Few issues encountered trying to build L5.1.1_2.1.0 Android for i.MX6: (some of them can apply to Android M6 build also) Issue-1: OpenJDK-7 required to build L5.1.1_2.1.0 but not able to download/install in Ubuntu 16.04: solution: Ubuntu 16.04 and openjdk 7 - Ask Ubuntu =============================== sudo add-apt-repository ppa:openjdk-r/ppa sudo apt-get update sudo apt-get install openjdk-7-jdk =============================== Issue-2: without any modification, got error message like: "You have tried to change the API from what has been previously approved." during compilation. solution: follow the suggestion in the error message, do "make update-api" Issue-3: error messages like ========================================= external/libcxx/include/thread:149: error: unsupported reloc 43 clang: error: linker command failed with exit code 1 (use -v to see invocation) build/core/host_shared_library_internal.mk:44: recipe for target 'out/host/linux-x86/obj32/lib/libc++.so' failed make: *** [out/host/linux-x86/obj32/lib/libc++.so] Error 1 ========================================= related post on Internet: http://stackoverflow.com/questions/36048358/building-android-from-sources-unsupported-reloc-43 https://bbs.archlinux.org/viewtopic.php?id=209698 solution:(as mentioned in the link above) replaced "prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.15-4.6/x86_64-linux/bin/ld" with the symlink to "/usr/bin/ld.gold" so this should look like: ========================================= ~/myandroid/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.6/x86_64-linux/bin$ ls -l ld* lrwxrwxrwx 1 jimlin jimlin      16     May  6 14:48 ld -> /usr/bin/ld.gold -rwxrwxr-x 1 jimlin jimlin 1645584 May  6 11:24 ld.bfd -rwxrwxr-x 1 jimlin jimlin 3497448 May  6 11:24 ld.gold -rwxrwxr-x 1 jimlin jimlin 3497448 May  6 11:24 ld.org ========================================= to this point I can build L5.1.1_2.1.0 successfully.(on 2016, May, 12.) Issue-4: can't run the SD tool "fsl-sdcard-partition.sh" used to partition/format SD card in "~/myandroid/device/fsl/common/tools" root-cause: in Ubuntu 16.04, "sfdisk" tool doesn't support "-u" parameter: ================================== sfdisk from util-linux 2.27.1 -u, --unit S              deprecated, only sector unit is supported ================================== error message encountered when running the script: ================================== ~/myandroid/device/fsl/common/tools$ sudo ./fsl-sdcard-partition.sh /dev/sdc sfdisk: unsupported unit 'M' sfdisk: unsupported unit 'M' ================================== I've modified the script a bit to adapt the changes, as attached.

Multiple-Display means video playback on multiple screens. In case playback needs to be in a unique screen, the mfw_isink element must be used and some pipelines examples can be found on this link: GStreamer iMX6 Multi-Overlay. Number of Displays Display type Kernel parameters Pipelines # Set these shells variables before running the pipelines alias gl=gst-launch SINK_1="\"mfw_v4lsink device=/dev/video17\"" SINK_2="\"mfw_v4lsink device=/dev/video18\"" SINK_3="\"mfw_v4lsink device=/dev/video20\"" media1=file:///root/media1 media2=file:///root/media2 media3=file:///root/media3 2 hdmi + lvds video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24 video=mxcfb1:dev=ldb,LDB-XGA,if=RGB666 gl playbin2 uri=$media1 video-sink=$SINK_1 playbin2 uri=$media2 video-sink=$SINK_2 2 lvds + lvds video=mxcfb0:dev=ldb,LDB-XGA,if=RGB666 video=mxcfb1:dev=ldb,LDB-XGA,if=RGB666 gl playbin2 uri=$media1 video-sink=$SINK_1 playbin2 uri=$media2 video-sink=$SINK_2 2 lcd + lvds video=mxcfb0:dev=lcd,800x480M@55,if=RGB565 video=mxcfb1:dev=ldb,LDB-XGA,if=RGB666 gl playbin2 uri=$media1 video-sink=$SINK_1 playbin2 uri=$media2 video-sink=$SINK_2 3 hdmi + lvds + lvds video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24 video=mxcfb1:dev=ldb,LDB-XGA,if=RGB6 video=mxcfb2:dev=ldb,LDB-XGA,if=RGB666 gl playbin2 uri=$media1 video-sink=$SINK_1 playbin2 uri=$media2 video-sink=$SINK_2 playbin2 uri=$media3 video-sink=$SINK_3

Multiple-Overlay (or Multi-Overlay) means several video playbacks on a single screen. In case multiple screens are needed, check the dual-display case GStreamer i.MX6 Multi-Display $ export VSALPHA=1 $ SAMPLE1=sample1.avi; SAMPLE2=sample2.avi; SAMPLE3=sample3.avi; SAMPLE4=sample4.avi; $ WIDTH=320; HEIGHT=240; SEP=20 Four displays (2x2) $gst-launch \ playbin2 uri=file://`pwd`/$SAMPLE1 video-sink="mfw_isink axis-top=0 axis-left=0   disp-width=$WIDTH disp-height=$HEIGHT" \ playbin2 uri=file://`pwd`/$SAMPLE2 video-sink="mfw_isink axis-top=0 axis-left=`expr $WIDTH + $SEP` disp-width=$WIDTH disp-height=$HEIGHT" \ playbin2 uri=file://`pwd`/$SAMPLE3 video-sink="mfw_isink axis-top=`expr $HEIGHT + $SEP` axis-left=0   disp-width=$WIDTH disp-height=$HEIGHT" \ playbin2 uri=file://`pwd`/$SAMPLE4 video-sink="mfw_isink axis-top=`expr $HEIGHT + $SEP` axis-left=`expr $WIDTH + $SEP` disp-width=$WIDTH disp-height=$HEIGHT" Basic rotation, (2 x 1, normal and inverted) gst-launch \ playbin2 uri=file://`pwd`/$SAMPLE1 video-sink="mfw_isink axis-top=0 axis-left=0   disp-width=$WIDTH disp-height=$HEIGHT rotation=0" \ playbin2 uri=file://`pwd`/$SAMPLE2 video-sink="mfw_isink axis-top=`expr $HEIGHT + $SEP` axis-left=0 disp-width=$WIDTH disp-height=$HEIGHT rotation=3"

In some cases it is desired to directly have progressive content available from a TV-IN interface through the V4L2 capture device. In the BSP, HW accelerated de-interlacing is only supported in the V4L2 output stream. Below is a patch created against a rather old BSP version that adds support for de-interlaced V4L2 capture. The patch might need to be adapted to newer BSPs, However, the logic and functionality is there and should shorten the development time. This patch adds another input device to the V4L2 framework that can be selected to perform the deinterlacing on the way to memory. The selection is done by passing the index “2” as an argument to the VIDIOC_S_INPUT  V4L2 ioctl. Attached is also a modified the tvin unit test to give an example of how to use the new driver. An example sequence for running the test is as follows: modprobe mxc_v4l2_capture ./mxc_v4l2_tvin_vdi.out -ow 720 -oh 480 -ol 10 -ot 20 -f YU12 Some key things to note: This driver does not support resize or color space conversion on the way to memory. The requested format and size should match what can be provided directly by the sensor. The driver was tested on a Sabre AI Rev A board running Linux 12.02. This code is not an official delivery and as such no guarantee of support for this code is provided by Freescale.

1.  Software change for Certification Test Compared to standard Linux/Android release, you may need to do below software changes to implement the certification tests, it is applicable from imx_3.10.31_1.1.0 Linux BSP GA release, for the release before that, user may need to apply the related patches before doing below things, and some examples may be different for former releases, the user needs to change accordingly. See the detailed information in this document “How to do USB Compliance Test for 3.10.y kernel”. And there is also a link describes the patch for USB Certification Test: Patch to make i.MX6DQ USB to support test modes for certification test 2. I.MX6 series USB Certification Guide http://cache.freescale.com/files/microcontrollers/doc/user_guide/IMXUSBCGUG.pdf Include the descriptions of all the Certification Test requirements, equipment, procedures for I.MX6 series. For example, Host/Device High Speed Eye Diagram Test(眼图测试).   3. Description of USBCertification related Registers AN4589 Configuring USB on i.MX 6 Series Processors http://cache.freescale.com/files/32bit/doc/app_note/AN4589.pdf   4. I.MX6Q/I.MX6DL/I.MX6SL/ I.MX6SX Certification Reports, see attachments   5. Checklist and TPL, see attachments. Original Attachment has been moved to: I.MX6SX-Checklist-and-TPL.zip

Introduction This guide provides a step by step explanation of what is involved in adding a new WiFi driver and making a new WiFi card work well in a custom Android build. (This guide was written for Android 4.1 but should be applicable to previous Android releases and hopefully future releases.) Contents Understand how Android WiFi works Port WiFi driver. Compile a proper wpa_supplicant in your BoardConfig.mk Modify your wifi.c in HAL. Launch wpa_supplicant and dhcpcd services in init.rc. Several debug tips. Understand How Android WiFi Works As the following figure, Android wireless architecture can be divided into three parts: Java Framework(WifiManager, WifiMonitor etc..), HAL(wifi.c,wpa_supplicant,netd) kernel space modules(wireless stack, wifi drivers) Java Framework communicate with wpa_supplicant using native interface (wifi.c). Wpa_supplicant and netd uses wireless extension or nl80211 to control WiFi drivers. Port WiFi driver Usually WiFi driver is provided as a kernel module. There are mainly two types of Android WiFi architecture:nl80211 and wext. With the implementation of nl80211/cfg80211 many wireless drivers in main line kernel  support nl80211 interface instead of wireless extension. For different vendors’ WiFi drivers, writing one Android.mk to add its compile into Android is what you should do. Here take atheros’s AR6kl as an example: ath6kl_module_file :=drivers/net/wireless/ath/ath6kl/ath6kl_sdio.ko $(ATH_ANDROID_SRC_BASE)/$(ath6kl_module_file):$(mod_cleanup) $(TARGET_PREBUILT_KERNEL) $(ACP)         $(MAKE) -C $(ATH_ANDROID_SRC_BASE) O=$(ATH_LINUXPATH) ARCH=arm CROSS_COMPILE=$(ARM_EABI_TOOLCHAIN)/arm-eabi- KLIB=$(ATH_\ LINUXPATH) KLIB_BUILD=$(ATH_LINUXPATH)         $(ACP) -fpt $(ATH_ANDROID_SRC_BASE)/compat/compat.ko $(TARGET_OUT)/lib/modules/         $(ACP) -fpt $(ATH_ANDROID_SRC_BASE)/net/wireless/cfg80211.ko $(TARGET_OUT)/lib/modules/ include $(CLEAR_VARS) LOCAL_MODULE := ath6kl_sdio.ko LOCAL_MODULE_TAGS := optional LOCAL_MODULE_CLASS := ETC LOCAL_MODULE_PATH := $(TARGET_OUT)/lib/modules LOCAL_SRC_FILES := $(ath6kl_module_file) include $(BUILD_PREBUILT) Compile a proper wpa_supplicant in your BoardConfig.mk In Android’s external directory, there are two wpa_supplicant_* projects. For wext-based wifi driver, wpa_supplicant_6 can be used. For nl80211-based WiFi driver, wpa_supplicnat_8 can only be used. But if WiFi vendors supply their own customized wpa_supplicant, it will be much easier to debug the communication between wpa_supplicant and WiFi drivers. No matter which supplicant  you choose, just control their compile in your BoardConfig.mk. Take atheros’s ath6kl as an example: ifeq ($(BOARD_WLAN_VENDOR),ATHEROS) BOARD_WLAN_DEVICE                        := ar6003 BOARD_HAS_ATH_WLAN                      := true WPA_SUPPLICANT_VERSION                  := VER_0_8_ATHEROS WIFI_DRIVER_MODULE_PATH                  := "/system/lib/modules/ath6kl_sdio.ko" WIFI_DRIVER_MODULE_NAME                  := "ath6kl_sdio" WIFI_DRIVER_MODULE_ARG                  := "suspend_mode=3 wow_mode=2 ar6k_clock=26000000 ath6kl_p2p=1" WIFI_DRIVER_P2P_MODULE_ARG              := "suspend_mode=3 wow_mode=2 ar6k_clock=26000000 ath6kl_p2p=1 debug_mask=0x2413" WIFI_SDIO_IF_DRIVER_MODULE_PATH          := "/system/lib/modules/cfg80211.ko" WIFI_SDIO_IF_DRIVER_MODULE_NAME          := "cfg80211" WIFI_SDIO_IF_DRIVER_MODULE_ARG          := "" WIFI_COMPAT_MODULE_PATH                  := "/system/lib/modules/compat.ko" WIFI_COMPAT_MODULE_NAME                  := "compat" WIFI_COMPAT_MODULE_ARG                  := "" endif then you need to provide a proper wpa_supplicant.conf  for your device. wpa_supplicant.conf  is very important because the control socket for android is specified in this file(ctrl_interface=). This file should be copied to /system/etc/wifi. Minimum required config options in wpa_supplicant.conf : There are two different ways in which wpa_supplicant can be configured, one is to use a "private" socket in android namespace, created by socket_local_client_connect() function in wpa_ctrl.c and another is by using a standard UNIX socket. Android private socket ctrl_interface=wlan0 update_config=1 - Unix standard socket ctrl_interface=DIR=/data/system/wpa_supplicant GROUP=wifi update_config=1 Modify your wifi.c in HAL Here what you should do is modifying some codes like wifi_load_driver and wifi_unload_driver. For Broadcom or CSR’s wifi driver, you can directly use the original wifi.c. But for atheros’s ath6kl driver, there are total three  .ko modules to install. So some micro variables and codes need to be changed to adapt it. Launch wpa_supplicant and dhcpcd services in init.rc If you have configured to use android private socket, you should do like this: service wpa_supplicant /system/bin/wpa_supplicant -Dwext -iwlan0 -c / data/misc/wifi /wpa_supplicant.conf socket wpa_wlan0 dgram 660 wifi wifi disabled oneshot or if you have configured to use unix standard socket, you should do like this: service wpa_supplicant /system/bin/wpa_supplicant -Dwext -iwlan0  -c/data/misc/wifi/wpa_supplicant.conf disabled oneshot If WiFi driver is not “wext” but “nl80211”, you should change it to –Dnl80211. For dhcpcd, you should lunch it like the following: service dhcpcd_wlan0 /system/bin/dhcpcd -ABKL     class late_start     disabled oneshot The parameters “-ABKL” can largely enhance wifi connection speed.  About what “ABKL” stand for, you can refer to dhcpcd’s GNU manual. Several debug tips Incorrect permissions will result in wpa_supplicant not being able to create/open the control socket andlibhardware_legacy/wifi/wifi.c won't connect. Since Google modified wpa_supplicant to run as wifi user/group the directory structure and file ownership should belong to wifi user/group (see os_program_init() function in wpa_supplicant/os_unix.c ). Otherwise errors like: E/WifiHW  (  😞 Unable to open connection to supplicant on "/data/system/wpa_supplicant/wlan0": No such file or directory will appear. Also wpa_supplicant.conf should belong to wifi user/group because wpa_supplicant will want to modify this file. How to Enable debug for wpa_supplicant.               By default wpa_supplicant is set to MSG_INFO that doesn't tell much.                    To enable more messages:                 modify common.c and set wpa_debug_level = MSG_DEBUG                 modify common.h and change #define wpa_printf from if ((level) >= MSG_INFO) to if ((level) >= MSG_DEBUG)         3. WiFi driver’s softmac.               For most vendors’ WiFi driver, the mac address is fixed. We should add one softmac rule to let WiFi driver’s mac is unique for each board.

Graphics are a big topic in the Android platform, containing java/jni graphic framework and 2d/3d graphic engines (skia, OpenGL-ES, renderscript). This document describes the general Android graphic stack and UI features on Freescale devices. 1. Android Graphic Stacks All Android 3D apps and games have the following graphic stack: Android system UI and all Apps UI follow 2D graphic stack as below, the hardware render will accelerate Android 2D UI with GPU HW OpenGL-ES 2.0 to improve the whole UI performance. Hardware acceleration can be disabled on i.mx6 in device/fsl/imx6/soc/imx6dq.mk USE_OPENGL_RENDERER := false Then rebuild frameworks/base/core/jni, and replace libandroid_runtime.so Surfaceflinger is responsible of all surface layers composition, and  then generate the framebuffer pixmap for display devices. these graphic surface layers are from 2D/3D apps. Hwcomposer is the alternative module of Surfaceflinger with OpenGL-ES. Hwcomposer is used to combine the specific surface layers supported by specific vendor devices. Freescale i.MX6 devices use GPU 2D to combine most surface layers, and the system power can be reduced with GPU 2D instead of GPU 3D. The typical power saving case is video playback. Hwcomposer with GPU 2D can offload GPU 3D task when running game and benchmarks, it is proved to improve the overall system performance about 20%. 2. Performance measurment Show FPS for Android system performance For NFS boot you can set “debug.sf.showfps” to 1 in init.freescale.rc (“setprop debug.sf.showfps 1”) and then reboot the system. For SD or EMMC boot, you can issue command “setprop debug.sf.showfps 1” in console, then find system_server thread by top and kill it to reset the system. Graphic benchmarks for 3D capability measurement Quadrant Full test benchmark cover CPU, Memory, IO, 2D and 3D GLBenchmark http://www.glbenchmark.com/ NenaMark2 https://market.android.com/details?id=se.nena.nenamark2 An3DBench http://www.androidzoom.com/android_applications/tools/an3dbench_hnog.html AnTutu http://www.antutu.com/software.html 3DMark http://www.futuremark.com/benchmarks/3dmark06/introduction/ Browser benchmarks http://www.webkit.org/perf/sunspider/sunspider.html http://v8.googlecode.com/svn/data/benchmarks/current/run.html http://www.craftymind.com/guimark2/ http://www.craftymind.com/factory/guimark/GUIMark_HTML4.html http://themaninblue.com/writing/perspective/2010/03/22/ 3.  Android UI features Dual display with same content This feature is supported in the default image in Android i.MX 6 release package. In this feature, LVDS panel and HDMI output can be supported simultaneously. It is only enabled when the HDMI TV has been connected with the board. Overscan for TV devices Some TVs may miss display the contents in overscan area. To avoid the contents in overscan area being lost, the common implement is by underscanning with an adjustable black border and letitng the viewer adjust the width of the black border. The downscan operation is done by surfaceflinger when it does surface composition through HW OpenGL ES. There is no performance impact since all the work is done by GPU HW. Overscan can be configured in display setting in visual mode: 32 bits color depth 32bpp UI can be supported by adding “bpp=32” in uboot as below: setenv bootargs ‘… video=mxcdi1fb:RGB666,XGA,bpp=32 …’, also can configure it in display setting. Enable 32bpp frame buffer and application surface buffer will be allocate to RGBA8888 format instead of default RGB565 format, that means more system memory is allocated. After enabling 32bpp, if some applications still don't have better UI quality, check to see if  there is hard code to request RGB565 format surface (should request RGBA8888 format to get better quality). Sample code is attached to test for 32bpp (left is on 16bpp, right is on 32bpp) Display Visual Setting The display setting is the add-on feature in FSL Android release, it is very convenient for end-users to change display property, mostly for the following features: Dual display enablement Display color depth setting(16bpp, 32bpp) Overscan adjustment in horizontal and vertical orientation 4. Issue Diagnosis Application Compatibility Some Android applications may not run correctly on some Android releases. It may cause application compatibility, so check the application in other platforms. For example Neocore and Asphalt 5 can run on Eclair, Froyo, and Gingerbread, but will not correctly run on Honeycomb. GPU Compatibility Some game UIs may not correctly display on our Android release. When encountering this kind of issue, the customer can check whether it is caused by the game using an OpenGL extension which our GPU does not support. They can download another data package (for example not extension data package) to have a check. Others Enlarge GPU memory if you encounter UI abnormally displaying after running an application for a while. Some applications need Wifi connections, so monitor the console log to see whether there are any error reports.

Share my test procedure in the attachment.

(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.

Notes: First run the playback pipeline then the streaming pipeline. The above example streams H263 video and AMR audio data. Change codec format to your needs. In case where the iMX is the streaming machine, the audio encoder 'amrnbenc' must be installed before. This scenario has not been tested Shell variables and pipelines Playback machine (receiver) # On playback machine, set either IMX2PC or PC2IMX variables, then run the pipeline ## IMX2PC: Case where PC does the playback     AUDIO_DEC_SINK="rtpamrdepay ! amrnbdec ! alsasink "     VIDEO_CAPS="\"application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)H263-1998\""     VIDEO_DEC_SINK="rtph263pdepay ! ffdec_h263 ! autovideosink" ## End of IMX2PC Settings ## PC2IMX: Case where iMX does the playback     AUDIO_DEC_SINK="rtpamrdepay ! mfw_amrdecoder ! alsasink "     VIDEO_CAPS="\"application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)H263-1998\""     VIDEO_DEC_SINK="rtph263pdepay ! vpudec ! mfw_v4lsink " ## End of PC2IMX Settings PLAYBACK_AUDIO="udpsrc caps=\"application/x-rtp,media=(string)audio,clock-rate=(int)8000,encoding-name=(string)AMR,encoding-params=(string)1,octet-align=(string)1\" \             port=5002 ! rtpbin.recv_rtp_sink_1 \         rtpbin. ! $AUDIO_DEC_SINK \      udpsrc port=5003 ! rtpbin.recv_rtcp_sink_1 \      rtpbin.send_rtcp_src_1 ! udpsink port=5007 sync=false async=false" PLAYBACK_VIDEO="udpsrc caps=$VIDEO_CAPS port=5000 ! rtpbin.recv_rtp_sink_0 \         rtpbin. ! $VIDEO_DEC_SINK \         udpsrc port=5001 ! rtpbin.recv_rtcp_sink_0 \         rtpbin.send_rtcp_src_0 ! udpsink port=5005 sync=false async=false" PLAYBACK_AV="$PLAYBACK_VIDEO $PLAYBACK_AUDIO" # Playback pipeline gst-launch -v gstrtpbin name=rtpbin $PLAYBACK_AV Streaming Machine (sender) # On Streaming machine, set either IMX2PC or PC2IMX variables, then run the pipeline ## IMX2PC: Case where iMX does the streaming     IP=x.x.x.x # IP address of the playback machine     VIDEO_SRC="mfw_v4lsrc"     VIDEO_ENC="vpuenc codec=h263 ! rtph263ppay "    AUDIO_ENC="audiotestsrc ! amrnbenc ! rtpamrpay " ## END IMX2PC settings ## PC2IMX: Case where PC does the streaming     IP=y.y.y.y # IP address of the playback machine     VIDEO_SRC="v4l2src"     VIDEO_ENC="ffenc_h263 ! rtph263ppay "     AUDIO_ENC="audiotestsrc ! amrnbenc ! rtpamrpay " # END PC2PC settings STREAM_AUDIO="$AUDIO_ENC ! rtpbin.send_rtp_sink_1 \         rtpbin.send_rtp_src_1 ! udpsink host=$IP port=5002 \         rtpbin.send_rtcp_src_1 ! udpsink host=$IP port=5003 sync=false async=false \         udpsrc port=5007 ! rtpbin.recv_rtcp_sink_1" STREAM_VIDEO="$VIDEO_SRC ! $VIDEO_ENC ! rtpbin.send_rtp_sink_0 \         rtpbin.send_rtp_src_0 ! queue ! udpsink host=$IP port=5000 \         rtpbin.send_rtcp_src_0 ! udpsink host=$IP port=5001 sync=false async=false \         udpsrc port=5005 ! rtpbin.recv_rtcp_sink_0" STREAM_AV="$STREAM_VIDEO $STREAM_AUDIO" # Stream pipeline gst-launch -v gstrtpbin name=rtpbin $STREAM_AV

This document explains how to bring-up u-boot & Linux via JTAG This procedure has been tested on: i.MX6 Solo X Sabre SD i.MX6UL EVK Prerequistes: Get the latest BSP for your board. This procedure was tested with L4.1.15. Build the 'core-image-minimal' image to bring-up your board (Detailed steps here) Optional- Build a meta-toolchain for your device 1.- Set board to boot from Serial dowloader mode or set it to boot from the SD card and remove the sd card We basically want the board to stall in boot ROM to attach to the target. 2.- Connect JTAG probe and turn on the board The device should stall trying to establish a connection to download an image, this will allow us to attach to the target. 3.- Load Device Configuration Data In 'normal' boot sequence the boot ROM takes care of reading the DCD and configuring the device accordingly, but in this case we are skipping this sequence and we need to configure the device manually. The script used by Lauterbach to parse and configure the device is called dcd_interpreter.cmm and can be found here. Search for the package for your specific device. The DCD configuration for your board should be on your u-boot directory: yocto_build_dir/tmp/work/<your board>imx6ulevk/u-boot-imx/<u-boot_version>2016.03-r0/git under board/freescale/<name of your board>mx6ul_14x14_evk/imximage.cfg This file (imximage.cfg) contains all the data to bring up DRAM among other early configuration options. 4.- Load U-boot If an SREC file of U-boot is not present build it (meta-toolchain installed required) the SREC file contains all the information required by the probe to load it and makes this process easier. To build the SREC simply type: make <your board defconfig>mx6ul_14x14_evk_defconfig  (all supported boards are found under u-boot_dir/configs) make If you cannot build an SREC or do not want to, you can use the u-boot.imx (located under yocto_build_dir/tmp/deploy/images/<your board name>/) or u-boot.bin files but you will need to figure out the start address and load address for these files, this can be done by examining the IVT on u-boot.imx (here is a useful document explaining the structure of the IVT). Let U-boot run and you should see its output on the console I will try to boot from several sources but it will fail and show you the prompt. 5.- Create RAMDisk After building the core-image-minimal you will have all the required files under yocto_build_dir/tmp/deploy/images/<your board name>/ You will need: zImage.bin - zImage--<Linux Version>--<your board>.bin Device tree blob - zImage--<Linux Version>--<your board>.dtb Root file system - core-image-minimal-<your board>.rootfs.ext4 We need to create a RAMDisk out of the root file system we now have, these are the steps to do so: Compress current Root file system using gzip: gzip core-image-minimal-<your board>.rootfs.ext4 If you want to keep the original file use: gzip -c core-image-minimal-<your board>.rootfs.ext4 > core-image-minimal-<your board>.rootfs.ext4.gz Create RAMDisk using mkimage: mkimage -A arm -O linux -T ramdisk -C gzip -n core-image-minimal -d core-image-minimal-<your board>.rootfs.ext4.gz core-image-minimal-RAMDISK.rootfs.ext4.gz.u-boot Output: Image Name: core-image-minimal Created: Tue May 23 11:28:55 2017 Image Type: ARM Linux RAMDisk Image (gzip compressed) Data Size: 3017939 Bytes = 2947.21 kB = 2.88 MB Load Address: 00000000 Entry Point: 00000000 Here are some details on mkimage usage Usage: mkimage -l image -l ==> list image header information mkimage [-x] -A arch -O os -T type -C comp -a addr -e ep -n name -d data_file[:data_file...] image -A ==> set architecture to 'arch' -O ==> set operating system to 'os' -T ==> set image type to 'type' -C ==> set compression type 'comp' -a ==> set load address to 'addr' (hex) -e ==> set entry point to 'ep' (hex) -n ==> set image name to 'name' -d ==> use image data from 'datafile' -x ==> set XIP (execute in place) mkimage [-D dtc_options] [-f fit-image.its|-F] fit-image -D => set options for device tree compiler -f => input filename for FIT source Signing / verified boot not supported (CONFIG_FIT_SIGNATURE undefined) mkimage -V ==> print version information and exit 6.- Modify U-boot's environment variables Now we need to modify U-boot's bootargs as follows: setenv bootargs console=${console},${baudrate} root=/dev/ram rw We need to find out the addresses where u-boot will expect the zImage, the device tree and the initial RAMDisk, we can do it as follows: => printenv fdt_addr fdt_addr=0x83000000 => printenv initrd_addr initrd_addr=0x83800000 => printenv loadaddr loadaddr=0x80800000 Where: fdt_addr -> Device tree blob load address initrd_addr -> RAMDisk load address loadaddr -> zImage load address 7.- Load zImage, DTB and RAMDisk Now we know where to load our zImage, device tree blob and RAMDisk, on Lauterbach this can be achieved by running the following commands: Stop the target and execute: data.load.binary zImage.bin 0x80800000 data.load.binary Your_device.dtb 0x83000000 data.load.binary core-image-minimal-RAMDISK.rootfs.ext4.gz.u-boot 0x83800000 Let the device run again and deattach from the device in lauterbach this is achieved by: go SYStem.mode.NoDebug start the boot process on u-boot as follows: bootz ${loadaddr} ${initrd_addr} ${fdt_addr} You should now see the Linux kernel boot process on your terminal: After the kernel boots you should see its prompt on your terminal: Since we are running out of RAM there is no way for us to save u-boot's environment variables, but you can modify the source and compile u-boot with the new bootargs, by doing so you can create a Load script that loads all the binaries hits go and the boot process will continue automatically. One way to achieve this is to modify the configuration file under U-boot_dir/include/configs/<your board>.h find the mfgtool_args and modify accordingly. The images attached to this thread have been modified as mentioned.

Some Chinese customers using i.MX series SoC maybe encounter some issues when they download android , u-boot & kernel source code by 'git' command, the following steps will show customer how to get them: 1. Getting repo --No.1 methord # cd ~ # mkdir myandroid # mkdir bin # cd bin # git clone git://aosp.tuna.tsinghua.edu.cn/android/git-repo.git/ <if git failed, use : git clone https://aosp.tuna.tsinghua.edu.cn/android/git-repo.git/> # cd git-repo # cp ./repo ../ --No.2 methord # cd ~ # mkdir bin # curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo # chmod a+x ~/bin/repo [Note]Customers can select one of above to get "repo" 2. Modifying repo File Open ~/bin/repo file with 'gedit' and Change google address From        REPO_URL = 'https://gerrit.googlesource.com/git-repo' To        REPO_URL = 'git://aosp.tuna.tsinghua.edu.cn/android/git-repo'        like following: ## repo default configuration ## REPO_URL = 'git://aosp.tuna.tsinghua.edu.cn/android/git-repo' REPO_REV = 'stable' 3、Setting email address # cd ~/myandroid # git config --global user.email "weidong.sun@nxp.com" # git config --global user.name "weidong.sun" [ Email & Name should be yours] 4、Getting manifest # ~/bin/repo init -u https://aosp.tuna.tsinghua.edu.cn/android/platform/manifest -b android-5.1.1_r1 # cd ~/myandroid/.repo # gedit manifest.xml        Then change the value of fetch to " git://aosp.tuna.tsinghua.edu.cn/android/ ", like following: <manifest>   <remote name="aosp"            fetch="git://aosp.tuna.tsinghua.edu.cn/android/" />   <default revision="refs/tags/android-5.1.1_r1" ...... [Note] android-5.1.1_r1 is version of branch,customer can change it to another. 5、# ~/bin/repo sync          [Note] During runing repo sync, maybe errors will occur like the following: ...... * [new tag]         studio-1.4 -> studio-1.4 error: Exited sync due to fetch errors          Then 'repo sync' exits. But don't worry about it, continue to run the command please ! " ~/bin/repo sync", downloading source code will be continous. 6、Getting Cross Compiler # cd ~/myandroid/prebuilts/gcc/linux-x86/arm # git clone https://aosp.tuna.tsinghua.edu.cn/android/platform/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6 # cd arm-eabi-4.6 # git checkout android-4.4.3_r1 7、Getting linux kernel source code        Probably, customer can't normally get linux kernel by using "git clone" command, she can download it directly from the following weblink:        http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/        At first, create a temperary directory, then download kernel into the directory. see following steps: # cd ~ /Downloads # mkdir linux-kernel   Atfer downloading l5.1.1_2.1.0-ga.tar.gz, use 'tar zxvf l5.1.1_2.1.0-ga.tar.gz' command to decompress it.        Then you can find a subdirectory name " l5.1.1_2.1.0-ga" is created, linux source code is in the directory, we should copy all files in the directory to ~/myandroid/kernel_imx/ # cd ~/myandroid # mkdir kernel_imx # cd kernel_imx # cp -a ~ /Downloads/linux-kernel/l5.1.1_2.1.0-ga ./ 8、Getting uboot source code               Probably, customer can't normally get linux kernel by using "git clone" command, she can download it directly from the following weblink:       http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/        We can use similar way to that of linux kernel to get u-boot source code: # cd ~ /Downloads # mkdir u-boot        Download l5.1.1_2.1.0-ga.tar.gz file, and save it in ~ /Downloads/ u-boot, then decompress it, then u-boot source code will be in ~ /Downloads/ u-boot / l5.1.1_2.1.0-ga/, we should copy all file in the path to ~/myandroid/bootable/bootloader/uboot-imx/ # cd ~/myandroid/bootable/bootloader # mkdir uboot-imx # cd uboot-imx # cp -a ~ /Downloads/u-boot/l5.1.1_2.1.0-ga/* ./ 9、Patch android BSP source code        android_L5.1.1_2.1.0_consolidated-ga_core_source.gz is the name of patch. Run following command to patch android. # copy android_L5.1.1_2.1.0_consolidated-ga_core_source.gz /opt/ # tar zxvf android_L5.1.1_2.1.0_consolidated-ga_core_source.gz # cd /opt/ android_L5.1.1_2.1.0_consolidated-ga_core_source/code/ # tar zxvf L5.1.1_2.1.0_consolidated-ga.tar.gz # cd ~/myandroid # source /opt/ android_L5.1.1_2.1.0_consolidated-ga_core_source/code/ L5.1.1_2.1.0_consolidated-ga/ and_patch.sh # help # c_patch /opt/ android_L5.1.1_2.1.0_consolidated-ga_core_source/code/ L5.1.1_2.1.0_consolidated-ga/ imx_L5.1.1_2.1.0-ga        If everything is OK, the following logs will display on console:               **************************************************************        Success: Now you can build the Android code for FSL i.MX platform               ************************************************************** 10、Patch Freescale extended feathures code        Please refer to chapter 3.3 of Android_User's_Guide.pdf to patch another 2 files:        (1) android_L5.1.1_2.1.0_consolidated-ga_omxplayer_source.gz        (2) android_L5.1.1_2.1.0_consolidated-ga_wfdsink_source.gz [Note]       As for other steps, such as compiling etc, please refer to Android_User's_Guide.pdf that released by NXP. TICS team Weidong Sun 04/01/2016

In some customers’ design they use the different DRAM from the one used on our reference board. So customers need to customize the DRAM to make it work well on their design. About the i.MX6x hardware design customers can refer to IMX6DQ6SDLHDG.pdf and the section 5 DRAM interface requirements for migration on AN4397. After finishing the hardware design there are two tools important for the DRAM boot up and debug: DRAM Register Programming aid And DRAM Stress Test 1\DRAM Register Programming aid Our expert team create the script to make it easier to work on DDR initialization. You can see all the scripts on different chips and the link is: i.MX Design&amp;Tool Lists The script include 3 sections, when you open it you can see the details. Run basic DDR initialization and test memory and open a debugger memory window pointing to the DDR memory map starting address. Try writing a few words and verify if they can be read correctly. If not, re-check the DDR initialization sequence and if the DDR has been correctly soldered onto the board. It is also recommended to re-check the schematic to ensure the DDR memory has been connected to the SoC correctly. In some cases, a DRAM calibration routine may need to be executed. About the details use and introduction on this script you can refer to Freescale i.MX6 DRAM Port Application Guide-DDR3 After configure the DRAM, you need to use the DRAM Stress Test to perform calibrations the performance and then regulate some parameters. 2\DRAM Stress Test DDR_Stress_Tester is a software application for fine tuning DDR parameters and verifying DDR performance on i.MX6 boards. It performs write leveling, DQS gating, read/write delay calibration on the target board to match the layout of the board and archive the best DDR performance. In addition, the stress test can help the user to verify the DDR performance on their boards. The DDR stress test tool serves two purposes. First, it can perform calibrations for DDR3 to match the MMDC PHY delay settings with PCB for optimal DRAM performance. The process is fully automatic, and therefore the customers can get there DDR3 working in much shorter time. In addition, the tool can run a memory stress test to verify the DDR3 functionality as well as the reliability. The stress test can help verifying the hardware connections, MMDC registers parameters, and DDR3 mode registers setting. The most important purpose of the test is that it allows the customers to verify that the DDR3 operations are stable on their board. The newest version  of DRAM Stress Test tool you can see in our community: i.MX6/7 DDR Stress Test Tool V2.51 And the old version you can see in the follow link: i.MX6 DDR Stress Test Tool V1.0.3 About how to use this tool you can read the use guide. Besides , you also can refer to the Freescale i.MX6 DRAM Port Application Guide-DDR3 By the way, if customers use the different DRAM from our reference design when the use the mfgtool to download the images, they need to build manufacturing images for mfgtool. Take the Linux 3.14.52 BSP as an example: $ bitbake fsl-image-mfgtool-initramfs Hope this can help you.

Q:How use USB as both gadget mode and host mode usb USB_OTG? A: Hardware: imx6 sabresd board usb otg diagram, as follow Software:   You can use USB OTG port for both host mode and device gadget mode. There are 2 signals you should care: - USB_OTG_ID - USB_OTG_MODE (control power for usb vbus in host mode, this is EIM_D22 pin)   In device tree: reg_usb_otg_vbus: regulator@0 {                         compatible = "regulator-fixed";                         reg = <0>;                         regulator-name = "usb_otg_vbus";                         regulator-min-microvolt = <5000000>;                         regulator-max-microvolt = <5000000>;                         gpio = <&gpio3 22 0>;                         enable-active-high;                 };   pinctrl_usbotg: usbotggrp {                         fsl,pins = <                                 MX6QDL_PAD_GPIO_1__USB_OTG_ID           0x17059                                 MX6QDL_PAD_EIM_D22__GPIO3_IO22           0x80000000                         >;                 };   &usbotg {         vbus-supply = <&reg_usb_otg_vbus>;         pinctrl-names = "default";         pinctrl-0 = <&pinctrl_usbotg>;         disable-over-current;         srp-disable;         hnp-disable;         adp-disable;         dr_mode = "otg";                 status = "okay"; };  With above config, one can use OTG port for mouse, usb stick in host mode, and gadget mode for ADB...   https://community.nxp.com/message/943460 

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

A new version of the Pins Tool for i.MX Application Processors has been released and is available for download as desktop tool from Pins Tool for i.MX Application Processors|NXP. The pins Tool for i.MX Application Processors is used for pin routing configuration, validation and code generation, including pin functional/electrical properties, power rails, run-time configurations, with the following main features: Desktop application Muxing and pin configuration with consistency checking Multicore support ANSI-C initialization code Graphical processor package view Multiple configuration blocks/functions Easy-to-use device configuration Selection of Pins and Peripherals Package with IP blocks Routed pins with electrical characteristics Registers with configured and reset values Power Groups with assigned voltage levels Source code for C/C++ applications Documented and easy to understand source code CSV Report and Device Tree File Localized for English and Simplified Chinese Mostly Connected: On-Demand device data download Integrates with any compiler and IDE What's New Added Label support to give signals a name Added ‘Log’ and ‘Problems’ view to report conflicts between settings Added support for templates to store user configurations as starting point for new configurations Added ability to download and share data for devices, especially for off-network host machines i.MX header files are now automatically part of the device data Import of legacy Processor Expert .pe files Export of register defines Various bug fixes and documentation improvements The release notes of the desktop application are attached to this article. Import Processor Expert Files A new importer has been added to import legacy Processor Expert for i.MX files: Labels Signals can now have user defined labels: Templates, Kits, Boards and Processors When creating a new configuration, it offers Templates, Boards and Processors. Custom configurations can be stored as templates and then used for new configurations. Board Specific Functions With the provided board and kit configurations, there are now pre-configured initialization functions for major blocks on the board: Export Data To simplify downloading the device specific data for the desktop tool, the 'Export' function can be used to download and export the data. The data can be copied that way to another machine or all data for a set of devices can be loaded. Export Registers With the Export command the registers can be exported as text/source: This is used to store the register values: /*FUNCTION********************************************************************** * * Function Name : init_audmux_pins * Description   : Configures pin routing and optionally pin electrical features. * *END**************************************************************************/ #define INIT_AUDMUX_PINS_IOMUXC_AUD5_INPUT_DA_AMX_SELECT_INPUT_VALUE            0x00000000   /*!< Register name: IOMUXC_AUD5_INPUT_DA_AMX_SELECT_INPUT */ #define INIT_AUDMUX_PINS_IOMUXC_AUD5_INPUT_TXCLK_AMX_SELECT_INPUT_VALUE         0x00000000   /*!< Register name: IOMUXC_AUD5_INPUT_TXCLK_AMX_SELECT_INPUT */ #define INIT_AUDMUX_PINS_IOMUXC_AUD5_INPUT_TXFS_AMX_SELECT_INPUT_VALUE          0x00000000   /*!< Register name: IOMUXC_AUD5_INPUT_TXFS_AMX_SELECT_INPUT */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DI0_PIN02_VALUE                  0x00000002   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DI0_PIN02 */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DI0_PIN03_VALUE                  0x00000002   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DI0_PIN03 */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DI0_PIN04_VALUE                  0x00000002   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DI0_PIN04 */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DI0_PIN15_VALUE                  0x00000002   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DI0_PIN15 */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA16_VALUE               0x00000003   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA16 */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA18_VALUE               0x00000003   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA18 */ #define INIT_AUDMUX_PINS_IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA19_VALUE               0x00000003   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA19 */ ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ We hope you will find this new release useful. Thanks for designing with NXP! 

Here we show how to bootstrap the Debian Linux distribution from a PC to the i.MX6 sabre sd platform. While bootstrapping Debian on any architecture "natively" is pretty straightforward, "cross-bootstrapping" requires some techniques that we will explain. This document assumes you are able to boot a Linux kernel on your platform already. See this post for details on how to do it. Also, this document assumes you are using a Debian PC for preparing your SD card. You will require the following packages to be installed: binfmt-support qemu-user-static debootstrap Note: all the commands found in the following steps need to be run as root. Formatting the SD card We need to format the SD card with two partitions; one small FAT partition to contain the Linux kernel and its dtb, and one large ext4 partition, which will contain the root filesystem with the Debian userspace. Also, we need to make sure we leave some space for u-boot starting from offset 1024B. Here is an example SD card layout:   +-----+------+--------+-----+---------------+-----------------   | MBR |  ... | u-boot | ... | FAT partition | Linux partition ...   +-----+------+--------+-----+---------------+-----------------   0     512    1024           1M              ~257M (offsets in bytes) Here is an example SD card layout, as displayed by fdisk:   Device    Boot      Start         End      Blocks   Id  System   /dev/sdc1            2048      526335      262144    c  W95 FAT32 (LBA)   /dev/sdc2          526336     8054783     3764224   83  Linux (units: 512B sectors) You can format and mount the Linux partition with:   # mkfs.ext4 /dev/<your-sd-card-second-partition>   # mount /dev/<your-sd-card-second-partition> /mnt Your SD card second partition is typically something in /dev/sd<X>2 or /dev/mmcblk<X>p2. Do not forget to install u-boot and a Linux kernel as explained in those posts. Bootstrapping Debian First stage The first stage of Debian bootstrapping is done with:   # debootstrap --foreign --arch=armhf testing /mnt This will retrieve the base Debian packages from the internet, and perform a first stage of installation:   I: Retrieving Release   I: Retrieving Release.gpg   I: Checking Release signature   I: Valid Release signature (key id A1BD8E9D78F7FE5C3E65D8AF8B48AD6246925553)   I: Validating Packages   I: Resolving dependencies of required packages...   I: Resolving dependencies of base packages...   I: Found additional required dependencies: insserv libbz2-1.0 libcap2 libdb5.1 libsemanage-common libsemanage1 libslang2 libustr-1.0-1   I: Found additional base dependencies: libee0 libept1.4.12 libestr0 libgcrypt11 libgnutls-openssl27 libgnutls26 libgpg-error0 libidn11 libjson-c2 liblognorm0 libmnl0 libnetfilter-acct1 libnfnetlink0 libp11-kit0 libsqlite3-0 libtasn1-3 libxapian22   I: Checking component main on http://ftp.us.debian.org/debian...   (...)   I: Extracting util-linux...   I: Extracting liblzma5...   I: Extracting zlib1g... At this point, the necessary tools for second stage of installation are under /mnt/debootstrap/. Second stage The second stage needs to run natively; on an arm platform, that is. But we can use the combination of two techniques to perform this stage on the PC anyway:   # cp /usr/bin/qemu-arm-static /mnt/usr/bin/   # chroot /mnt /debootstrap/debootstrap --second-stage Those commands copy an arm emulator on the target filesystem, and use the chroot command to execute the second stage of the installation into the SD card, on the PC, with transparent emulation:   I: Installing core packages...   I: Unpacking required packages...   I: Unpacking libacl1:armhf...   I: Unpacking libattr1:armhf...   I: Unpacking base-files...   (...)   I: Configuring tasksel...   I: Configuring tasksel-data...   I: Configuring libc-bin...   I: Base system installed successfully. You can now remove /mnt/usr/bin/qemu-arm-static, or keep it for later, subsequent chroot under emulation. Finetuning the root filesystem For development it is handy to remove the root password on the target by removing the '*' from /mnt/etc/shadow on the SD card:   root::15880:0:99999:7::: Also, we can add the following line in /mnt/etc/inittab to obtain a login prompt on the UART:   T0:23:respawn:/sbin/getty -L ttymxc0 115200 vt100 You can now unmount the filesystem with:   # umount /mnt Boot! Your SD card is ready for booting. Insert it in the SD card slot of your i.MX6 sabre sd platform, connect to the USB to UART port with a serial terminal set to 115200 baud, no parity, 8bit data and power up the platform. At the time of writing u-boot tells the kernel to boot from the wrong partition by default, so we need to interrupt by pressing enter at u-boot prompt for the first boot and setup u-boot environment to fix this:   U-Boot > setenv mmcroot /dev/mmcblk0p2 rootwait rw   U-Boot > saveenv   Saving Environment to MMC...   Writing to MMC(1)... done As this is saved in the SD card it need only to be done once at first boot. You can reboot your board or type boot; your Debian system should boot to a prompt:   (...)   [ ok ] Starting periodic command scheduler: cron.   [ ok ] Running local boot scripts (/etc/rc.local).   Debian GNU/Linux jessie/sid debian ttymxc0   debian login: From there you may login as root. It is recommended to setup the network connection and install an ssh server inside the target for further development. Enjoy! See also... With the amounts of memory we have today in the systems, it is even possible to boot Debian in a ramdisk. See this post about busybox for the ramdisk generation. Another way of generating a root filesystem is by building it with buildroot. See and this post for details.

According to section 13.5 (Cortex-M4 Boot Requirements) of the i.MX6SX  Reference Manual : • Cortex-A9 always boots as the primary core. • Cortex-M4 does not have a boot ROM and at POR is not provided a clock. • Cortex-A9 ROM is responsible for the following: • Loading and authenticating A9 bootloader and initiating Cortex-M4 firmware as a unified image. • Setting up Cortex-M4 initial exception table in TCRAML • Launching the Cortex-M4 by enabling its clock. In addition :  M4 obtains minimal initial vector table, containing a) Initial Stack pointer b) Reset vector c) NMI vector from a fixed location (zero offset) in TCM(L) after A9 enables it’s clock. So, A9 (bootloader) is responsible for:     Configuring M4 initial vector table  in TCM(L) ;     Loading M4 code ;     Configuring CSU and RDC for TrustZone (if needed)       and A9/M4 domain separation ;     Enabling M4 clock.    Please look at the enclosed projects, which help to understand how to build, load and run startup codes for both Cortex-A9 and Cortex-M4 cores of i.MX6 SoloX.   Also note : the i.MX6 SoloX has two cores with different address mapping. Please refer to Table 2-1 (System memory map) for Cortex-A9 core and to Table 2-2 (CM4 memory map) for Cortex-M4 of the i.MX6 SoloX Reference Manual. To run Cortex-M4 it is needed to fill TCM(L), that is addressed as TCML ALIAS (from zero). The same memory is mapped to 0x007f8000 of the Cortex-A9 (non-reflected in the Table 2-1). Note, this area is accessible by the Cortex-A9 after M4 clock is enabled in CCM_CCGR3. The following resources may be helpful, when working with i.MX6 SoloX : “How to configure Real View ICE  and RealView debugger  to work with i.MX6 SoloX” https://community.freescale.com/docs/DOC-106198 “Integrating Processor Expert for i.MX and ARM GCC with Eclipse” https://community.freescale.com/docs/DOC-103736 “I.MX6SX start M4 from U-Boot with QSPI flash” https://community.freescale.com/message/499465 "Loading Code on Cortex-M4 from Linux for the i.MX 6SoloX and i.MX 7Dual/7Solo " http://cache.nxp.com/files/soft_dev_tools/doc/app_note/AN5317.pdf

                                                                                         Watch the Freescale i.MX team boot up Android 5.0 Lollipop in i.mx6 application processors—在线播放—优酷网，视频高清在线观看 The Freescale i.MX Android team has booted up Android 5.0 Lollipop in the SABRE platform for i.mx6 series. Google pushed all of the latest source for its Android release to AOSP on Nov. 5, and the Freescale Android Team started their work. With the previous 6 days to boot Android Lollipop up, the Freescale i.MX Android team enabled the basic features like connectivity, audio/video playback, sensors, inputs and display on day 7! You can see the some changes in the demo video at the beginning of the post. The Freescale i.MX Android team has closely followed almost every version of Android since it is released by AOSP and has good experience on it. Below are some snapshots and pictures for the Android Lollipop.