o] Error 1 scripts/Makefile.build:585: recipe for target 'drivers/md' failed make[1]: *** [drivers/md] Error 2 Makefile:1039: recipe for target 'drivers' failed make: *** [drivers] Error 2 ------------------------------------------------------------------------------------------- 3. Finding out root cause and solving it (1) elv_register_queue( ) function The function is loaded in dm-rq.c : int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t) { … … elv_register_queue(md->queue); … … } BUT compiler didn’t find it’s declaration and entity. Searching source code, and found it declared in linux_top/block/blk.h: … … int elv_register_queue(struct request_queue *q); … … It’s entity is in linux_top/block/elevator.c: int elv_register_queue(struct request_queue *q) { … … } (2) Adding declaration and exporting the function --- Declaration Add the line below to dm-rq.c: … … extern int elv_register_queue(struct request_queue *q); … … --- Exporting the function(elevator.c) Add EXPORT_SYMBOL(elv_register_queue); to the end of function, see below. int elv_register_queue(struct request_queue *q) { … … } EXPORT_SYMBOL(elv_register_queue); 4. Re-compiling Linux Kernel The above error will not occur and the compilation will complete successfully.   NXP CAS team Weidong Sun

Hello everyone, In this document I'll explain on how to build the UUU (Universal Update Utility) using windows 10 PC. This may be useful in case of adding custom commands to run during the flash using built-in scripts, be it for debugging, fuse blowing, etc. First we need to download and install Visual Studio community, for this guide I'll use community 2019, version it is available here: https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=Community&rel=16 For workloads select Universal Windows Platform development.   When installing, make sure to select and install the Git for windows complement, at the top select Individual components, this will display a new list, scroll down to code tools and you will find Git for windows, check this box In case Visual Studio is already installed, you may open the installer again and chose modify, this will let you install the complement as well. After the installation is complete we may run the git commands on the power shell. Now open the windows power shell and type the following commands: git clone https://github.com/NXPmicro/mfgtools.git // clones the MFGTool (UUU) source code from the github cd mfgtools // enters the mfgtools folder we just cloned git submodule init // creates the local configuration file for the submodules git submodule update // set the submodules to the commit specified by the main repository. At this point we can edit the built in scripts to add our custom commands, for this guide I'll add the printenv uboot command at the end of the flashing process. For this I'll enter the folder mfgtools/uuu, and edit emmc_burn_all.lst with any text editor, i.e. Notepad ++, add the command FB: ucmd printenv.   Save and close the editor, it is possible to add most uboot commands like for example the fuse commands to burn eFuses. Then we can now build the tool, opening msvc/uuu-static-link.sln with Visual studio, select solution uuu-static-link.sln   And finally build the solution: The executable (uuu.exe) would be at the following path: mfgtools\msvc\x64\Debug   Finally we run the built in script we modified and check the results. Find attached both the powershell and uboot logs, I tested this using an i.MX8MN with L5.4.47_2.2.0, running the following command: ./uuu.exe -v -b emmc_all imx-boot-imx8mnevk-sd.bin-flash_evk imx-image-full-imx8mnevk.wic Hope this may found useful for anyone trying to achieve something similar.

Description       This doc explain how to enable the plugin boot on i.MX6Q/6DL and which used for change the pll2 clock and add the spread spectrum support to pass the EMI test. we still list the source codes of 3.0.35 and 4.1.15. to explain the dts/non-dts kernel support.       本文旨在说明如何在i.MX6Q/6DL上实现plugin启动，以支持展频和改变pll2的频率，其目的是为了通过 EMI测试。也附上了基于3.0.35和4.1.15的源代码，以供参考   Products Product Category NXP Part Number URL MPU i.MX6 Family https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-processors/i-mx-6-processors:IMX6X_SERIES   Tools NXP Development Board URL i.MX6 SabreSDP https://www.nxp.com/design/development-boards:EVDEBRDSSYS#/collection=softwaretools&start=0&max=25&query=typeTax%3E%3Et633::archived%3E%3E0::Sub_Asset_Type%3E%3ETSP::deviceTax%3E%3Ec731_c380_c127_c126&sorting=Buy%2FSpecifications.desc&language=en&siblings=false          Version: MX6Q_PLUGIN_FC_SSC_V7-20200915_chn..pdf（chinese version）add baidou support MX6Q_PLUGIN_FC_SSC_V7-20170504_eng-chapter-imx6dl.doc+MX6Q_PLUGIN_FC_SSC_V3-20170309_eng.doc（english version）