Inside IPU there are two block where color space conversion can be made: IC (Image Converter) and DP (Display processor). On Linux, the CSC parameters are located at IPU (IC and DP) drivers, linux/drivers/mxc/ipu3 folder. All negative coefficients are represented using two's complement. Linux Image Converter driver: The parameters are set on function _init_csc: http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/drivers/mxc/ipu3/ipu_ic.c?h=imx_3.14.28_1.0.0_ga static void _init_csc(struct ipu_soc *ipu, uint8_t ic_task, ipu_color_space_t in_format, ipu_color_space_t out_format, int csc_index) { /* * Y = 0.257 * R + 0.504 * G + 0.098 * B + 16; * U = -0.148 * R - 0.291 * G + 0.439 * B + 128; * V = 0.439 * R - 0.368 * G - 0.071 * B + 128; */ static const uint32_t rgb2ycbcr_coeff[4][3] = { {0x0042, 0x0081, 0x0019}, {0x01DA, 0x01B6, 0x0070}, {0x0070, 0x01A2, 0x01EE}, {0x0040, 0x0200, 0x0200}, /* A0, A1, A2 */ }; /* transparent RGB->RGB matrix for combining */ static const uint32_t rgb2rgb_coeff[4][3] = { {0x0080, 0x0000, 0x0000}, {0x0000, 0x0080, 0x0000}, {0x0000, 0x0000, 0x0080}, {0x0000, 0x0000, 0x0000}, /* A0, A1, A2 */ }; /* R = (1.164 * (Y - 16)) + (1.596 * (Cr - 128));   G = (1.164 * (Y - 16)) - (0.392 * (Cb - 128)) - (0.813 * (Cr - 128));   B = (1.164 * (Y - 16)) + (2.017 * (Cb - 128); */ static const uint32_t ycbcr2rgb_coeff[4][3] = { {149, 0, 204}, {149, 462, 408}, {149, 255, 0}, {8192 - 446, 266, 8192 - 554}, /* A0, A1, A2 */ }; ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Linux Display Processor driver: The parameters are set on constants (rgb2ycbcr_coeff and ycbcr2rgb_coeff): http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/drivers/mxc/ipu3/ipu_disp.c?h=imx_3.14.28_1.0.0_ga /* Y = R * 1.200 + G * 2.343 + B * .453 + 0.250;   U = R * -.672 + G * -1.328 + B * 2.000 + 512.250.;   V = R * 2.000 + G * -1.672 + B * -.328 + 512.250.;*/ static const int rgb2ycbcr_coeff[5][3] = { {0x4D, 0x96, 0x1D}, {-0x2B, -0x55, 0x80}, {0x80, -0x6B, -0x15}, {0x0000, 0x0200, 0x0200}, /* B0, B1, B2 */ {0x2, 0x2, 0x2}, /* S0, S1, S2 */ }; /* R = (1.164 * (Y - 16)) + (1.596 * (Cr - 128));   G = (1.164 * (Y - 16)) - (0.392 * (Cb - 128)) - (0.813 * (Cr - 128));   B = (1.164 * (Y - 16)) + (2.017 * (Cb - 128); */ static const int ycbcr2rgb_coeff[5][3] = { {0x095, 0x000, 0x0CC}, {0x095, 0x3CE, 0x398}, {0x095, 0x0FF, 0x000}, {0x3E42, 0x010A, 0x3DD6}, /*B0,B1,B2 */ {0x1, 0x1, 0x1}, /*S0,S1,S2 */ };‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

BlueZ5 provides support for the core Bluetooth layers and protocols. It is flexible, efficient and uses a modular implementation. BlueZ5 has implemented the Bluetooth low level host stack for Bluetooth core specification 4.0 and 3.0+HS which includes GAP, L2CAP, RFCOMM, and SDP. Besides the host stack, BlueZ5 has also supported the following profiles itself or via a third party software. Profiles provided by BlueZ: A2DP 1.3 AVRCP 1.5 DI 1.3 HDP 1.0 HID 1.0 PAN 1.0 SPP 1.1 GATT (LE) profiles: PXP 1.0 HTP 1.0 HoG 1.0 TIP 1.0 CSCP 1.0 OBEX based profiles (by obexd): FTP 1.1 OPP 1.1 PBAP 1.1 MAP 1.0 Provided by the oFono project: HFP 1.6 (AG & HF)Supported Profiles BlueZ5 has been supported in the latest Freescale Linux BSP release, so it would be pretty easy to generate the binaries for Bluetooth core stack and its profiles. In order to support A2DP sink on a SabreSD board, the following software should be downloaded and installed onto the target rootfs too. sbc decoder version 1.3 (http://www.kernel.org/pub/linux/bluetooth/sbc-1.3.tar.gz) PulseAudio 5.0 (http://www.freedesktop.org/software/pulseaudio/releases/pulseaudio-5.0.tar.xz) PulseAudio package has some dependencies with bluetooth and sbc packages, and pulseaudio will detect if the two packages have been built and then decide which pulse plugin modules to be generated. So the building order will be 1) bluez5_utils or bluez_utils   2) sbc   3) pulseaudio. After compile and install the above software onto the target rootfs, you should be able to see the following executable under the directory /usr/bin From BlueZ5: bluetoothctl, hciconfig, hciattach (Needed by operating a UART bluetooth module) From PulseAudio: pulseaudio, pactl, paplay If the building dependency has been setup correctly, the following pulse plugin modules should be located under the directory /usr/lib/pulse-5.0/modules module-bluetooth-discover.so      module-bluetooth-policy.so        module-bluez5-device.so   module-bluez5-discover.so Edit the file /etc/dbus-1/system.d/pulseaudio-system.conf, and add the following lines in red: <policy user="pulse">     <allow own="org.pulseaudio.Server"/>    <allow send_destination="org.bluez"/>     <allow send_interface="org.freedesktop.DBus.ObjectManager"/> </policy> Edit the file /etc/dbus-1/system.d/bluetooth.conf, and add the following lines: <policy user="pulse">      <allow send_destination="org.bluez"/>      <allow send_interface="org.freedesktop.DBus.ObjectManager"/> </policy> Adding the following settings at the bottom of the pulseaudio system configuration file which locates in /etc/pulse/system.pa ### Automatically load driver modules for Bluetooth hardware .ifexists module-bluetooth-policy.so load-module module-bluetooth-policy .endif .ifexists module-bluetooth-discover.so load-module module-bluetooth-discover .endif load-module module-switch-on-connect load-module module-alsa-sink device_id=0 tsched=true tsched_buffer_size=1048576 tsched_buffer_watermark=262144 On the system that can automatically detect the alsa cards, the above line #13 should be removed.  Also make sure "auth-anonymous=1" is added to the following line, which can resolve the issue: "Denied access to client with invalid authorization data". load-module module-native-protocol-unix auth-anonymous=1 Selecting a audio re-sampling algorithm and configuring the audio output by adding the following settings to the file daemon.conf locating in /etc/pulse resample-method = trivial enable-remixing = no enable-lfe-remixing = no default-sample-format = s16le default-sample-rate = 48000 alternate-sample-rate = 24000 default-sample-channels = 2 Pulseaudio can be started as a daemon or as a system-wide instance. To run PulseAudio in system-wide mode, the program will automatically drop privileges from "root" and change to the "pulse" user and group. In this case, before launching the program, the "pulse" user and group needs to be created on the target system.  In the example below, "/var/run/pulse" is the home directory for "pulse" user. adduser -h /var/run/pulse pulse addgroup pulse-access adduser pulse pulse-access Because PulseAudio needs to access the sound devices, add the user "pulse" to the "audio" group too. adduser pulse audio Starting bluetoothd and pulseaudio: /usr/libexec/bluetooth/bluetoothd -d & pulseaudio --system --realtime & To verify if the pulseaudio has been set up correctly, you can play a local wave file by using the following command. If you can hear the sound, the system should have been configured correctly. paplay -vvv audio8k16S.wav After setting up the pulseaudio, launch bluetoothctl to pair and connect to a mobile phone. After connecting to a mobile phone, you should be able to see the following information in bluetoothctl console: [bluetooth]# show Controller 12:60:41:7F:03:00         Name: BlueZ 5.21         Alias: BlueZ 5.21         Class: 0x1c0000         Powered: yes         Discoverable: no         Pairable: yes         UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)         UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)         UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)         UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)         UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)         UUID: Message Notification Se.. (00001133-0000-1000-8000-00805f9b34fb)         UUID: Message Access Server     (00001132-0000-1000-8000-00805f9b34fb)         UUID: Phonebook Access Server   (0000112f-0000-1000-8000-00805f9b34fb)         UUID: IrMC Sync                 (00001104-0000-1000-8000-00805f9b34fb)         UUID: OBEX File Transfer        (00001106-0000-1000-8000-00805f9b34fb)         UUID: OBEX Object Push          (00001105-0000-1000-8000-00805f9b34fb)         UUID: Vendor specific           (00005005-0000-1000-8000-0002ee000001)         UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)         UUID: Audio Sink                (0000110b-0000-1000-8000-00805f9b34fb)         Modalias: usb:v1D6Bp0246d0515         Discovering: no If you can see the audio sink UUID, you are ready to enjoy the bluetooth music now.

Some customer need to know how to add support RS485 mode half duplex? Here give some recommends. About i.MX6 UART to RS485 applications 1. Using RS485 mode of UART directly. On hardware, you should use UART_CTS_B to control RX & TX. On software, The link for you reference: Does UART in RS485 mode support only 9 Bit mode for i.MX6 ?  2. Sensing IO direction Automatically via hardware, don't need to tune software. For i.MX8QXP As the linux BSP for i.MX8QXP do not support RS 485 mode, so for the RS 485 using you can use the Sensing IO direction Automatically via hardware, don't need to tune software. As the above i.MX6 design.

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-344336 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-344462 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-345680 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-345148 

         In recent months, some I.MX customers hope to compile u-boot-fw-utils in yocto and get fw_printenv & fw_setenv tools.          Although there are u-boot-fw-utils bblayers in Yocto recipes, by default, u-boot-fw-utils is not based on u-boot-imx, but downloaded from the u-boot source website, when using bitbake When u-boot-fw-utils compiles it, it will fail to compile.          For example: # cd  ~/imx-yocto-bsp-5.4.3_1.0.0 # DISTRO=fsl-imx-fb MACHINE=imx6sxsabresd source imx-setup-release.sh -b build_sabresd # bitbake u-boot-fw-utils -c compile          If changing .config to be mx6sxsabresd_optee_defconfig in the top directory of u-boot source code, new errors will occur, like descriptions in the link:          https://community.nxp.com/message/1318081?commentID=1318081#comment-1318081            The root cause is that the u-boot is not u-boot-imx.          If we did the test below, it is easy to validate it.      Compiling u-boot # bitbake u-boot-imx -c compile          After compilation is done, u-boot-imx source code will be released .      Changing u-boot source code of u-boot-fw-utils directory          Replace u-boot source code in u-boot-fw-utils directory with u-boot-imx source code. Then continue to compile u-boot-fw-utils # bitbake u-boot-fw-utils -c compile          We will find it can be compiled successfully. This shows that when u-boot-fw-utils is compiled, the downloaded u-boot source code must be u-boot-imx.          In order to achieve this, we need to add recipes to yocto's u-boot-imx, and we can successfully compile fw_printevn and fw_setenv through the bitbake command. Please follow these steps to add u-boot-fw-utils for i.mx to yocto! copy 2 files in attacments to ~/imx-yocto-bsp-5.4.3_1.0.0/sources/meta-imx/meta-bsp/recipes-bsp/u-boot cd ~/imx-yocto-bsp-5.4.3_1.0.0 run below comands # DISTRO=fsl-imx-fb MACHINE=imx6sxsabresd source imx-setup-release.sh -b build_sabresd # bitbake u-boot-imx-fw-utils -c compile # bitbake u-boot-imx-fw-utils -c install   Then you will get fw_printenv & fw_setenv [Comment]          If i.MX users are using other version of linux BSP, she only need to modify the following content of u-boot-imx-common_2019.04.inc to compile u-boot-fw-utils. …… LIC_FILES_CHKSUM = "file://Licenses/gpl-2.0.txt;md5=b234ee4d69f5fce4486a80fdaf4a4263"   UBOOT_SRC ?= "git://source.codeaurora.org/external/imx/uboot-imx.git;protocol=https" SRCBRANCH = "lf-5.4.y_v2019.04" SRC_URI = "${UBOOT_SRC};branch=${SRCBRANCH} \ " SRCREV = "228843cdf5435d4bd69f42a6015f78761ff4cc0d" ……          Then compile it following above steps.          Example for L4.14.98_2.0.0: 1.Copy u-boot-imx-common_2019.04.inc & u-boot-imx-fw-utils_2019.04.bb to ~/imx-release-bsp-4.14.98-2.0.0/sources/meta-fsl-bsp-release/imx/meta-bsp/recipes-bsp/u-boot/ 2.Rename files name according to u-boot version u-boot-imx-common_2018.03.inc     u-boot-imx-fw-utils_2018.03.bb 3.Modifying u-boot-imx-common_2018.03.inc In the directory, there is u-boot-imx_2018.03.bb file, open it, and find the link of u-boot and check sum, and use lines below to replace those lines in u-boot-imx-common_2018.03.inc In u-boot-imx_2018.03.bb file: …… LICENSE = "GPLv2+" LIC_FILES_CHKSUM = "file://Licenses/gpl-2.0.txt;md5=b234ee4d69f5fce4486a80fdaf4a4263"   UBOOT_SRC ?= "git://source.codeaurora.org/external/imx/uboot-imx.git;protocol=https" SRCBRANCH = "imx_v2018.03_4.14.98_2.0.0_ga" SRC_URI = "${UBOOT_SRC};branch=${SRCBRANCH}" SRCREV = "87a19df5e462f1f63e8a6d2973c7fb9e95284d04" …… Then in u-boot-imx-common_2018.03.inc, there is the same contents as above: Save it and exit. Go back to the top directory of yocto: ~/imx-release-bsp-4.14.98-2.0.0 # cd ~/imx-release-bsp-4.14.98-2.0.0 # DISTRO=fsl-imx-fb MACHINE=imx6sxsabresd source fsl-setup-release.sh -b build_sabresd # bitbake u-boot-imx-fw-utils -c compile # bitbake u-boot-imx-fw-utils -c install          The same method can be used for other Linux BSP versions.       NXP TIC Team Weidong Sun 05/28/2020

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-342174 

The document to descript change the u-boot environment variables under the Linux rootfs.  Also provide a demo on i.MX6ull evk of sdcard mirror.  Linux fw_printenv fw_setenv to access U-Boot's environment variables.pdf  --- the document fw_printenv_fw_setenv_demo_iMX6ullevk_L4.14.98_2.0.0_ga.sdcard  --- demo sdcard mirror

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-342877 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-342833 

L5.4.3_1.0.0 release is now available on IMX_SW landing page: BSP Updates and Releases -> Linux ->Linux L5.4.3_1.0.0. Documentation -> Linux -> Linux 5.4.3_1.0.0 Documentation Files available: # Name Description 1 imx-yocto-LF_L5.4.3_1.0.0.zip i.MX L5.4.3_1.0.0 for Linux BSP Documentation. Includes Release Notes, User Guide. 2 LF_v5.4.y-1.0.0_images_MX6QPDLSOLOX.zip i.MX 6QuadPlus, i.MX 6Quad, i.MX 6DualLite, i.MX 6Solox Linux Binary Demo Files 3 LF_v5.4.y-1.0.0_images_MX6SLLEVK.zip i.MX 6SLL EVK Linux Binary Demo Files 4 LF_v5.4.y-1.0.0_images_MX6UL7D.zip i.MX 6UltraLite EVK, 7Dual SABRESD, 6ULL EVK Linux Binary Demo Files 5 LF_v5.4.y-1.0.0_images_MX7ULPEVK.zip i.MX 7ULP EVK Linux Binary Demo Files  6 LF_v5.4.y-1.0.0_images_MX8MMEVK.zip i.MX 8M Mini EVK Linux Binary Demo Files  7 LF_v5.4.y-1.0.0_images_MX8MNEVK.zip i.MX 8M Nano EVK Linux Binary Demo Files  8 LF_v5.4.y-1.0.0_images_MX8MQEVK.zip i.MX 8M Quad EVK Linux Binary Demo files 9 LF_v5.4.y-1.0.0_images_MX8QMMEK.zip i.MX 8QMax MEK Linux Binary Demo files 10 LF_v5.4.y-1.0.0_images_MX8QXPMEK.zip i.MX 8QXPlus MEK Linux Binary Demo files 11 imx-scfw-porting-kit-1.2.10.1.tar.gz System Controller Firmware (SCFW) porting kit v1.2.10.1 for L5.4.3_1.0.0   Target board: MX 8 Series MX 8QuadXPlus MEK Board MX 8QuadMax MEK Board MX 8M Quad EVK Board MX 8M Mini EVK Board MX 8M Nano EVK Board MX 7 Series MX 7Dual SABRE-SD Board MX 7ULP EVK Board MX 6 Series MX 6QuadPlus SABRE-SD and SABRE-AI Boards MX 6Quad SABRE-SD and SABRE-AI Boards MX 6DualLite SDP SABRE-SD and SABRE-AI Boards MX 6SoloX SABRE-SD MX 6UltraLite EVK Board MX 6ULL EVK Board MX 6ULZ EVK Board MX 6SLL EVK Board   What’s New/Features: Please consult the Release Notes.   Known Issues: For known issues and more details please consult the Release Notes.   More information on changes of Yocto, see: README: https://source.codeaurora.org/external/imx/imx-manifest/tree/README?h=imx-linux-zeus ChangeLog: https://source.codeaurora.org/external/imx/imx-manifest/tree/ChangeLog?h=imx-linux-zeus      

Recently many customers faced the issue about connecting the git.freesacle .com failed when they built old bsp version like 4.1.15 or 3.14.52,  when the customer repo init according to the yocto user guide, they get the error message like ： repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-4.1-krogoth manifests:  escale.com[0: 192.88.156.202]: errno=Connection refused  fatal: cannot obtain manifest git://git.freescale.com/imx/fsl-arm-yocto-bsp.git ///// git clone git://git.freescale.com:9418/imx/fsl-arm-yocto-bsp.git -b imx-4.1.15-1.0.0_ga Cloning into 'fsl-arm-yocto-bsp'... fatal: unable to connect to git.freescale.com: git.freescale.com[0: 192.88.156.202]: errno=Connection refused the reason is that the old bsp source code was moved to "https://source.codeaurora.org/external/imx", customer needs to change "git://git.freescale.com/imx"  to "https://source.codeaurora.org/external/imx", for new repo init commands, try to use the commands like “repo init -u https://source.codeaurora.org/external/imx/fsl-arm-yocto-bsp -b <branch> [-m <manifest>]” for example: 4.1.15_1.0.0: repo init -u https://source.codeaurora.org/external/imx/fsl-arm-yocto-bsp -b imx-4.1.15-1.0.0_ga 4.1.15_2.0.0: repo init -u https://source.codeaurora.org/external/imx/fsl-arm-yocto-bsp -b imx-4.1-krogoth -m imx-4.1.15-2.0.0.xml 4.1.15_2.1.1: repo init -u https://source.codeaurora.org/external/imx/fsl-arm-yocto-bsp -b imx-4.1-krogoth -m imx-4.1.15-2.1.1.xml then you can "repo sync" and "bitbake", but some customers still has the connection error on building firmware-imx package, the error message like : ERROR: firmware-imx-1_5.4-r0 do_fetch: Fetcher failure: Fetch command failed with exit code 128, output: Cloning into bare repository '/opt/yocto/fsl-release-bsp/downloads//git2/git.freescale.com.imx.imx-firmware.git'... fatal: unable to connect to git.freescale.com: git.freescale.com[0: 192.88.156.202]: errno=Connection refused ERROR: firmware-imx-1_5.4-r0 do_fetch: Function failed: Fetcher failure for URL: 'git://git.freescale.com/imx/imx-firmware.git;branch=master;destsuffix=/opt/yocto/fsl-release-bsp/fsl_build_x11/tmp/work/cortexa9hf-neon-mx6qdl-poky-linux-gnueabi/firmware-imx/1_5.4-r0/firmware-imx-5.4/git'. Unable to fetch URL from any source. this reason is that 4.1.15 needs to download git2 package from git.freescale.com, then I uploaded the firmwar-imx git2 package, try to unzip first, then put packages under downloads/git2, then "bitbake firmware-imx" again

[中文翻译版] 见附件   原文链接： i.MX Create Android SDCard Mirror 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-343079 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-343046 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-343116 

[中文翻译版] 见附件   原文链接： Guide to flash an eMMC from SD Card on i.MX6Q SABRE-SD