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i.MX6 Series - Crystal Drive Level guidance; includes calculator.  
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Some customers often use LVDS LCD with low resolution on i.MX6 platform, such as 320x240, but by defualt , linux bsp doesn't support low frequency pixel clock for LVDS module input. Question:     When we port LVDS LCD with 320x240 resolution to android4.2.2, we found pixel clock is not correct, it always output 38.9MHz, it is no probem for big resolution , for example 1024x768, but the clock we need for 320x240 LCD is 6.4MHz.     According to the quesiton, Let us check IPU & LDB clock in i.MX6 datasheet at first : From above table, if ldb clock is from IPU, we will not get 6.4MHz pixel clock, so we will have to adjust its source clock: The following steps are procedure that ports LVDS LCD with 320x240 resolution to i.MX6Q. 1. Adding LVDS LCD timing structure to ldb.c static struct fb_videomode ldb_modedb[] = { {       "LDB-XGA", 60, 320, 240, 155914,       38, 20,       15, 4,       30, 3,       0,       FB_VMODE_NONINTERLACED,       FB_MODE_IS_DETAILED, }, {      "LDB-1080P60", 60, 1920, 1080, 7692,      100, 40,      30, 3,      10, 2,      0,      FB_VMODE_NONINTERLACED,      FB_MODE_IS_DETAILED,}, }; 2.Modifying clock source of ldb module Checking /arch/arm/mach-mx6/clock.c, we can find there are 3 ldb's clock source : &pll5_video_main_clk, &pll2_pfd_352M, &pll2_pfd_400M, static int _clk_ldb_di1_set_parent(struct clk *clk, struct clk *parent) {        u32 reg, mux;        int rev = mx6q_revision();        reg = __raw_readl(MXC_CCM_CS2CDR)               & ~MXC_CCM_CS2CDR_LDB_DI1_CLK_SEL_MASK;        mux = _get_mux6(parent, &pll5_video_main_clk,               &pll2_pfd_352M, &pll2_pfd_400M,               (rev == IMX_CHIP_REVISION_1_0) ?                &pll3_pfd_540M :       /* MX6Q TO1.0 */                &mmdc_ch1_axi_clk[0],     /* MX6Q TO1.1 and MX6DL */               &pll3_usb_otg_main_clk, NULL);        reg |= (mux << MXC_CCM_CS2CDR_LDB_DI1_CLK_SEL_OFFSET);        __raw_writel(reg, MXC_CCM_CS2CDR);        return 0; } By default, pll2_pfd_352M is configured as the clock source of ldb: clk_set_parent(&ldb_di0_clk, &pll2_pfd_352M);        clk_set_parent(&ldb_di1_clk, &pll2_pfd_352M); We should change the clock source to be pll5_video_main_clk clk_set_parent(&ldb_di0_clk, &pll5_video_main_clk,);        clk_set_parent(&ldb_di1_clk, &pll5_video_main_clk,); 3. Configuring initial clock in board-mx6q_sabresd.c static struct ipuv3_fb_platform_data sabresd_fb_data[] = {        { /*fb0*/        .disp_dev = "ldb",        .interface_pix_fmt = IPU_PIX_FMT_RGB666,        .mode_str = "LDB-XGA",        .default_bpp = 16,        .int_clk = false,        .late_init = false, } int_clk=false means LDB clock is from PLL2_PFD_352 or pll5_video_main_clk; int_clk=true mean LDB clock if from IPU. OK, after doing above steps, LVDS LCD with low resolution should normally work. Freescale TICS team Weidong.sun 2015-08-18
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(DEPRECATED. Please check this document for Real Time Streaming) A server can be streaming video and a client, in this case a i.MX6 target, is receiving and decoding it. For example, a server with GStreamer and a web camera connected, can be streaming with the following command: $ # Pipeline 1 $ gst-launch v4l2src ! 'video/x-raw-yuv, format=(fourcc)I420, width=(int)1280, height=(int)800' ! ffenc_mpeg4 ! tcpserversink host=$CLIENT_IP port=$PORT and on the target, the client receives, decodes and display with $ # Pipeline 2 $ gst-launch tcpclientsrc host=$SERVER_IP port=$PORT  ! 'video/mpeg, width=(int)1280, height=(int)800, framerate=(fraction)10/1, mpegversion=(int)4, systemstream=(boolean)false' ! vpudec ! mfw_isink The filter caps between the tcpclientsrc and the decoder (vpudec) depend on the sink caps coming from the server encoder (ffenc_mpeg4), so these may change depending on your needs. Running the above pipelines require the environment variables SERVER_IP, CLIENT_IP and PORT. In case you want the i.MX6 to act as a server, just change the video source (either mfw_v4lsrc of v4l2src) and the encoder (vpuenc), so $ # Pipeline 3 $  gst-launch v4l2src  !  'video/x-raw-yuv, format=(fourcc)I420, width=(int)640, height=(int)480, interlaced=(boolean)false, framerate=(fraction)10/1'  ! vpuenc ! tcpserversink host=$CLIENT_IP port=$PORT For testing purposes, set SERVER_IP=127.0.0.1, CLIENT_IP=127.0.0.1 and PORT=500, and run pipeline 3 and 2 in two different consoles. Check with 'top' the  CPU usage and see that VPU is actually doing most of the work.
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I've done some research in Android boot optimization in the past months and have some getting. This page is for recording and sharing purpose only. It's target to provide some hints and directions for Android optimization. It's NOT a Freescale official document or patch release. The code/doc inside is only for reference. Background:      1. I've used SabreSD + Android KK 4.4.2 GA 1.0 as a reference platform.      2. I'm not doing some popular optimization way such as "hibernation", "suspend". I'm trying to "optimize" the boot process by re-arranging the boot process and make GUI related process run earlier and fine tune some boot code for running faster.      3. It's target to the Android IVI product. So, some features that will never be used in a IVI environment will be disabled or removed. Minor of them. I've come out with a patch package (latest is milestone 4 which is "_m4" in the version for short) and  a training document. I didn't find any confidential information from the patch or doc, so I'm open the sharing here. Updated on 2016/01/08 for new version (milestone m5): --------------------------------------------------------------------------------------- Change log against previous (milestone 4) version:      1. BSP base changed to Android KK 4.4.3 GA 2.0 which has a Linux kernel 3.10.53      2. Linux kernel and uboot optimization added. Kernel boot time (POR -> Android init entry) is less than 1.5s.      3. Some bug fixes.      4. Document updated accordingly. Total boot time tested on SabreSDP is about 8s.
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When working with IPU applications, sometimes image format converter is needed to check images generated by IPU that are not readable by PC (e.g. RGB565, common i.MX framebuffer format -> png or jpg) or generate a RGB picture from an encoded file to be read by IPU (e.g. png -> RGB565 framebuffer). There are some useful tools on Linux and some also available on Windows that can perform these conversions. I listed 5 tools with some usage examples below. IMAGEMAGICK // Display a 800x600 rgb image display -size 800x600 -depth 8 rgb:output.rgb // Show information of output.rgb identify -size 1296x972 -depth 8 output.rgb // Convert a 640x480 grayscale raw rgb file to png convert -size 640x480 -depth 8 imagefile.rgb image.png // To list all available color formats identify -list format For more information about Imagemagick and its format support. access: http://www.imagemagick.org/script/formats.php FFMPEG // List available formats for ffmpeg ffmpeg -pix_fmts // Convert raw rgb565 image to png ffmpeg -vcodec rawvideo -f rawvideo -pix_fmt rgb565 -s 1024x768 -i freescale_1024x768.raw -f image2 -vcodec png screen.png // Convert png to raw rgb565 ffmpeg -vcodec png -i image.png -vcodec rawvideo -f rawvideo -pix_fmt rgb565 image.raw // Convert a 720x480 NV12 (YUV 420 semi-planar) image to png ffmpeg -s 720x480 -pix_fmt nv12 -i image-nv12.yuv -f image2 -pix_fmt rgb24 image-png.png // Convert a 640x480 uyvy422 image to png ffmpeg -s 640x480 -pix_fmt uyvy422 -i image-uyvy422.yuv -f image2 -pix_fmt rgb24 image-uyvy422.png MENCODER http://www.mplayerhq.hu/DOCS/HTML/en/encoding-guide.html TRANSCODING http://www.transcoding.org/cgi-bin/transcode?Examples GRAPHICSMAGICK http://www.graphicsmagick.org/
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In recovery mode, recovery may update /boot or /system, but it never overwrite itself. The update of /recovery is in the normal bootup. When system boot up, it will execute init.rc which will call install-recovery.sh. The install-recovery.sh is in update.zip. when the system is in recovery mode, updater-script will  unzip update.zip, and the install-recovery.sh will be unzip into /system/etc/. So if you update your image through recovery mode, the install-recovery.sh will be unzip to /system/etc/ automatically. If your update.zip do not include install-recovery.sh. You can edit it and copy it to /system/etc. the below is content in install-recovery.sh. #!/system/bin/sh if ! applypatch -c EMMC:/dev/block/mmcblk3p2:7762488:374c3807940a38d9497a4c5ef64a069e553bc218; then   log -t recovery "Installing new recovery image"   applypatch -b EMMC:/dev/block/mmcblk3p1:7203059:238a297e7e3c7197b2f5af646d0e7e49cef0fd9f EMMC:/dev/block/mmcblk3p2  374c3807940a38d9497a4c5ef64a069e553bc218 7762488 c3c9482c8616805ea4c071ee9184240936f260e5:/system/recovery-from-boot.p else   log -t recovery "Recovery image already installed" fi Explain of the install-recovery.sh: 1、 judge whether the recovery-imx6q.img’s sha1 is the same with mmcblk3p2 on board. 374c3807940a38d9497a4c5ef64a069e553bc218 is the new recovery-imx6q.img’s sha1. 7762488 is the length of recovery-imx6q.img. 2、 if not the same , that mean it was a new recovery-imx6q.img. make a new recovery-imx6q.img through patch recovery-from-boot.p on boot.img. 7203059 and 238a297e7e3c7197b2f5af646d0e7e49cef0fd9f is the length and sha1 of boot.img.     src-file EMMC:/dev/block/mmcblk3p2 is the recovery partition.      tgt-file c3c9482c8616805ea4c071ee9184240936f260e5 is the sha1 of recovery-from-boot.p which is in update.zip. Note: 1、 recovery-from-boot.p is in update.zip. And it is unzip into /system. It is the patch of boot-imx6q.img and recovery-imx6q.img. 2、 for EMMC:/dev/block/mmcblk3p2 is the partition, you can check ./out/target/product/sabresd_6dq/recovery/root/etc/recovery.fstab to see detail partition. Check whether recovery is updated, there are two ways to check: 1、 you can write printf() in file bootable/recovery/recovery.cpp. On the board you can check the file /cache/recovery/last_log. You can find what you printf if the recovery.img was updated. 2、 Also you can use the adb the pull the recovery file system to check whether the recovery was updated.
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i.MX6X_3.14.28_内核驱动代码与定制_devicetree_V1-20150918.doc
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Descriptions on the issue: running “uuu uuu-android-mx8mq-evk-emmc.lst” No any problem, downloading images is OK. running “uuu_imx_android_flash.bat -f imx8mq -a -e” Below lines will be showed on windows console: flash the file of u-boot-imx8mq.imx to the partition of bootloader0 <waiting for any devices>             Then downloading operation stopped. ------------------------------------------------------------------------                 In order to help uses save development time, I tested above 2 commands for downloading images on windows 7 64bit and windows 10 64bit respectively.                 Below is detailed steps for the operation: Hardware Preparations (1) Switch SW802 on i.MX8MQ EMEK, set 1-4 off, 2-3 on i.MX8MQ is at usb serial download mode. (2) Connecting J1701 to PC USB by a USB OTG cable. (3) Connecting J901(usb type c) to PC USB by a USB 3.0 cable. (4) Plugging 12V@3.5A adapter into Power Jack (J902) (5) Power on I.MX8MQ board via SW701 Switch Software Preparations (1) Related windows drivers for i.MX8MQ MEK                 Windows 7 64bit or windows 10 64bit will find new devices and begin to search and install corresponding drivers, like below:                 Probably windows 10 64bit can’t automatically install CP2105 driver from official website of manufacture: https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers                 Then installed it manually. (2) Power off i.MX8MQ MEK (3) Installing winusb driver by zadig                 According to method described in uuu.pdf, download zadig tool from https://zadig.akeo.ie/, and install it to windows 7 64bit . [Note] windows 10 64bit doesn’t need to install winusb driver. Press “Install WCID Driver” Button (4) Downloading Android SDK Manager Download SDK Manager from : http://visualgdb.com/android/install_redir?item=SDK After downloading it, decompress it, and run SDK Manager application: Press OK. Then press “Close” Close SDK Manager Installation Guide . Find the directory of SDK Manager installation, and enter into “platform-tools”, like below: D:\i.MX8-Projects\IMX8MQ-MEK-windows-drivers\android-sdk_r24.4.1-windows\android-sdk-windows\platform-tools Copy items in blue rectangle to C:\windows\system Copy items in red rectangle to C:\windows\system32     Beginning to download android images to I.MX8MQ MEK via UUU Tool (1) Downloading android DEMO images for i.MX8MQ MEK https://www.nxp.com/support/developer-resources/software-development-tools/i.mx-developer-resources/evaluation-kit-for-the-i.mx-8m-applications-processor:MCIMX8M-EVK?tab=Design_Tools_Tab After downloading it, decompress it to a directory.  Like below: (2) Downloading UUU Tool https://github.com/NXPmicro/mfgtools/releases After downloading uuu.exe,  copy it to the directory of android 9.0 demo image , see above. (3) Run command “uuu_imx_android_flash.bat -f imx8mq -a -e” ----Power on i.MX8MQ MEK. ----open a command line window ---open Hyper terminal ( set it 115200 bps) ---run “uuu_imx_android_flash.bat -f imx8mq -a -e”           For windows 10 64bit, downloading images will be done without any errors.    But for windows 7 64bit, downloading images will stop at “ waiting for any devices”.    It means Android ADB driver will be needed. Follow the steps below to solve the problem. Right button, click “update driver” Close it.           Then downloading operations will be automatically continued. OK, done. NXP TIC team Weidong Sun 02-25-2019
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With Qt5  you will find the addition of new technologies that will make your development much easier. Qtquick2 SceneGraph Qml Qt5 is backwards compatible,  that means you can run your Qt 4.8 applications, But that doesn't mean they will have the best performance, sometimes it is better to do a porting to use the newest features. Qt5, has two options to paint components into the screen. Painting in Qt 5 is primarily done either with: The imperative QPainter API Qt’s declarative UI language, QML, and its scene graph back-end. QPainter As this document mentions  Qt5GraphicsOverview | Qt Wiki | Qt Project  The Qpainter engine uses software to paint, and is used when drawing Qimages or Qwidgets. Its  advantage over OpenGL is the high quality when antialiasing is enabled, and a complete feature set. The Qpainter can use an OpenGL engine, but as the document mentions it is more suceptible to state changes. And has to be used carefully. QML & Scene Graph. All visual QML items are rendered using the scene graph, a low-level, high-performance rendering stack, closely tied to OpenGL. Qt Quick 2 makes use of a dedicated scene graph based on OpenGL ES 2.0 or OpenGL 2.0 for its rendering. Using a scene graph for graphics rather than the traditional imperative painting systems (QPainter and similar), means the scene to be rendered can be retained between frames and the complete set of primitives to render is known before rendering starts. This opens up for a number of optimizations, such as batch rendering to minimize state changes and discarding obscured primitives. The QML scene graph is a new back-end for QML in Qt 5, and is based on OpenGL. It generally improves the performance of QML significantly over the QPainter-based back-end used in Qt 4. It achieves better performance in a number of ways: The scene graph uses OpenGL directly instead of going though a QPainter which could be using either the raster or OpenGL paint engine. This means that all the resources, like geometry, textures and shaders can be stored in a format suitable for OpenGL rather than using classes such as QPainterPath, QPixmap, QBrush, or QPen, which the QPainter would need to translate into OpenGL primitives and possibly cache. QML, being a declarative language, defines how the end result should look like, but it doesn’t define how and in which order each individual element is drawn. The drawing can therefore be reordered to reduce the number of state changes, or merged to reduce the number of draw calls. The scene graph uses a separate render thread, and synchronizes the animations with the vertical retrace on platforms where this can be supported. The render thread allows the preparation of the next frame to be done at the same time the current frame is being rendered. This has a positive effect also on single-core systems, since the render thread might block on OpenGL commands. The synchronization with the vertical retrace improves the perceived smoothness of the animations. We have tested on i.MX6 Both options, having the best results using QML Qtquick2 elements. When we tried using QtPainter via Widgets we face the problem that if not using a windowing system like X11 or Wayland the painter wont work well and will only show the QtGLWidget. With QML scene graph we are able to have an OpenGL element and a Qt element on the same environment, and there is an easy way to communicate one with the other and share variables.  Please look at the example results here: I.MX6 scene graph Qt5 - YouTube And the great advantage, the sceneGraph is all accelerated via OpenGL.
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本文已经发表于中国集成电路杂志2014年第七期 For English version, please check following link. Freescale i.MX6 DRAM Port Application Guide-DDR3
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When working on the IOMUX settings of an i.MX processor for our design it’s always good to make use of the IOMUX Tool provided by Freescale on the Download Page of most i.MX processors. We’ll focus on the latest release of the IOMUX tool for i.MX6. The IOMUX tool provides a Graphic User Interface to easily assign internal signals to external pins/balls and resolve any potential pin conflict and muxing options for the different modules available on the i.MX processors. IOMUX Tool Download (Will request to log in) Freescale’s Boards IOMUX settings. On the IOMUX tool package you’ll find the User’s Manual and also a folder containing the muxing options for Freescale’s Reference Boards, which may be of help when working with the Reference Designs as a starting point. You may load these settings files using the file/open option. MMDC pins Since the Multi-mode DDR controller MMDC pins are not muxed these cannot be changed on the IOMUX tool. This because the memory interfaces are much more sensitive to interference and thus have dedicated pins that do not share pad with other signals. The registers are also set on the default value so it’s good to keep this in mind when working with the code provided by the IOMUX tool. Considerations when using generated code The tool can generate code to be used as reference of the IOMUX configuration but still requires manual tweaking and the header files available on the i.MX Processor’s BSP in order to be implemented in an actual application code. It’s important to review the register settings on the Register tab in order to export the desired values; otherwise the code will have the default values for the registers according to the IOMUX tool. This is especially true for the Daisy Chain settings, always manually review these. Import function limitations There is an import function available so IOMUX configuration files saved in previous versions of the IOMUX tool can be loaded on the newest version. However, this feature should be used carefully. When importing a design it’s recommended to save the imported design on the new version of the IOMUX tool as imported.xml; then opening a new configuration and saving it as new.xml and comparing register value differences to manually correct the imported.xml values. In small projects it might be recommended to manually load the IOMUX information on the new IOMUX tool version to avoid register conflicts from version to version. For more information please refer to the documentation available within the IOMUX tool package. An advanced example is also included in that document.
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         This document will describe how to add open JDK to i.MX yocto BSP. It will take two versions of Linux BSP as an example, one is the lower version of L4.1.15-2.0.0, the other is the latest version of L4.19.35-1.1.0. Adding openjdk-8 to L4.1.15-2.0.0(Ubuntu 16.04 LTS platform) Before adding an open JDK, you must download L4.1.15-2.0.0 BSP according to the i.MX_Yocto_Project_User's_Guide.pdf, and ensure that it can pass the compilation normally, that is to say, there is no error in the compilation. In this example, BSP is compiled using the following command. # DISTRO=fsl-imx-wayland MACHINE=imx6sxsabresd source fsl-setup-release.sh -b build-wayland # bitbake fsl-image-qt5          Then follow the steps below to add openjdk to the yocto layer:   Fetching openjdk-8 from Yocto website # cd ~/imx-release-bsp # cd sources # git clone git://git.yoctoproject.org/meta-java # cd meta-java # git checkout -b krogoth origin/krogoth  [Comment]    Yocto’s version is described in i.MX_Yocto_Project_User's_Guide.pdf 2. Modifying related configurations (1) build-wayland/conf/local.conf Add following lines to the file: # Possible provider: cacao-initial-native and jamvm-initial-native PREFERRED_PROVIDER_virtual/java-initial-native = "cacao-initial-native" # Possible provider: cacao-native and jamvm-native PREFERRED_PROVIDER_virtual/java-native = "cacao-native" # Optional since there is only one provider for now PREFERRED_PROVIDER_virtual/javac-native = "ecj-bootstrap-native" IMAGE_INSTALL_append = " openjdk-8" Save it and exit (2)build-wayland/conf/bblayers.conf Add java layer to the file, like below: BBLAYERS = " \   ${BSPDIR}/sources/poky/meta \   ${BSPDIR}/sources/poky/meta-poky \   \   ${BSPDIR}/sources/meta-openembedded/meta-oe \   ${BSPDIR}/sources/meta-openembedded/meta-multimedia \   \   ${BSPDIR}/sources/meta-fsl-arm \   ${BSPDIR}/sources/meta-fsl-arm-extra \   ${BSPDIR}/sources/meta-fsl-demos \   ${BSPDIR}/sources/meta-java \ "…… Save it and exit. 3. Build openjdk-8 # cd ~/imx-release-bsp # source setup-environment build-wayland #bitbake openjdk-8 -c fetchall          Fetch all packages related to openjdk-8. [error handling]          During downloading packages, you may encounter errors like the following. (1)Fetch fastjar-0.98.tar.gz errors          The error is caused by invalid web address, we can download it from another link, see below: http://savannah.c3sl.ufpr.br/fastjar/fastjar-0.98.tar.gz copy the link to firefox in Ubuntu platform, and it will be downloaded into ~/Downloads # cd ~/imx-release-bsp/downloads # cp ~/Downloads/ fastjar-0.98.tar.gz ./ # touch fastjar-0.98.tar.gz.done   (2)Fetch “classpath-0.93.tar.gz” error          Download it from : http://mirror.nbtelecom.com.br/gnu/classpath/classpath-0.93.tar.gz And copy it to ~/imx-release-bsp/downloads, and create a file named classpath-0.93.tar.gz.done in the directory. # cd ~/imx-release-bsp/downloads # cp ~/Downloads/ classpath-0.93.tar.gz ./ # touch classpath-0.93.tar.gz.done (3) 8 files with tar.bz2 (hotspot-Java jvm)          These similar errors are very likely to be encountered.          These errors are caused by the bad network environment. You can download these packages manually. These are Java virtual machine source packages, i.e. hotspot JVM [Solution] # mkdir ~/temp # cd temp # wget http://www.multitech.net/mlinux/sources/56b133772ec1.tar.bz2 # wget http://www.multitech.net/mlinux/sources/ac29c9c1193a.tar.bz2 # wget http://www.multitech.net/mlinux/sources/1f032000ff4b.tar.bz2 # wget http://www.multitech.net/mlinux/sources/81f2d81a48d7.tar.bz2 # wget http://www.multitech.net/mlinux/sources/0549bf2f507d.tar.bz2 # wget http://www.multitech.net/mlinux/sources/0948e61a3722.tar.bz2 # wget http://www.multitech.net/mlinux/sources/48c99b423839.tar.bz2 # wget http://www.multitech.net/mlinux/sources/bf0932d3e0f8.tar.bz2          Then create .tar.bz2.done files for each package via touch command   # touch 56b133772ec1.tar.bz2.done # touch ac29c9c1193a.tar.bz2.done # touch 1f032000ff4b.tar.bz2.done # touch 81f2d81a48d7.tar.bz2.done # touch 0549bf2f507d.tar.bz2.done # touch 0948e61a3722.tar.bz2.done # touch 48c99b423839.tar.bz2.done # touch bf0932d3e0f8.tar.bz2.done          Like below:          Then copy these files to ~/ fsl-release-bsp/downloads/ # bitbake openjdk-8 -c compile          After openjdk compilation, you will be prompted as follows:          At last , install openjdk-8 to images # bitbake fsl-image-qt5          Done: [Additional description]          The above method of adding openjdk-8 is the steps after BSP compilation. Users can also add openjdk-8 before BSP compilation, and then compile it with BSP          According to steps in i.MX_Yocto_Project_User's_Guide.pdf, After running the following two commands, users can modify bblayers.conf and local.conf directly.          For example, steps below have been validated: … … # repo sync # cd ~/fsl-release-bsp # DISTRO=fsl-imx-x11 MACHINE=imx6qsabresd source fsl-setup-release.sh -b build-x11 # gedit ./conf/bblayers.conf          Add the same contents as above. # gedit ./conf/local.conf          Add the same contents as above. # bitbake fsl-image-gui          During compilation, users may encounter some errors, which can be handled by referring to the methods described above Adding openjdk-8 to L4.19.35-1.1.0(Ubuntu 18.04 LTS Platform) In fact, the steps to add openjdk-8 to l4.19.35 are the same as those described above, and the following steps have been verified. Before adding openjdk-8, i.mx8qxp full image has been compiled with 2 commands below, so we only need to add openjdk-8 here. # DISTRO=fsl-imx-xwayland MACHINE=imx8qxpmek source fsl-setup-release.sh -b build-xwayland # bitbake imx-image-full # cd sources # git clone git://git.yoctoproject.org/meta-java # cd meta-java # git checkout -b warrior origin/warrior          Release L4.19.35_1.1.0 is released for Yocto Project 2.7 (Warrior). # cd ~/imx-release-bsp-l4.19.35 # source setup-environment build-xwayland-imx8qxpmek # gedit ./conf/bblayers.conf          Add meta-java to it.          ……            ${BSPDIR}/sources/meta-java \          ……          Save and exit. # gedit ./conf/local.conf          Add these lines to it.          # Possible provider: cacao-initial-native and jamvm-initial-native PREFERRED_PROVIDER_virtual/java-initial-native = "cacao-initial-native" # Possible provider: cacao-native and jamvm-native PREFERRED_PROVIDER_virtual/java-native = "cacao-native" # Optional since there is only one provider for now PREFERRED_PROVIDER_virtual/javac-native = "ecj-bootstrap-native" IMAGE_INSTALL_append = " openjdk-8" Save and exit.   # cd ~/imx-release-bsp-l4.19.35/build-xwayland-imx8qxpmek # bitbake openjdk-8 -c fetch # bitbake openjdk-8 -c compile [Errors] [Solution] # gedit ./ tmp/work/x86_64-linux/openjdk-8-native/172b11-r0/jdk8u-33d274a7dda0/hotspot/make/linux/Makefile Comment the following lines: ----------------------------------------- check_os_version: #ifeq ($(DISABLE_HOTSPOT_OS_VERSION_CHECK)$(EMPTY_IF_NOT_SUPPORTED),) #       $(QUIETLY) >&2 echo "*** This OS is not supported:" `uname -a`; exit 1; #endif -----------------------------------------          Then continue # cd ~/imx-release-bsp-l4.19.35/build-xwayland-imx8qxpmek # bitbake openjdk-8 -c compile [comment]          Probably similar errors will be encountered during compiling other packages, we can use the same way like above to solve it, see bellow, please! Done:          At last, install openjdk-8 to images. # bitbake imx-image-full          Installation is done. NXP TIC Team  Weidong Sun 12/31/2019
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The attached patch enables HDMI overscan for Android JB, and tested by MX6Q SabreSD with Android_4.2.2_1.0.0-ga. The bootargs includes "video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off".
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NOTES: Empty cells do not mean there is no bitbake parameter for the corresponding ltib one. This is still work in progress. Both engines are completely different and doing a one-to-one comparison is not actually fair. The following tables compare the two core build tools, ltib for LTIB and bitbake for the Yocto Project (YP, hereafter). For YP, there is another important tool called HOB,  when appropriate, we add comments on the Comment's column. There are two main tables, 'ltib modes versus bitbake' 'ltib options versus bitbake'.          We split in two based how ltib splits its parameter, so the order is the same as the one shown when typing './ltib --help'. LTIB comes in every released BSP, follow the User Guide to install it. The command 'ltib' is a script located on the folder with the same name, so all ltib commands should be run with './' as prefix YP can be seen of a series of layers (folders). To download these, including the Freescale layers, follow this link. The command 'bitbake' must be installed independently, you can either use the package manager of you OS (e.g. sudo apt-get install bitbake on Ubuntu) or download the source code and do the setup manually. Both ways should place the bitbake script into a executable path. ltib modes versus bitbake Mode description ltib command bitbake command Comment Just prep the package ltib -m prep -p <package> bitbake <package> -c patch With bitbake when running the patch task, it executes two lower tasks: fetch and unpack. For example, if one wants a untouched (no yocto patches) kernel, one can try: 'bitbake linux-imx -c unpack' and code unpacked code is placed on tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/<version>/git/ rpmbuild -bc --short-circuit ltib -m scbuild -p <package> bitbake <package> -c compile With bitbake running compile also runs a lower task: configure. rpmbuild -bi --short-circuit ltib -m scinstall -p <package> bitbake <package> -c With ltib the install task executes the %Install section of the package's spec. With bitbake the same task executes all related package's recipe install functions, e.g. do_install. Note: with ltib running a higher task (like scinstall) will not execute lower tasks (like scbuild and prep); this is not the case for bitbake: it runs lower tasks automatically. does an scinstall followed by an install to the rootfs ltib -m scdeploy -p <package> bitbake <package> -c build With bitbake, build is the default task, so one can even omit the -c build parameter, e.g. 'bitbake <package>' generate and merge a patch (requires -p <pkg>) ltib -m patchmerge -p <package> NA This is a pretty nice feature from LTIB, unfortunately with bitbake the command does not exit. For example, to patch the Kernel's recipe, take a look at this procedure. In case you follow all these steps to fix a bug, do not forget to send your patch to the community. lean/uninstall target packages ltib -m clean -p <package> NA With bitbake the 'clean' counterpart does not exit. If one needs to remove a specific package from a build, you may remove it from the image configuration file (e.g. file meta-fsl-demos/recipes-fsl/images/fsl-image-gui.bb, remove item on IMAGE_INSTALL variable); if package is inside a package group (e.g. ./meta-fsl-demos/recipes-fsl/packagegroup/packagegroup-fsl.bb) you may remove it there. After this change, bitbake again and the resulting image won't have the package. With HOB, this is much simpler due to its Graphical User Interface. Just type hob on your build directory, select the machine and the base image, then click on the 'Edit Image'. On that window you can easily deselect packages. Once deselection is done, build the image. full cleanup, removes nearly everything ltib -m distclean NA With bitbake the 'distclean' command does not exit. The way to remove all the built, remove the build/tmp folder. Be careful, next time you run bitbake, all tasks for all packages will be executed, in other words, you will start from scratch. list packages (alphanumeric) ltib -m listpkgs non-GUI: bitbake -g fsl-image-gui && cat pn-depends.dot GUI: bitbake -g -u depexp fsl-image-gui A bit more complex non-GUI: bitbake -g <image> && cat pn-depends.dot | grep -v -e '-native' | grep -v digraph | grep -v -e '-image' | awk '{print $1}' | sort | uniq list package names and licenses ltib -m listpkgseula NA With HOB, you can see every package name name and its licence. Just type hob, then select the machine and image, and click on the 'Edit Image' button. On the 'All recipes' tab, you get a list of packages with their licenses. list packages in twiki format ltib -m listpkgstw NA list packages in a format for import into spreadsheet ltib -m listpkgscsv NA make a binary release iso image ltib -m release NA make a non-distributable test iso release ltib -m trelease NA configure selected platform (no build) ltib -m config NA There is no way to open a configuration menu with bitbake. Instead, you can use hob. With hob, things are much easier. Just type hob under the build folder and you can select the machine and the image. If the image you want does not fit to the ones already available, you can add packages manually and even store your new tuned image. NOTES: 1. On YP, an image is a similar concept as LTIB's package profile (usually called just profile). There are many predefined images which can be used as starting point, so type 'bitbake <image name>'. 2. In case the kernel needs to be configure, run 'bitbake linux-imx -c menuconfig'. sub-platform selection (no build) ltib -m selectype NA The selectype on LTIB opens two menus: 1. Platform and the Package Profile selection 2. Configuration menu (the same menu as the one shown with -m config). In case one needs to do execute just the first task, just run 'bitbake <image name>'. In case you need to execute both, run hob. enter ltib shell mode (sets up spoofing etc) ltib -m shell bitbake <package name> -c devshell import srpms into ltib (semi-automatic) ltib -m addsrpms ltib options versus bitbake Option Description ltib command bitbake command Comments Root context number (0 is the primary and implicit) ltib --rootn | ltib -R operate on this package only ltib --pkg | ltib -p bitbake <package> With bitbake there is no need to add a '-' parameter, just use the package name without the .bb extension run the interactive configuration and build ltib --configure  | ltib -c NA See the mode -m config for more info run the sub-platform configuration and build ltib --selectype NA See the mode -m selectype for more info configuration file to build from (defaults to .config) ltib --preconfig bitbake <predefined image> With bitbake use any of the predefined images (assuming that these have not been modified), e.g. bitbake core-image-minimal or bitbake fsl-image-gui (it happens to be the smallest and the largest image, in terms of number of packages) profile file.  This is used to select an alternate  set of userspace packages, this is saved and used on later runs of ltib (e.g config/profiles/max.config) ltib --profile use this resource file ltib --rcfile <f> | ltib - r <f> batch mode, assume yes to all questions ltib --batch | ltib -b force rebuilds even if they are up to date ltib --force | ltib -f bitbake --force | bitbake -f For example, to force recompiling the kernel: bitbake linux-imx -c compile -f re-install rpms (but don't force rebuild) ltib --reinstall | ltib -e bitbake <package name> -c install -f remove (erase) rpm ltib --erase | ltib -E turn off install/uninstall dependency checks ltib --nodeps | ltib -n bitbake -b <somepath/somefile.bb> For example, to build just the kernel (no dependencies, just kernel): bitbake -b ../sources/meta-fsl-arm/recipes-kernel/linux/linux-imx_3.0.35.bb NOTE: ALL dependencies should be already be installed, otherwise the command will fail don't force install rpms that have file conflicts ltib --conflicts | ltib -k keep the srpms after the build (deleted by default) ltib --keepsrpms | ltib -s more output ltib --verbose | ltib -v bitbake --verbose | bitbake -v On YP, the log can be too verbose, so one way to handle the amount of log is to store it and then grep it: bitbake linux-imx | tee log; grep -i <your string to seach> < log mostly a dry run (calls to system are just echos) ltib --dry-run | ltib -d bitbake --dry-run | bitbake -n try to continue on package build errors (autobuilds) ltib --continue | ltib -C bitbake --continue | bitbake -k print the application version and quit ltib --version | ltib -V bitbake --version do not redirect any output ltib --noredir | ltib -N run the deploy scripts even if build is up to date ltib --deploy | ltib -D bitbake <image name> -f disabled deployment (even with -p <pkg>) ltib --no-deploy just download the packages only ltib --dlonly bitbake -c fetchall <image name> E.g. bitbake -c fetchall core-image-minimal test that the BSP's packages are available ltib --dltest check against external staging repositories ltib --external leave the sources unpacked (only valid for pkg mode) ltib --leavesrc | ltib -l NA This is the default mode in YP. All source code can be found on tmp/work. In case you want to remove source code after building (as in LTIB), add INHERIT += "rm_work" to your local.conf. NOTE: If your adding changes to a particular package, these will be lost. In case you want to keep source code of a specific package, include this on the RM_WORK_EXCLUDE variable (e.g. RM_WORK_EXCLUDE += "busybox eglibc"). Make the selected root number sticky --sticky Remove root stickiness --no-sticky (re)configure/build/install the host support package set --hostcf use with package listings --enable use if you really want to ignore any locks (careful!) --ignorelock used with -m release to copy additional content --fullbsp used with -m release to copy specical packages into ISO --distmap don't check sudo, work around for broken sudo (fc9) --no-sudo use git for some package's build where use-git-mode is either: internal    Use fsl internal git external   Use fsl external git --use-git-mode use external git for some package's build --external-git help on usage --help | -h --help | -h
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The i.MX Android O8.0.0_1.0.0 GA release is now available from IMX_SW page. Overview -> BSP Updates and Releases -> Android 8.0.0 Oreo (O8.0.0_1.0.0, 4.9 kernel)   Files available: # Name Description 1 android_O8.0.0_1.0.0_docs.tar.gz i.MX Android O8.0.0_1.0.0 BSP Documentation 2 imx-o8.0.0_1.0.0_ga.tar.gz i.MX Android O8.0.0_1.0.0 proprietary surce code for i.MX 6QuadPlus, i.MX 6Quad, i.MX 6DualPlus, i.MX 6Dual, i.MX 6DualLite, i.MX 6Solo  i.MX 6Sololite, i.MX6SX and i.MX7D 3 android_O8.0.0_1.0.0_image_6dqpsabreauto.tar.gz Binary Demo Files of Android O8.0.0_1.0.0 BSP - SABRE for Automotive Infotainment based on i.MX 6QuadPlus, i.MX 6Quad, and i.MX 6DualLite 4 android_O8.0.0_1.0.0_image_6dqpsabresd.tar.gz Binary Demo Files of Android O8.0.0_1.0.0 BSP - SABRE Platform and SABRE Board based on i.MX 6QuadPlus, i.MX 6Quad and i.MX 6DualLite. 5 android_O8.0.0_1.0.0_image_6slevk.tar.gz Binary Demo Files of Android O8.0.0_1.0.0 BSP - i.MX 6Sololite evaluation kit. 6 android_O8.0.0_1.0.0_image_6sxsabresd.tar.gz Binary Demo Files of Android O8.0.0_1.0.0 BSP - SABRE Board based on i.MX 6SoloX 7 android_O8.0.0_1.0.0_image_6sxsabreauto.tar.gz Binary Demo Files of Android O8.0.0_1.0.0 BSP - SABRE for Automotive infotainment based on i.MX 6SoloX 8 android_O8.0.0_1.0.0_image_7dsabresd.tar.gz Binary Demo Files of Android O8.0.0_1.0.0 BSP - SABRE Board based on i.MX 7Dual 9 fsl_aacp_dec_O8.0.0_1.0.0.tar.gz AAC Plus Codec for O8.0.0_1.0.0 10 android_O8.0.0_1.0.0_tools.tar.gz Manufacturing Toolkit and VivanteVTK for O8.0.0_1.0.0   Supported Hardware SoC/Boards: i.MX 6Quad, i.MX 6QuadPlus, and i.MX 6DualLite SABRE-SD board and platform i.MX 6Quad, i.MX 6QuadPlus, and i.MX 6DualLite SABRE-AI board and platform i.MX 6SoloLite EVK platform i.MX 6SoloX SABRE-SD board and platforms i.MX 6SoloX SABRE-AI board and platforms i.MX 7Dual SABRE-SD board and platform   Changes: Compared to the N7.1.2_2.0.0 release, this release has the following major changes: Upgraded the Android code base from android-7.1.2_r9 to android-8.0.0_r25. Removed the device partition and added the vendor partition. Enabled ION-based gralloc and EGL. Feature: For features please consult the release notes.   Known issues For known issues and more details please consult the Release Notes.
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According to EHSET_v1.01.pdf description (http://testusb.com/EHHS.html), the USB physical certification test are from 2 sides. One test case is PC running USB-IF HSET utility as being USB host to test the target board being USB device; the other case is target board acting as USB host to initate test signals to a test fixture. The principle of test modes supported are based on Vid/Pid pair  during enumration by host whoever takes. Apply the attached patch (I use r13.4.1 kernel_imx tree), then enable "FSL_USB_TEST_MODE" in kernel config, rebuild uImage to get the test modes support kernel.
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Platform: imx8qm mek imx-yocto-L4.14.98_2.0.0_ga Building Step: Apply the nvp6324 patches.   Symbol: IMX8_NVP6324 [=y] Type : tristate Prompt: IMX8 NVP6324 Driver Location: -> Device Drivers -> Multimedia support (MEDIA_SUPPORT [=y]) -> V4L platform devices (V4L_PLATFORM_DRIVERS [=y]) -> MX8 Video For Linux Video Capture (VIDEO_MX8_CAPTURE [=y]) (1) -> IMX8 Camera ISI/MIPI Features support ‍‍‍‍‍‍‍‍‍ select nvp6324 to y in menuconfig(default is 'y') make Image -j8; make freescale/fsl-imx8qm-mek-nvp6324.dtb, to build kernel and dts, outputs are at  work/imx8qmmek-poky-linux/linux-imx/4.14.98-r0/build/arch/arm64/Image work/imx8qmmek-poky-linux/linux-imx/4.14.98-r0/build/arch/arm64/boot/dts/freescale/fsl-imx8qm-mek-nvp6324.dtb copy them to the sd boot partition. reboot the board, you can test the first camera with command: ./mx8_v4l2_cap_drm.out -cam 1 -ow 1280 -oh 720 mx8_v4l2_cap_drm.out is at /unit_tests/V4L2/mx8_v4l2_cap_drm.out The corresponding video device should be default to /dev/video0 ~ /dev/video3.
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Introduction Disk encryption on Android is based on dm-crypt, which is a kernel feature that works at the block device layer. Therefore, it is not usable with YAFFS, which talks directly to a raw nand flash chip, but does work with emmc and similar flash devices which present themselves to the kernel as a block device. The current preferred filesystem to use on these devices is ext4, though that is independent of whether encryption is used or not. [1] Let's encrypt! I will show the whole process first, and then point out the issue I noticed on i.MX6. To use this feature, go to settings and security as below: Encrypted phones need to set the numeric PIN, so click Screen lock to set password: Choose PIN: After setting up PIN code, the Screen lock is showed "Secured with PIN" as below: We can then click Encrypt phone to start: Note the words on this page, it needs start with a charged battery and the charger needs to be on. Click Encrypt phone button and it will ask PIN code setup before: Enter the PIN code and then has the confirmed page: Click Encrypt phone, it will reset framework and starting to encrypt: After running 100%: It then reset the device. When it boots, it will ask you enter the PIN to enter system. Check Setting -> Security again: The status showed Encrypted under Encrypt phone. Errors While Doing Encryption on i.MX6 In the following, I list the error I met and the way to fix. Orig filesystem overlaps crypto footer region.  Cannot encrypt in place It needs to make sure the filesystem doesn't extend into the last 16 Kbytes of the partition where the crypto footer is kept. The encryption in place and get_fs_size() in system/vold/cryptfs.c will check it, so needs to re-make data partition. sudo mke2fs -t ext4 /dev/sde7 1034000 -Ldata The original size is larger than 103400, so I used this value to reserved 16 Kbytes for crypto footer. device-mapper: table: 254:0: crypt: Error creating IV E/Cryptfs ( 2221): Cannot load dm-crypt mapping table. The actual encryption used for the filesystem for first release is 128 AES with CBC and ESSIV:SHA256. The master key is encrypted with 128 bit AES via calls to the openssl library. This is done by enable CONFIG_CRYPTO_SHA256 in kernel. Enable post_fs_data_done Vold sets the property vold.post_fs_data_done to "0", and then sets vold.decrypt to "trigger_post_fs_dat". This causes init.rc to run the post-fs-data commands in init.rc and init..rc. They will create any necessary directories, links, et al, and then set vold.post_fs_data_done to "1". Vold waits until it sees the "1" in that property. Finally, vold sets the property vold.decrypt to "trigger_restart_framework" which causes init.rc to start services in class main again, and also start services in class late_start for the first time since boot. This is done by: diff --git a/imx6/etc/init.rc b/imx6/etc/init.rc index 17cbd4c..f2823f2 100644 --- a/imx6/etc/init.rc +++ b/imx6/etc/init.rc @@ -203,7 +203,7 @@ on post-fs-data      # must uncomment this line, otherwise encrypted filesystems      # won't work.      # Set indication (checked by vold) that we have finished this action -    #setprop vold.post_fs_data_done 1 +    setprop vold.post_fs_data_done 1 Don't unmount data partition when cryptfs_restart After the steps above, it can finish encryption. But I found Android will crash after encryption and reboot. When data partition is encrypted, Android's init to mount /data will fail. The cryptfs.c here to try unmount will fail since the data partition isn't mounted before. diff --git a/cryptfs.c b/cryptfs.c index 052c033..fd05259 100644 --- a/cryptfs.c +++ b/cryptfs.c @@ -694,7 +694,7 @@ int cryptfs_restart(void)      if (! get_orig_mount_parms(DATA_MNT_POINT, fs_type, real_blkdev, &mnt_flags, fs_options)) {          SLOGD("Just got orig mount parms\n"); -        if (! (rc = wait_and_unmount(DATA_MNT_POINT)) ) { +        //if (! (rc = wait_and_unmount(DATA_MNT_POINT)) ) {              /* If that succeeded, then mount the decrypted filesystem */              mount(crypto_blkdev, DATA_MNT_POINT, fs_type, mnt_flags, fs_options); @@ -710,7 +710,7 @@ int cryptfs_restart(void)              /* Give it a few moments to get started */              sleep(1); -        } +        //}      } References: [1]: Notes on the implementation of encryption in Android 3.0 | Android Open Source
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Dithering Implementation for Eink Display Panel by Daiyu Ko, Freescale Dithering a.          Dithering in digital image processing Dithering is a technique used in computer graphics to create the illusion of color depth in images with a limited color palette (color quantization). In a dithered image, colors not available in the palette are approximated by a diffusion of colored pixels from within the available palette. The human eye perceives the diffusion as a mixture of the colors within it (see color vision). Dithered images, particularly those with relatively few colors, can often be distinguished by a characteristic graininess, or speckled appearance. Figure 1. Original photo; note the smoothness in the detail http://en.wikipedia.org/wiki/File:Dithering_example_undithered_web_palette.png Figure 2.Original image using the web-safe color palette with no dithering applied. Note the large flat areas and loss of detail. http://en.wikipedia.org/wiki/File:Dithering_example_dithered_web_palette.png Figure 3.Original image using the web-safe color palette with Floyd–Steinberg dithering. Note that even though the same palette is used, the application of dithering gives a better representation of the original b.         Applications Display hardware, including early computer video adapters and many modern LCDs used in mobile phonesand inexpensive digital cameras, show a much smaller color range than more advanced displays. One common application of dithering is to more accurately display graphics containing a greater range of colors than the hardware is capable of showing. For example, dithering might be used in order to display a photographic image containing millions of colors on video hardware that is only capable of showing 256 colors at a time. The 256 available colors would be used to generate a dithered approximation of the original image. Without dithering, the colors in the original image might simply be "rounded off" to the closest available color, resulting in a new image that is a poor representation of the original. Dithering takes advantage of the human eye's tendency to "mix" two colors in close proximity to one another. For Eink panel, since it is grayscale image only, we can use the dithering algorism to reduce the grayscale level even to black/white only but still get better visual results. c.          Algorithm There are several algorithms designed to perform dithering. One of the earliest, and still one of the most popular, is the Floyd–Steinberg dithering algorithm, developed in 1975. One of the strengths of this algorithm is that it minimizes visual artifacts through an error-diffusion process; error-diffusion algorithms typically produce images that more closely represent the original than simpler dithering algorithms. (Original) Threshold Bayer   (ordered)                                     Example (Error-diffusion): Error-diffusion dithering is a feedback process that diffuses the quantization error to neighboring pixels. Floyd–Steinberg dithering only diffuses the error to neighboring pixels. This results in very fine-grained dithering. Jarvis, Judice, and Ninke dithering diffuses the error also to pixels one step further away. The dithering is coarser, but has fewer visual artifacts. It is slower than Floyd–Steinberg dithering because it distributes errors among 12 nearby pixels instead of 4 nearby pixels for Floyd–Steinberg. Stucki dithering is based on the above, but is slightly faster. Its output tends to be clean and sharp. Floyd–Steinberg Jarvis,   Judice & Ninke Stucki                         Error-diffusion dithering (continued): Sierra dithering is based on Jarvis dithering, but it's faster while giving similar results. Filter Lite is an algorithm by Sierra that is much simpler and faster than Floyd–Steinberg, while still yielding similar (according to Sierra, better) results. Atkinson dithering, developed by Apple programmer Bill Atkinson, resembles Jarvis dithering and Sierra dithering, but it's faster. Another difference is that it doesn't diffuse the entire quantization error, but only three quarters. It tends to preserve detail well, but very light and dark areas may appear blown out. Sierra Sierra   Lite Atkinson                              2.     Eink display panel characteristic a.       Low resolution Eink only has couple resolution modes for display      DU                  (1bit, Black/White)      GC4                (2bit, Gray scale)      GC16              (4bit, Gray scale)      A2                   (1bit, Black/White, fast update mode) b.      Slow update time For 800x600 panel size (per frame)      DU                  300ms                              GC4                450ms                              GC16              600ms                               A2                   125ms 3.       3.     Effect by doing dithering for Eink display panel a.       Low resolution with better visual quality By doing dithering to the original grayscale image, we can get better visual looking result. Even if the image becomes black and white image, with the dithering algorism, you will still get the feeling of grayscale image. b.      Faster update with Eink’s animation waveform Since the DU/A2 mode could update the Eink panel faster than grayscale mode, with dithering, we can get no only the better visual looking result, but also we can use DU/A2 fast update mode to show animation or even normal video files. 4.       4.     Our current dithering implementation a.       Choose a simple and effective algorism Considering Eink panel’s characteristics, we compared couple dithering algorism and decide to use Atkinson dithering algorism. It is simple and the result is better especially for Einkblack/white display case. b.      Made a lot of optimization so that it will not affect update time too much With the simplicity of the Atkinson dithering algorism, we can also put a lot of effort to do the optimization in order to reduce the dithering processing time and make it practical for actual use. c.       Current algorism performance and result Currently, with Atkinson dithering algorism, our processing time is about 70ms. 5.       5.     Availability a.       We implemented both Y8->Y1 and Y8->Y4 dithering with the same dithering algorism. b.      Implemented into our EPDC driver with i.MX6SL Linux 3.0.35 version release. c.       Also implemented in our Video for Eink demo 6.       6.     References a.       Part of dithering introduction from www.wikipedia.org
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INTRODUCTION REQUIREMENTS KERNEL DRIVER DEVICE NODE NFC LIBRARY TESTING NFC READER REFERENCES 1. INTRODUCTION This document is a step by step guide of the AN11697 PN7120 Linux Software Stack Integration Guidelines application note that can be downloaded from http://www.nxp.com/documents/application_note/AN11697.pdf . It explains how to add the PN7120 driver and NFC libraries to a Linux OS running in the i.MX6Q. 2. REQUIREMENTS The board used in this document is the Udoo Board thanks to the easy pin access. More information about this board can be found at Ultimate Single Board Mini PC for Android and Linux - UDOO A modified FSL L3.14.28 BSP. The modifications can be found in these 2 documents Basic Device Tree for the Udoo Board and  U-Boot Migration Example . If you have followed the previous documents, you already have a working yocto image and toolchain (meta-toolchain), if not you must follow this awesome training first Yocto Training - HOME . The OM5577/PN7120S demonstration kit. You can find more details of this board at http://www.nxp.com/documents/user_manual/UM10878.pdf 3. KERNEL DRIVER According to the AN11697.pdf we must follow the below steps: From the Linux source directory: $ cd drivers/misc $ git clone https://github.com/NXPNFCLinux/nxp-pn5xx.git Add the below line in the Makefile of the current directory obj-y += nxp-pn5xx/ Include the driver config in the drivers/misc/Kconfig file source "drivers/misc/nxp-pn5xx/Kconfig" Export the environment variables $ source source /opt/poky/1.7/environment-setup-cortexa9hf-vfp-neon-poky-linux-gnueabi $ export ARCH=arm $ export CROSS_COMPILE=$TARGET_PREFIX $ make imx_v7_defconfig Using menuconfig include the driver as module (<M>).  Compile the modules and install the .ko files into the target rootfs. $ make  modules You can send the .ko files with scp $ make  INSTALL_MOD_PATH=~/Desktop/modules modules_install $ cd ~/Desktop/modules $ sudo scp -r lib/modules/3.14.28+g91cf351/kernel root@<board_ip>:/lib/modules/3.14.28+g91cf351/ 4. DEVICE NODE The PN7120 interfaces with an MCU or MPU via I2C interface, therefore the device must be described into a i2c node. The signals used in the PN7120 are shown below: As you can see besides power, ground and I2C lines, an IRQ and Reset pins are needed. These pins must be configured as GPIO and one must generate an interrupt to the iMX6Q. The chosen connection is shown below: To achieve the above configuration, the device tree must be changed. The changes consist on adding a device node in the corresponding I2C bus, describing the PN7120. &i2c1 {         clock-frequency = <100000>;         pinctrl-names = "default";         pinctrl-0 = <&pinctrl_i2c1>;         status = "okay";         pn547: pn547@28 {                 compatible = "nxp,pn547";                 reg = <0x28>;                 clock-frequency = <400000>;                 interrupt-parent = <&gpio6>;                 interrupt-gpios = <&gpio6 2 0>;                 enable-gpios = <&gpio5 22 0>;         }; }; The pinctrl_i2c1 phandle contains the I2C pins configuration. Make sure that the PADs connected to the PN7120 are not used in other device node. &iomuxc {         imx6q-udoo {                       ...                 pinctrl_i2c1: i2c1grp {                         fsl,pins = <                         MX6QDL_PAD_GPIO_5__I2C3_SCL             0x4001b8b1                         MX6QDL_PAD_GPIO_6__I2C3_SDA             0x4001b8b1                         >;                 };         }; }; After this you can generate the dtb file and send it with scp make dtbs sudo scp arch/arm/boot/dts/imx6q-udoo.dtb root@<board_ip>:/run/media/mmcblk0p1/imx6q-udoo.dtb NOTE: Attached you can find the complete dts and dtsi files used in this document. 5. NFC LIBRARY     To work with the PN7120 in Linux the libnfc-nci stack is needed. You can find more details in http://www.nxp.com/documents/application_note/AN11697.pdf​ . This sections explains how to cross-compile the libray and install the required files in the target (The below steps must be performed in the host). Get the library $  git clone https://github.com/NXPNFCLinux/linux_libnfc-nci.git Generate the configuration script $ ./bootstrap Mount the target rootfs to /mnt in the host. $ sudo mount /dev/sdX2 /mnt Generate the Makefile $ ./configure --host=arm-none-linux --prefix=/opt/poky/1.7/sysroots/x86_64-pokysdk-linux/usr --sysconfdir=/mnt/etc Build and install the source code $ make $ make install After a succesful bulding the libraries and a application demo are built in .libs directory. Copy the libaries to /usr/lib directory of the target and nfcDemoApp to /usr/sbin $ cd linux_libnfc-nci/.libs $ sudo cp * /mnt/usr/lib/ 6. TESTING NFC READER     To test the application you have to follow the below steps on the target: Install the .ko file $ insmod /lib/modules/3.14.28+g91cf351/kernel/drivers/misc/nxp-pn5xx/pn5xx_i2c.ko Run the nfcDemoApp $  nfcDemoApp poll You should get a console output like the shown below when placing a NFC tag next to the NFC reader. 7. REFERENCES     Integrating NFC Controller library with KSDK http://www.nxp.com/documents/application_note/AN11697.pdf http://www.nxp.com/documents/user_manual/UM10878.pdf
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