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

All below changes are done based on imx_android-10.0_5.4.y. mek_8qm enable uSD 8987 wifi            1. hardware rework                no hardware rework required            2. patches The patch is attached as 0001-8qm-usd-8987-wifi.patch mek_8qm enable M.2 8987 wifi            1. hardware rework                no hardware rework required            2. patches The patch is attached as 0001-8qm-m2-8987-wifi.patch evk_8mq enable uSD 8987 wifi            1. hardware rework                no hardware rework required            2. patches diff --git a/imx8m/evk_8mq/BoardConfig.mk b/imx8m/evk_8mq/BoardConfig.mk index db7c4991..4d130cc0 100644 --- a/imx8m/evk_8mq/BoardConfig.mk +++ b/imx8m/evk_8mq/BoardConfig.mk @@ -136,7 +136,8 @@ ifeq ($(TARGET_USE_DYNAMIC_PARTITIONS),true) TARGET_BOARD_DTS_CONFIG ?= imx8mq:imx8mq-evk-no-product.dtb else # imx8mq with HDMI display - TARGET_BOARD_DTS_CONFIG ?= imx8mq:imx8mq-evk-pcie1-m2.dtb + TARGET_BOARD_DTS_CONFIG ?= imx8mq:imx8mq-evk-usd-wifi.dtb + # imx8mq with MIPI-HDMI display TARGET_BOARD_DTS_CONFIG += imx8mq-mipi:imx8mq-evk-lcdif-adv7535.dtb # imx8mq with HDMI and MIPI-HDMI display diff --git a/imx8m/evk_8mq/SharedBoardConfig.mk b/imx8m/evk_8mq/SharedBoardConfig.mk index 330ab1c5..a6654bad 100644 --- a/imx8m/evk_8mq/SharedBoardConfig.mk +++ b/imx8m/evk_8mq/SharedBoardConfig.mk @@ -7,10 +7,10 @@ PRODUCT_IMX_TRUSTY := true #Enable this to disable product partition build. #IMX_NO_PRODUCT_PARTITION := true -#NXP 8997 wifi driver module +# NXP 8987 wifi driver module BOARD_VENDOR_KERNEL_MODULES += \ - $(KERNEL_OUT)/drivers/net/wireless/marvell/mrvl8997/wlan_src/mlan.ko \ - $(KERNEL_OUT)/drivers/net/wireless/marvell/mrvl8997/wlan_src/pcie8xxx.ko + $(KERNEL_OUT)/drivers/net/wireless/nxp/mxm_wifiex/wlan_src/mlan.ko \ + $(KERNEL_OUT)/drivers/net/wireless/nxp/mxm_wifiex/wlan_src/moal.ko # mipi-panel touch driver module BOARD_VENDOR_KERNEL_MODULES += \ diff --git a/imx8m/evk_8mq/UbootKernelBoardConfig.mk b/imx8m/evk_8mq/UbootKernelBoardConfig.mk index 5aa1ce35..4c3378f0 100644 --- a/imx8m/evk_8mq/UbootKernelBoardConfig.mk +++ b/imx8m/evk_8mq/UbootKernelBoardConfig.mk @@ -14,7 +14,7 @@ endif TARGET_BOOTLOADER_CONFIG += imx8mq-evk-uuu:imx8mq_evk_android_uuu_defconfig TARGET_KERNEL_DEFCONFIG := imx_v8_android_defconfig -# TARGET_KERNEL_ADDITION_DEFCONF ?= android_addition_defconfig +TARGET_KERNEL_ADDITION_DEFCONF ?= android_addition_defconfig diff --git a/imx8m/evk_8mq/android_addition_defconfig b/imx8m/evk_8mq/android_addition_defconfig new file mode 100644 index 00000000..f51bd5ff --- /dev/null +++ b/imx8m/evk_8mq/android_addition_defconfig @@ -0,0 +1,2 @@ +CONFIG_WLAN_VENDOR_NXP=y +CONFIG_MXMWIFIEX=m diff --git a/imx8m/evk_8mq/early.init.cfg b/imx8m/evk_8mq/early.init.cfg index 9262d953..70097a1c 100644 --- a/imx8m/evk_8mq/early.init.cfg +++ b/imx8m/evk_8mq/early.init.cfg @@ -1,3 +1,3 @@ insmod vendor/lib/modules/mlan.ko -insmod vendor/lib/modules/pcie8xxx.ko sta_name=wlan uap_name=wlan wfd_name=p2p max_vir_bss=1 cfg80211_wext=0xf cal_data_cfg=none p2p_enh=1 fw_name=pcieuart8997_combo_v4.bin +insmod vendor/lib/modules/moal.ko sta_name=wlan uap_name=wlan wfd_name=p2p max_vir_bss=1 cfg80211_wext=0xf cal_data_cfg=none fw_name=sdiouart8987_combo_v0.bin insmod vendor/lib/modules/synaptics_dsx_i2c.ko diff --git a/imx8m/evk_8mq/evk_8mq.mk b/imx8m/evk_8mq/evk_8mq.mk index 7db1b212..210f8971 100644 --- a/imx8m/evk_8mq/evk_8mq.mk +++ b/imx8m/evk_8mq/evk_8mq.mk @@ -250,9 +250,9 @@ PRODUCT_PACKAGES += \ PRODUCT_PACKAGES += \ bt_vendor.conf -# NXP 8997 Wifi and Bluetooth Combo Firmware +# NXP 8987 Wifi and Bluetooth Combo Firmware PRODUCT_COPY_FILES += \ - vendor/nxp/imx-firmware/nxp/FwImage_8997/pcieuart8997_combo_v4.bin:vendor/firmware/pcieuart8997_combo_v4.bin + vendor/nxp/imx-firmware/nxp/FwImage_8987/sdiouart8987_combo_v0.bin:vendor/firmware/sdiouart8987_combo_v0.bin # Wifi regulatory PRODUCT_COPY_FILES += \ The patch is attached as 0001-8mq-usd-8987-wifi.patch evk_8mq enable M.2 8987 wifi            1. hardware rework                hardware rework required ( Be aware: after this rework, uSD is not working!)            2. patches diff --git a/imx8m/evk_8mq/BoardConfig.mk b/imx8m/evk_8mq/BoardConfig.mk index db7c4991..0cca9b8e 100644 --- a/imx8m/evk_8mq/BoardConfig.mk +++ b/imx8m/evk_8mq/BoardConfig.mk @@ -136,7 +136,8 @@ ifeq ($(TARGET_USE_DYNAMIC_PARTITIONS),true) TARGET_BOARD_DTS_CONFIG ?= imx8mq:imx8mq-evk-no-product.dtb else # imx8mq with HDMI display - TARGET_BOARD_DTS_CONFIG ?= imx8mq:imx8mq-evk-pcie1-m2.dtb + TARGET_BOARD_DTS_CONFIG ?= imx8mq:imx8mq-evk-usdhc2-m2.dtb + # imx8mq with MIPI-HDMI display TARGET_BOARD_DTS_CONFIG += imx8mq-mipi:imx8mq-evk-lcdif-adv7535.dtb # imx8mq with HDMI and MIPI-HDMI display diff --git a/imx8m/evk_8mq/SharedBoardConfig.mk b/imx8m/evk_8mq/SharedBoardConfig.mk index 330ab1c5..a6654bad 100644 --- a/imx8m/evk_8mq/SharedBoardConfig.mk +++ b/imx8m/evk_8mq/SharedBoardConfig.mk @@ -7,10 +7,10 @@ PRODUCT_IMX_TRUSTY := true #Enable this to disable product partition build. #IMX_NO_PRODUCT_PARTITION := true -#NXP 8997 wifi driver module +# NXP 8987 wifi driver module BOARD_VENDOR_KERNEL_MODULES += \ - $(KERNEL_OUT)/drivers/net/wireless/marvell/mrvl8997/wlan_src/mlan.ko \ - $(KERNEL_OUT)/drivers/net/wireless/marvell/mrvl8997/wlan_src/pcie8xxx.ko + $(KERNEL_OUT)/drivers/net/wireless/nxp/mxm_wifiex/wlan_src/mlan.ko \ + $(KERNEL_OUT)/drivers/net/wireless/nxp/mxm_wifiex/wlan_src/moal.ko # mipi-panel touch driver module BOARD_VENDOR_KERNEL_MODULES += \ diff --git a/imx8m/evk_8mq/UbootKernelBoardConfig.mk b/imx8m/evk_8mq/UbootKernelBoardConfig.mk index 5aa1ce35..4c3378f0 100644 --- a/imx8m/evk_8mq/UbootKernelBoardConfig.mk +++ b/imx8m/evk_8mq/UbootKernelBoardConfig.mk @@ -14,7 +14,7 @@ endif TARGET_BOOTLOADER_CONFIG += imx8mq-evk-uuu:imx8mq_evk_android_uuu_defconfig TARGET_KERNEL_DEFCONFIG := imx_v8_android_defconfig -# TARGET_KERNEL_ADDITION_DEFCONF ?= android_addition_defconfig +TARGET_KERNEL_ADDITION_DEFCONF ?= android_addition_defconfig # absolute path is used, not the same as relative path used in AOSP make diff --git a/imx8m/evk_8mq/android_addition_defconfig b/imx8m/evk_8mq/android_addition_defconfig new file mode 100644 index 00000000..f51bd5ff --- /dev/null +++ b/imx8m/evk_8mq/android_addition_defconfig @@ -0,0 +1,2 @@ +CONFIG_WLAN_VENDOR_NXP=y +CONFIG_MXMWIFIEX=m diff --git a/imx8m/evk_8mq/early.init.cfg b/imx8m/evk_8mq/early.init.cfg index 9262d953..70097a1c 100644 --- a/imx8m/evk_8mq/early.init.cfg +++ b/imx8m/evk_8mq/early.init.cfg @@ -1,3 +1,3 @@ insmod vendor/lib/modules/mlan.ko -insmod vendor/lib/modules/pcie8xxx.ko sta_name=wlan uap_name=wlan wfd_name=p2p max_vir_bss=1 cfg80211_wext=0xf cal_data_cfg=none p2p_enh=1 fw_name=pcieuart8997_combo_v4.bin +insmod vendor/lib/modules/moal.ko sta_name=wlan uap_name=wlan wfd_name=p2p max_vir_bss=1 cfg80211_wext=0xf cal_data_cfg=none fw_name=sdiouart8987_combo_v0.bin insmod vendor/lib/modules/synaptics_dsx_i2c.ko diff --git a/imx8m/evk_8mq/evk_8mq.mk b/imx8m/evk_8mq/evk_8mq.mk index 7db1b212..210f8971 100644 --- a/imx8m/evk_8mq/evk_8mq.mk +++ b/imx8m/evk_8mq/evk_8mq.mk @@ -250,9 +250,9 @@ PRODUCT_PACKAGES += \ PRODUCT_PACKAGES += \ bt_vendor.conf -# NXP 8997 Wifi and Bluetooth Combo Firmware +# NXP 8987 Wifi and Bluetooth Combo Firmware PRODUCT_COPY_FILES += \ - vendor/nxp/imx-firmware/nxp/FwImage_8997/pcieuart8997_combo_v4.bin:vendor/firmware/pcieuart8997_combo_v4.bin + vendor/nxp/imx-firmware/nxp/FwImage_8987/sdiouart8987_combo_v0.bin:vendor/firmware/sdiouart8987_combo_v0.bin The patch is attached as 0001-8mq-m2-8987-wifi.patch

For IMX8QM and iMX8QXP, the DDR config is in SCFW porting kit with DDR script. After boot, for iMX8QM, the LPDDR4 clock is set to 1.6GHz, and for iMX8QXP, after boot, the LPDDR4 clock is set to 1.2GHz. Their clock source is a HPPLL (High Performance PLL) , the HPPLL work frequency range is 1.25GHz to 2.5GHz. But for some product, due to some EMC signal test requirement, sometimes we need adjust the DDR clock a little, the attached patches can be used as reference to do such test. iMX8QM:    HPPLL = 1600MHz, DRC clock = 800MHz, DDR clock = 1600MHz. iMX8QXP:    HPPLL = 2400MHz, DRC clock = 600MHz, DDR clock = 1200MHz. After applied attached two reference patches in SCFW porting kit, they will be: iMX8QM:    HPPLL = 1584MHz, DRC clock = 792MHz, DDR clock = 1584MHz. iMX8QXP:    HPPLL = 2388MHz, DRC clock = 597MHz, DDR clock = 1194MHz. If you want to try set other clock frequency for iMX8QM, you can change the followed lines: ......  uint32_t rate2 = SC_792MHZ;  /* DRC clock */ ......  DSC_AIRegisterWrite(0x12,0,4,0x00000084);  /* DRC_0: (24M*0x84/2) = 1584M, valid dividder: 0x68~0xD0 */  //This is the HPPLL frequency ......  DSC_AIRegisterWrite(0x28,0,4,0x00000084);  /* DRC_1: (24M*0x84/2) = 1584M, valid dividder: 0x68~0xD0 */  //This is the HPPLL frequency ...... If you want to try set other clock frequency for iMX8QXP, you can change the followed lines: ......  uint32_t rate2 = 597000000U;  /* DRC clock */ ......  DSC_AIRegisterWrite(0x24,0,4,0x000000C7);  /* DRC_0: (24M*0xC7/2) = 2388M, valid dividder: 0x68~0xD0 */  //This is the HPPLL frequency ......

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341566 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341481 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341570 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341641 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341473 

This document describes the i.MX 8MM EVK mini-SAS connectors features on Linux and Android use cases, covering the supported daughter cards, the process to change Device Tree (DTS) files or Boot images, and enable these different display options on the board.

This document describes all the i.MX 8 MIPI-CSI use cases, showing the available cameras and daughter cards supported by the boards, the compatible Device Trees (DTS) files, and how to enable these different camera options on the i.MX 8 boards. Plus, this document describes some Advanced camera use cases too, such as multiples cameras output using imxcompositor_g2d plugin, GStreamer zero-copy pipelines and V4L2 API extra-controls examples.

The iMX8QM LVDS has followed work mode, (There are two LVDS modules in IMX8QM): Single mode (LVDS panel connects to one channel) panel 1 and panel 2 can be different panels: Dual channel split mode (The panel needs two LVDS channels, CH0 for 1,3,5,7,... pixels and CH1 for 2,4,6,8,... pixels): Mirror dual mode (The two panels on same LDB PHY should be same panels on pixel clock and resolution, panel 1 and panel 2 are same; panel 3 and panel 4 are same): The reference patch is based on L5.4.3_GA1.0.0 BSP. LVDS single mode and dual channel split mode are supported in default Linux BSP. Patch 0002 can be used to test this dual mode on MEK board, some rework is needed on MEK board:     R194, R195, R208, R209, R213, R214 should be mounted. And the I6263 board can't be connected to LVDS0_CH0 and LVDS0_CH1 at the same time. The I6263 board can't be connected to LVDS1_CH0 and LVDS1_CH1 at the same time too. Note: for iMX8QXP, there is no mirror dual mode support, because its two LVDS ports are from two different LDB modules, there are no CH1 for them: Note: for iMX8QXP dual channel split mode (The pixel order can be switched: LDB1_CH0 for 1,3,5,7,... pixels and LDB2_CH0 for 2,4,6,8,... pixels; or LDB2_CH0 for 1,3,5,7,... pixels and LDB1_CH0 for 2,4,6,8,... pixels), iMX8QM LVDS has no such feature.

When using Gigabit Ethernet on boards i.MX running Windows 10 IoT Core users may experience network unstability and low latency using build W1809_1_1_0_imx-iotcore. This was fixed by increasing the size of Rx/Tx buffer in ethernet driver. Fix will be part of the next release of BSP, to apply fix to current version a patch was created. To apply patch, copy content of zip archive to appropriate location in folder structure and rebuild BSP.

This document is describe the control method of USB Power based on I.MX6ULL-EVK.   1. Hardware Design USB OTG can be working as device mode, host mode, or switching between both device mode and host mode. (a) USB OTG Device mode When USB OTG is working as device mode, the USB OTG ID pin should be pulled up by a resistor. And the 5V power comes from the VBUS pin of MicroUSB which is the 5V from the external USB HOST. From the above schematic :- When the USB OTG1 ID is pulled to high, the G/S of the NMOSFET Q2SK3018 is turned on. The ENA pin of U1101 is low, and then no 5V output from OUTA. If USB OTG1 is connected to the external USB HOST, a 5V power source will enter the board and supply to the USB OTG1 VBUS pin. (b) Switch between Device and Host mode This is also called USB OTG’s Dual Role. When we plug in MicroUSB with USB TYPE-AB to USB TYPE-A-F cable, USB OTG1 will switch from USB device to Host mode. At this time, the USB OTG1 ID pin will be pulled down to low, the G / S of the NMOSFET will be turned off, the ENA pin of U1101 will be pulled low, and OUTA will output 5V voltage to the VBUS pin of MicroUSB. (c) USB OTG Host mode When USB OTG is working as host mode,  USB OTG1 ID pin connect an external resistor to pull it down or use internal resistor to pull it down. If using external resistor, 2.2K/3.3K ohm resistor is recommended. The USB_OTG1_PWR should output High to enable ENA of U1101, then OUTA will output 5V to USB OTG1 VBUS. On i.MX6ULL-EVK, USB OTG2 port is designed to be Host mode. It can be a design reference. When the USB_OTG2_PWR pulled to high, the U1101 supplies 5V to the outside. 2. Software modification The GPIO1_IO04 can be used to control USB OTG1 power.

Platform: i.MX8QXP/8QM OS: Linux Supported Camera Modules: Max9286 + Max9271 + OV10635, Default BSP Max9286 + Max96705 + AR0144, patch Max9286 + Max96705 + OV9284, patch Max9286 + Max96705 + AP0101 + AR0132, patch NVP6324 + NVP2431 + IMX225, patch TP2855 + TP3812 + IMX307, patch ISL7998x + NTSC/PAL Sensor, patch adv7180 + NTSC/PAL Sensor, patch Detailed description in the attachment.

View the OSS Security and Maintenance Community

         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

Some processor’s GPIO settings on the i.MX Pins Tool version 7 may not show allow to select direction and just show an option “Input/Output” as shown. This will be fixed, but the settings can be changed on the local processor data as a workaround. For more information and documentation for the Pins Tool for i.MX please visit its home page on the link below: https://www.nxp.com/design/designs/pins-tool-for-i-mx-application-processors:PINS-TOOL-IMX   First, find where the Pins Tool data package is stored. To do this open the Pins Tool and click Help > About. On the About screen click the Details button. Take also note of the name of the package that needs to be fixed.   Go to the location where the data package is stored and find the processor data. The file that would need to be updated is signal_configuration.xml    Find the GPIO pin data and change the directions from the string ““inOut”to the string “in out”. Then save this file.    Close and reopen the Pins Tool. The direction on the updated package should now show the options Input and Output.  

SW: Linux 4.14.98_2.2.0 bsp release , gpu sdk 5.3.0 and patch in this doc HW: i.MX8QXP MEK board Inspired by the GIMP adjust color curve tool,  I write similar gui test code for i.MX8QXP gamma curve tuning. That is on display will show one linear curve first, use mouse to change any part of this curve, after that calculate value of point on changed curve , then pass related value to i.MX8QXP DPU gammcor unit , at last the display effect will be changed by DPU. When test code start up , will draw Y=X curve on display, that will from (0,0) to (500, 500) to (1023,1023). After you use mouse drag some part of the curve, will generated a new point (x_new, y_new) which is not on original Y=X curve. Then need draw a new curve that pass  through the (0,0) , (500, 500) , (x_new, y_new), (1023,1023).  That new curve , i choose to use Catmull-Rom Splines to get it. Use Catmull-Rom Splines for approximate a curve that pass through n point, then need n+2 control point. Extra 2 point could be selected as you want ,and they will affect the shape of the curve. Catmull-Rom Splines could pass through all control point, it is C1 continuity, no convex hull property. For example, there is four control point p0, p1 , p2 , p3,  to draw the curve pass through all of them, it could divide to segment p0 to p1 , segment p1 to p2 , segment p2 to p3. For segment p1 to p2 , select four control point as p0,p1, p2, p3, use Catmull-Rom Splines as below: For segment p0 to p1 , need use four control point as p0, p0, p1, p2: For segment p2 to p3, need use four control point as p1, p2, p3, p3: In this test code,  i will use gpu vertex shader to calculate each segment of curve, then use transform feedback to read back point value of each segment to cpu side, cpu side will pass related value to DPU gammcor unit for gamma tuning.   Test steps: Apply 8qxp_dpu_gammacor_4.14.98_2.2.0.diff on linux-imx for i.MX8QXP DPU device driver. Apply dpu_gamma_curve_gpusdk5.3.0.diff on imx-gpu-sdk for build this gui test code. Update the new kernel image, and copy test code to rootfs. Run any other application first to draw some thing on screen, for example  /usr/share/cinematicexperience-1.0/Qt5_CinematicExperience. Then run gui test code in this code, S01_SimpleTriangle_Wayland. Then there will show one linear curve on display , use mouse to change the curve as you like by put mouse cursor close to the curve, press the mouse button , drag it and release the mouse button, you will see the new curve on display , and also the display effect also be changed. Reference: 1>https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-processors/i-mx-8-processors/i-mx-8x-family-arm-cortex-a35-3d-graphics-4k-video-dsp-error-correcting-code-on-ddr:i.MX8X  2>https://www.nxp.com/design/software/embedded-software/linux-software-and-development-tools/embedded-linux-for-i-mx-applications-processors:IMXLINUX?tab=Design_Tools_Tab  3>https://github.com/NXPmicro/gtec-demo-framework  4>https://en.wikipedia.org/wiki/Cubic_Hermite_spline  5>http://www.mvps.org/directx/articles/catmull

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-342059 

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