通常的音乐播放是这样一个流程： alsa将一段上层的应用空间和底层的物理空间通过mmap映射起来，然后DMA从被映射的物理空间往I2S的fifo传送数据。 现在有个客户想将FEC网络那边收到的数据中的audio数据分离出来，暂存到一段物理内存中，然后通过DMA传输到我们芯片的I2S fifo，从而节省掉数据在上层、底层之间来回调用的时间。 这就需要我们I2S这边支持通过DMA直接从一段物理内存拿数据。 为了较为方便的实现这一功能，通过对ALSA架构的分析，我保留了我们整个ASoC代码的架构，只是不让DMA从原来的mmap的地址拿数据，而是从我自己分配的DMA内存中拿数据。 258         uint8_t *wbuf; 259         uint8_t *index1; 261         wbuf = dma_alloc_coherent(NULL, 0x10000, &wpaddr, GFP_DMA); 265         for (i=0; i<0x10000; i++) { 269                         *(wbuf + i) = wav_data[i]; 273         } 333                 iprtd->desc = chan->device->device_prep_dma_cyclic( 334                         chan, wpaddr, 335 //                      chan, dma_addr, 336                         iprtd->period_bytes * iprtd->periods, 337                         iprtd->period_bytes, 338                         substream->stream == SNDRV_PCM_STREAM_PLAYBACK     ? 339                         DMA_TO_DEVICE : DMA_FROM_DEVICE); 代码实现上，实际上是比较简单的，可以套用以前做过的dma_m2m的部分代码。 现在我们要拿一些wav里面的audio数据。 linux可以用16进制的方法读wav里面的数据: hexdump -n 65700 -C audio44k16S.wav > wav_data_44100_s16_stereo.h将audio44k16S.wav 里面的audio数据用16进制的形式保存到wav_data_44100_s16_stereo.h这个文件里。 然后我们要编辑这个头文件里的audio数据，原数据是这种格式的： 00000000  52 49 46 46 12 63 0c 00  57 41 56 45 66 6d 74 20  |RIFF.c..WAVEfmt | 00000010  12 00 00 00 01 00 02 00  44 ac 00 00 10 b1 02 00  |........D.......| 00000020  04 00 10 00 00 00 66 61  63 74 04 00 00 00 b5 18  |......fact......| 00000030  03 00 64 61 74 61 d4 62  0c 00 58 01 f0 00 98 01  |..data.b..X.....| 00000040  56 01 3d 01 1e 01 d0 00  ae 00 81 00 35 00 40 00  |V.=.........5.@.| 00000050  dd ff f7 ff 90 ff 9f ff  1d ff 54 ff bb fe 18 ff  |..........T.....| 00000060  61 fe 1e ff e7 fd 5e ff  e4 fd 23 00 39 fe ee 00  |a.....^...#.9...| 我们要把它转换成符合我们要求的这种形式： ,0x63 ,0xf0 ,0x0f ,0xf0 ,0x7f ,0xf1 ,0x21 ,0xf1  ,0x89 ,0xf3 ,0xef ,0xf2 ,0x9d ,0xf5 ,0x8c ,0xf4 ,0x5f ,0xf7 ,0xd3 ,0xf5 ,0x8c ,0xf8 ,0x08 ,0xf7  ,0x4c ,0xf9 ,0x01 ,0xf8 ,0x74 ,0xf9 ,0x2e ,0xf8 ,0x1c ,0xf9 ,0x15 ,0xf8 ,0x09 ,0xf9 ,0x82 ,0xf7  ,0x45 ,0xf9 ,0xd1 ,0xf6 ,0x0b ,0xf9 ,0x1e ,0xf6 ,0xce ,0xf8 ,0xbe ,0xf5 ,0xd7 ,0xf8 ,0x9a ,0xf5  ,0xa8 ,0xf9 ,0xc7 ,0xf5 ,0xe0 ,0xfa ,0x3e ,0xf6 ,0x25 ,0xfc ,0x44 ,0xf7 ,0x44 ,0xfd ,0xa2 ,0xf8  ,0x9a ,0xfe ,0xea ,0xf9 ,0x25 ,0x00 ,0x94 ,0xfb ,0x16 ,0x02 ,0xec ,0xfc ,0xcb ,0x03 ,0xfe ,0xfd  ,0xef ,0x04 ,0xa5 ,0xfe ,0x45 ,0x05 ,0x0b ,0xff ,0x3b ,0x05 ,0x24 ,0xff ,0x34 ,0x05 ,0x94 ,0xff  ,0x06 ,0x05 ,0x13 ,0x00 ,0x6c ,0x04 ,0x82 ,0x00 这里有一个比较好的方法， 可以通过VIM 垂直编辑的方法较为轻松的实现。 vim垂直编辑： ctrl+v 然后上下左右移动选中，D删除选中的。 ctrl+v 选中， shift+i 可以在选中的地方加入想插入的字符。 将编辑过的数据放到uint8_t wav_data[]，赋值给wbuf,wbuf对应的物理地址wpaddr中的数据，就是上面wav中的audio数据。 wbuf = dma_alloc_coherent(NULL, 0x10000, &wpaddr, GFP_DMA);中的0x10000=1024*64是我们分配的dma内纯的大小，我们sdma是根据以下大小传输数据的： iprtd->period_bytes = 21844, iprtd->periods = 3 //21844*3=65532= 0xfffc 这样实际上DMA是不停的刷我们分配的内存里的数据，因为我们没有更新DMA内存里的数据，所以听到的是不断重复播放的声音片段。 刚开始时，我听这个片段，发现片段之间有较为明显的pop音，这是由于我截取的是一首音乐开始的部分，包含了wav包头数据，这不是音乐数据，将这个去除就可以了。

This white paper is a discussion of random hangs and other issues using Windows Embedded Compact on Freescale i.MX6 application processor and how they were solved. All information in this document applies to Windows Embedded Compact 7 and 2013 as well as all variants of the i.MX6.      

All, This document will help you to understand the " YOCTO PROJECT COMMUNITY LAYERS" and the "YOCTO PROJECT FREESCALE OFFICIAL RELEASE" differences and where the layer content is coming from.   Best Regards, Luis

The patch is based on jb4.3_1.1.1-ga_rc2. Merge some commits from kitkat.

The ads7846 driver that is distributed with yocto 1.6 (Daisy, Linux 3.10.17) does not support device tree configuration hooks. Attached is a patch for the ads7846 touchscreen driver to support device tree. Also added to the driver are hooks to ignore the requirement for a voltage regulator configuration.

                                                                                         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.

Hi, My board is imx6dl_sabreauto and I use android4.4.2 source!The system stop at "Freeing init memory", when the system boot. I found the boot message no have follow message: mmc0: new high speed DDR MMC card at address 0001 mmcblk0: mmc0:0001 SEM08G 7.39 GiB mmcblk0boot0: mmc0:0001 SEM08G partition 1 2.00 MiB mmcblk0boot1: mmc0:0001 SEM08G partition 2 2.00 MiB input: WM8962 Beep Generator as /devices/platform/imx-i2c.0/i2c-0/0-001a/input/input7 mmcblk0: p1 p2 p3 < p5 p6 p7 p8 > p4 mmcblk0: p4 size 13336576 extends beyond EOD, truncated asoc: wm8962 <-> imx-ssi.1 mapping ok input: wm8962-audio DMIC as /devices/platform/soc-audio.5/sound/card0/input8 input: wm8962-audio Headphone Jack as /devices/platform/soc-audio.5/sound/card0/input9 mmcblk0boot1: unknown partition table Please help me! Thank  you!

  The VAR-SOM-SOLO small form factor System-on-Module carries an advanced feature-set and broad connectivity options, making it an ideal solution for customers and products in the embedded market.   Staying on-trend with the market’s shift towards a cost-effective highly integrated off-the-shelf solution, the VAR-SOM-SOLO from Variscite levels the playing ground for a broad spectrum of embedded products. Bringing all the benefits of the widely successful VAR-SOM-MX6, the VAR-SOM-SOLO from Variscite carries much smaller dimensions and a slim lined price-point.  Features include Freescale’s i.MX6 1GHz Cortex-A9, SLC NAND, eMMC, dual band Wi-Fi/BT with MIMO, USB, Gigabit Ethernet, A/V interfaces and industrial operating temperatures. The VAR-SOM-SOLO utilizes a standard SO-DIMM 200pins interface to the carrier board, fully pin-to-pin compatible with the VAR-SOM-MX6.   Ohad Yaniv, Variscite’s CEO, explains the strategy behind the new System-on-Module: “In today’s market, we believe the compact VAR-SOM-SOLO presents a true synergy between an impressive feature set and an affordable price-point. We feel the newly introduced SoM reflects a constantly evolving embedded application concept that requires advanced multimedia features, in a compact and cost efficient solution.”   Key features include:   - Freescale i.MX6 1000MHz single Cortex-A9   - Up to 1GB DDR3, 512MB SLC NAND and 64GB eMMC   - Certified Wi-Fi 802.11 a/b/g/n 2.4/5GHz with optional 2x2 MIMO   - Bluetooth 4.0/BLE   - Full 1080p video encode/decode capability   - Vivante GPU 2D/3D graphics accelerator   - Display: 2x LVDS, HDMI1.4, MIPI DSI   - 10/100/1000 Mbps Ethernet   - USB 2.0: Host, OTG   - PCIe   - Audio In/Out   - Camera inputs: MIPI CSI, parallel   - Dual CAN, UART, I2C, SPI   - Industrial temperature -40 to 85°C   - Dimensions: 33mm x 68mm x 4mm   - OS: Linux Yocto & Ubuntu, Android, WEC 7 & 2013   Availability and Pricing: The VAR-SOM-SOLO is available now. Pricing starts at 42USD. Contact [email protected] or +972 9 9562910 for more information.   About Variscite: Variscite is a leading System on Modules (SoM) and Single-Board-Computer (SBC) design and manufacture company. A trusted provider of development and production services for a variety of embedded platforms, Variscite transforms clients’ visions into successful products.   Learn more about Variscite, visit www.variscite.com    

We have validated Toshiba Smart NAND in our i.MX6SX platform, and boot successfully. The results are as below: 1. chip part number: THGBR2G5D1JTA00,  page_size: 16k+64  pages_per_block: 256 2. test platform: i.MX6SX Some information to take care of: 1. The pin assignment of smart nand is different from common raw nand, that is, Nand pin1 must connect to Vcc, pin2 connects to Vss, pin23 connects to VssQ, pin24 connects to VccQ, pin38 connects to VccQ 2. The ECC layout of FCB page itself must be set according to the i.MX6SX RM, otherwise FCB can't be read correctly. 3. EccBlock0EccType and EccBlockNEccType in FCB must be set as 0, and raw data can be put in DBBT and firmware without any ECC check codes.

RidgeRun provides a fully featured Embedded Linux Software Development Kit for Freescale iMX6 based applications processors. Freescale iMX6 platform delivers high performance, power efficient applications processors with a robust support network and software portfolio including open source. The complete platform allows for differentiation and rapid development of applications from wireless handsets to other multimedia-enhanced devices. The i.MX6 series processors are a scalable multicore platform that includes single-, dual- and quad-core families based on the ARM® Cortex™-A9 architecture. This architecture is a robust - cross industry and product platform. Whether your product is targeted at consumer electronics, industrial, automotive or security related, this flexible, scalable architecture combined with RidgeRun's easy-to-use SDK's and extension products allows you to concentrate your effort of differentiating features and not product infrastructure. FEATURES Boot loader 2013.07 Linux kernel 3.0.35-4.0.0 Gstreamer-0.10.36 Freescale gst-plugins 3.0.7 Hardware based audio and video codecs SD and NFS file system support Boot from SD3, SD4 or SPI-NOR with an easy installation (Boundary devices boards only) Toolchain to linaro 2012.03 for software floating point and 2013.03 for hardware floating point support For more info please contact: [email protected] or Please Click -> Contact Us

Ridgerun SDK for iMX6 based boards now supports the X11 protocol. The server-client based protocol is now supported by our professional SDK using hardware floating point which enables a high performance and provides all the advantages that comes with X.  In the RidgeRun SDK you'll also find complete integration of Qt4.8.5 using an X-based windowing system. We currently support Matchbox and Enlightenment which is a complete desktop environment. Contact RidgeRun for more details at : [email protected] or Please Click -> Contact Us RidgeRun Home Page : www.ridgerun.com RidgeRun iMX6 based solutions : iMX6 Based Solutions

The i.MX 6 D/Q/DL/S/SL  Linux L3.0.101_4.1.1 Patch release is now available on [www.freescale.com]www.freescale.com ·          Target HW boards o   i.MX6DL  SABRE SD board o   i.MX6Q  SABRE SD board o   i.MX6DQ SABRE AI board o   i.MX6DL SABRE AI board o   i.MX6SL EVK board This patch release is based on the i.MX 6 Linux 3.0.35_4.1.0 release. The purposes of this patch release are as follows: ·         To fix the BSP multimedia GPU bugs ·         To upgrade the Linux kernel to v3.0.101 ·         To upgrade the multimedia library ·         To upgrade the GPU driver and library to 4.6.9p13 Please consult the release notes for more details. ​

The i.MX 6 D/Q/DL/S/SL  Linux L3.10.17_1.0.2 Patch release is now available on www.freescale.com ·          Target HW boards o   i.MX6DL  SABRE SD board o   i.MX6Q  SABRE SD board o   i.MX6DQ SABRE AI board o   i.MX6DL SABRE AI board o   i.MX6SL EVK board This patch release is based on the i.MX 6 Linux L3.10.17_1.0.2 BSP release. ·         Release Description o    Kernel branch: imx_v2013.04_3.10.17_1.0.0_ga o    U-Boot branch: imx_3.10.17_1.0.0_ga o    Graphics: gpu-viv-bin-mx6q, 3.10.17_1.0.2 o    Graphics: gpu-viv-g2d, 3.10.17_1.0.2 o    Graphics: Xorg-driver, 3.10.17_1.0.2 ·         Patch Description Please consult the release notes.

As the Voice over IP (VoIP) market grows, the next evolution of the market is Video and Voice over IP (V2IP). iWave’s iW-RainboW-G15S is a Pico-ITX Single Board Computer (SBC) which has a Freescale’s i.MX6 DualLite ARM Cortex-A9 core based CPU which can operate up to 800MHz speed/core with 1GB (expandable) DDR3 RAM. iWave has provided V2IP on iWave’s Pico ITX i.MX6 which gives more quality in video and audio streaming. iWave has expertise in HD video streaming over V2IP. The SIP(Session Initiation Protocol) protocol for connection between i.MX6 PICO ITX board and host PC which is used in the application Linphone through network (Ethernet). Linphone is a comprehensive solution consisting of an extensive set of algorithms and codecs designed for Digital Voice and Video applications. Above design can be utilized for peer to peer communication between i.MX6 PICO ITX single board computer and PC with Android OS. The i.MX6 single board computer and PC are connected to an Ethernet. The Audio CODEC used on the iMX6 PICO ITX dev board is ALC5610 from Realtek with inbuilt Headphone amplifier and MIC which is used to provide a complete audio solution for portable products. The video pixel rates are typically from 25 MHz up to 297 MHz, but HDMI can support higher rates up to 340 MHz’s i.MX6 PICO ITX board supports LVDS connector to connect different LVDS LCDs. It also supports backlight connector with 15V 300mA output for LCD backlight. iWave's i.MX 6 PICO ITX SBC supports 8/10bit CMOS Camera Interface. External clock for camera is provided using on board Oscillator of frequency 26MHz. i.MX6 CPU supports MIPI CSI interface. The V2IP systems use some existing standard video codec and audio codec to reduce the program material to a bit stream and then use an Internet Protocol (IP) network to carry that bit stream encapsulated in stream of IP packets. This is typically accomplished using some variant of the RTP protocol. Freeescale i.MX6 multimedia applications processor provides sufficient power to provide high-quality audio through wideband audio, in-call audio and video recording on flash. Image: V2IP on iWave’s Android i.MX6 Pico ITX Single Board Computer Video Streaming Platform feature: Pico ITX board with i.MX6 dual lite CPU 320X240p camera OS: Android jelly-bean (4.3) MIC HDMI with 1920X1080p display Android NDK and SDK H264 video codec Freescale’s VPU     For further information or enquiries please write to [email protected] or visit www.iwavesystems.com

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.

Introduction There are four boot logos in kk4.4.3_2.0.0-beta  system at first: uboot logo\linux logo\android init logo\android animation. We plan to use uboot logo to cover linux logo and android init logo so that we  can combine first three logoes into one logo.This guide provides a step by step explanation of how to transfer uboot UI to  linux kernel and android init smoothly on board sasbresd_6dq sabresd_6dl. The core ideas of the patch: need to  keep display clock from uboot to kernel. When kernel boot up , we do not break the frambuffer for that it stores uboot logo data. need to disable show android init logo. what do the patch do in uboot 1、 can not shut down video after uboot is over.The patch delete releted code in function  arch_preboot_os() 2、 keep hsp clock (ipu clock) the same with linux 3.10 the below is the setting in sabrasd DQ board: osc(24MHz) -> pll2(528MHz) -> mmdc_ch0(528MHz) -> ipu1_hsp_clk(264MHz) the below is the setting in sabrasd DL board: osc(24MHz) -> pll3(480MHz) -> pll3_pdf1(540MHz) -> ipu1_hsp_clk(270MHz) 3、 keep pixel clock the same with linux 3.10 the below is the setting in sabrasd DQ board: osc(24MHz) -> pll2(528MHz) -> pll2_pfd0(452.57MHz) -> ldb_di1(64.65MHz) -> ipu1_di1(64.65MHz) -> ipu1_pixel(64.65MHz) the below is the setting in sabrasd DL board: osc(24MHz) -> pll2(528MHz) -> pll2_pfd0(452.57MHz) -> ldb_di1(64.65MHz) -> ipu1_di1(64.65MHz) -> ipu1_pixel(64.65MHz) 4、 keep pwm clock In kernel,there is a 100% duty pwm to drive lvds panel.So the patch set the pad SD1_DATA3 to a 100% duty pwm pin. 5、 add fbbase and fbmem to bootargs the fbbase is the uboot logo’s phy addr. So the patch pass the parament to kernel through cmdline.we should allocate address aligned 1M for linux 3.10 reserve address aligned by 1 M. what do the patch do in linux 3.10 1、 reserve the address which come from fbbase 2、 keep  ipu related clock when system init the clock in clk-imx6q.c The patch  enable ldb_di1_clk、ipu1_di1_clk、ipu1_clk、pwm1_clk.  Do not disable pll2 and pll3 related clock for the clock may be the source of  ipu clock. Although we enable ldb_di1_clk、ipu1_di1_clk and so on in register, we need to use the function clk_prepare_enable(). Because  the system may close some clocks for their user count is 0(if we use clk_prepare_enable(),it and it’s parent  user count will add 1 ) 3、 disable cabc which will light the panel according the content. Change cabc_enable in dts file. 4、 Move global alpha and color key setting in probe  after framebuffer is registered. Delay       register IPU interrupts used by framebuffer  until IPU hsp clock is enabled.Because global alpha and color key setting and register IPU interrupts may disable hsp clock. disable show android init logo android init logo is the text"android_". we need disable to show it so that the former three logos looks the same logo.The patch 92-system_core solve this problem. The environment of the patch: Hardware: SABRASD DQ&DL Soft ware: kk4.4.3_2.0.0-beta on linux 3.10 How to use the patch: $ cd my_android/kernel_imx/ $ patch -p1 < ./92-kernel_v2 $ cd my_android/bootable/bootloader/uboot-imx/ $ patch -p1 < ./92-uboot_v2     $ cd my_android/system/core $ patch -p1 < 92-system_core Note:      1、 If you want to have this feature on sabraSD dq&dl board,this patch is OK .After you use this patch, you want to change to  other board such as sx, you may meet this problem that the kernel logo penguin don’t appear. You may change this file: arch/arm/configs/imx_v7_android_defconfig                 CONFIG_LOGO=y                 CONFIG_FRAMEBUFFER_CONSOLE=y                 CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y                 #CONFIG_MX6_CLK_FOR_BOOTUI_TRANS=y                 #CONFIG_MX6_CLK_FOR_BOOTUI_TRANS_LVDS_IPU1_DI1=y

This is an example of QR code encoding using i.MX28. The encoded QR image can show on the LCD display directly using frame buffer and the image saved as a BMP file. Board : i.MX28EVK BSP : L2.6.35_1.1.0_130130_source QR Code Lib:  qrencode-3.4.4.tar.gz Download from https://fukuchi.org/works/qrencode/ Libqrencode is a C library for encoding data in a QR Code symbol. This library is a free software made by Kentaro Fukuchi. Build the QR Code Lib source code into rootfs. 1. Create a new folder in <ltib>/dist/lfs-5.1/.     e.g. <ltib>/dist/lfs-5.1/qrencode 2. Copy the qrencode.spec to this new created folder 3. Build the source code    ./ltib –p qrencode.spec –m prep    ./ltib –p qrencode.spec –m scbuild    ./ltib –p qrencode.spec –m scdeploy Create and build the application in unit_test: - I use the existing unit_test package to build my application code. 1. Extract the source code of unit_test    ./ltib –p imx-test –m prep 2. cd <ltib>/rpm/BUILD/imx-test-2.6.35.3-1.1.0/test 3. mkdir qr_test 4. copy the Makefile and qr_test.c to qr_test folder 5. Build the unit_test     ./ltib –p imx-test  –m scbuild     ./ltib –p imx-test  –m scdeploy After built the code successfully, the qr_test.out will be generated in the unit_test folder. I start the board with NFS, so I can run the qr_test.out on the board directly. The command is : ./qr_test.out   (the default QR encode text is “http://www.freescale.com”) Or input the new text like this : ./qr_test.out –t https://community.freescale.com/community/imx The QR code  show on the display: And the BMP files will be generated in the unit_test folder.

The i.MX 6 D/Q/DL/S/SL  Android JB4.3_1.1.1 Patch release is now available on www.freescale.com ·         Target HW boards o   i.MX6DL  SABRE SD board o   i.MX6Q  SABRE SD board o   i.MX6DQ SABRE AI board o   i.MX6DL SABRE AI board o   i.MX6SL EVK board This patch release is based on the i.MX 6 Android JB 4.3_1.1.0-GA BSP release. ·         Release Description o   To upgrade the GPU kernel and libraries to improve GPU stability o   To handle the Android SDK build failure o   To improve FSL OMX The table below describes the contents of this release.      Release Description Patches Contains the patches included in this release. The patches   are described in “Patch Description”. Documentation Contains the following document: • i.MX 6 Android JB 4.3_1.1.1 Patch Release Notes: This   document. ·         Patch Description Please consult the release notes.

Some questions arise when we think about the Android boot sequence. What is the Zygote, init.rc, what is the difference between the linux kernel and the android linux kernel?. This document is intended to explain how the booting process runs. Consider the following graph: Step 1: Power On and System Startup When we press the power button, the Boot ROM code starts executing from a pre-defined location which is hardwired in ROM. It loads the Bootloader into RAM and starts executing. Step 2: Bootloader The bootloader is a small program which runs before Android does. This is NOT part of the Android operating system. The bootloader is the place where manufacturer puts their locks and restrictions. The bootloader executes in two stages. In the first stage it detects external RAM and loads a program which helps in the second stage. In the second stage, the bootloader setups the network, memory, etc, which requires to run kernel. The bootloader is able to provide configuration parameters or inputs to the kernel for specific purposes. The bootloader can be found at: <android source>/bootable/bootloader/legacy/usbloader This legacy loader contains 2 important files: 1- Init.s :: Initializes stacks, zeros the BSS segments and  call_main() in main.c 2- Main.c :: Initializes hardware (clocks, board, keyboard, console) and creates linux tags. Step 3: Kernel The Android kernel starts in a similar way as the linux kernel.  As the kernel launches, is starts to setup cache, protected memory, scheduling and loads drivers. When the kernel finishes the system setup, it looks for “init” in the system files. What is the difference between the linux and android kernels?, here's a list of changes/addons that the Android Project made to the Linux kernel: Binder: It is an Android specific interprocess communication mechanism and remote method invocation system. ashmem:  "Android Shared Memory". It is a new shared memory allocator, similar to POSIX SHM but with a different behavior and sporting a simpler file-based API. pmem: "Process memory allocator": It is used to manage large (1-16+ MB) physically contigous regions of memory shared between userspace and kernel drivers. logger:  This is the kernel support for the logcat command. wakelocks: It is used for power management files. It holds the machine awake on a per-event basis until wakelock is released. oom handling: It kills processes as available memory becomes low. alarm manager: It lets user space tell the kernel when it would like to wake up. RAM_CONSOLE: Allows to save kernel printk messages to a buffer in RAM, so that after a kernel panic they can be viewed in the next kernel invocation. USB gadget driver for ADB yaffs2 flash filesystem Step 4: init process Init is the very first process, we can say it is a root process, or the grandfather of all processes. The init process has two responsibilities.      1- Mounts directories like /sys , /dev    or /proc      2- Runs init.rc script - The init process can be found at /init :: <android source>/system/core/init - Init.rc file can be found at :: <android source>/system/core/rootdir/ Android has specific format and rules for init.rc files. More information about this rules can be found in: What is inside the init.rc and what is it used for. At  this stage, you can finally see the Android logo in your screen. Step 5: Zygote and Dalvik In Java, we know that a separate Virtual Machine instance will popup in memory for separate per app, but in the case of Android, the VM should run as quick as possible for an app. But what happens if you have several apps thus launching several instances of the Dalvik (VM)?, it would consume an immense amount of memory. To overcome this problem, the Android OS has a system called “Zygote”.  The Zygote enables code sharing across the Dalvik VM, achieving a lower memory footprint and minimal startup time.  Zygote is a virtual machine process that starts at system boot. The Zygote preloads and initializes core library classes. The Zygote loading process: Load Zygote Init class: <android source>/frameworks/base/core/java/com/android/internal/os/ZygoteInit.java registerZygoteSocket() :: It registers a server socket for zygote command connections. preloadClasses() :: Is a simple text file that contains a list of classes that need to be preloaded, you can find the file at <android source>/framework/base preloadResources()  :: Everything that is included in the android.R file will be loaded with this method (themes and layouts). At this time, you can see the boot animation. Step 6: System service After the above steps are completed,  Zygote launches the system services.  The Zygote forks a new process to launch the system services. Core services: Starting power manager Creating the Activity Manager Starting telephony registry Starting package manager Set activity manager service as system process Starting context manager Starting system contact providers Starting battery service Starting alarm manager Starting sensor service Starting window manager Starting Bluetooth service Starting mount service Other services: Starting status bar service Starting hardware service Starting NetStat service Starting connectivity service Starting Notification Manager Starting DeviceStorageMonitor service Starting Location Manager Starting Search Service Starting Clipboard Service Starting checkin service Starting Wallpaper service Starting Audio Service Starting HeadsetObserver Starting AdbSettingsObserver Now we have finally completed the booting process (system service are up and running in memory). Need to analyze the Android Bootup? The logcat ::  Use adb to get the booting process events from the logcat. ‘adb logcat –d –b events | grep “boot” ‘adb logcat –d | grep preload’ More information about ADB can be found here: Using ADB with your Sabre Board

The init file is a key component of the Android boot sequence. It is a program to initialize the elements of the Android system.  Unlike Linux, Android uses its own initialization program. This Android init program processes 2 files, and it executes the commands it finds in both programs. These programs are: ‘init.rc’ and ‘init<machine name>.rc’ (this machine name is the name of the hardware that Android is running on). What does each program contain?: init.rc provides the generic initialization instructions init<machine name>.rc provides specific initialization instructions init<machine name>.rc is imported by the init.rc program. What is the syntax of these .rc files? The android init language consists of 4 classes of statements: Actions, Commands, Services and Options. Actions and Services declare new sections. All the commands or options belong to the section most recently declared. Actions and Services have to have unique names. If a second Action or Service has the same name of a previous one, it is ignored. Actions Actions are sequences of commands. They have a trigger which is used to determine when the action should occur. Actions take following form. On <trigger> <command> <command> <command>… Services Services are programs which init launches and (optionally) restart when it exists Services take the following form. Service <name> <patchname>  [argument] <option> <option>… Options Options are modifiers to services. These affect how and when init runs a service. Critical This is a device-critical service. If it exits more than four times in four minutes, the device will reboor into recovery mode. Disabled This service will not automatically start with its class. It must be explicitly started by name. Setenv <name> <value> Set the environment variable <name> to <value> in the launched process. User <username> Change to username before executing this service. Currently defaults to root. Group <groupname> [<groupname>] Change to groupname before executing this service. Oneshot Do not restart the service when it exists Class <name> Specify a class name for the service. All services in a named class may be started or stopped together. Onrestart Execute a command when service restarts Triggers Triggers are strings which can be used to match certain kinds of events and used to cause an action to occur. Boot This is the first trigger that will occur when init starts (after /init.conf is loaded) Commands: Exec <path> [<arguments>] Fork and execute a program (<path>). This will block until the program completes execution. Export <name> <value> Set the environment variable <name> equal to <value> in the global environment. Ifup <interface> Bring the network interface <interface> online. Import <filename> Parse and init config file, extending the current configuration. Hostname <name> Set the host name Chdir <directory> Change working directory Chmod <octal-dmoe> <path> Change file access permissions Chwon <owner> <group> <path> Change file owner and group Chroot <directory> Change process root directory Class_start <serviceclass> Start all services of the specified class if they are not already running. Class_stop <serviceclass> Stop all services of the specified class if they are currently running. Domainname <name> Set the domain name Enable <servicename> Turns a disabled service into an enabled one. Insmod <path> Install the module at <path> Mkdir <path> Create a directory at <path> Mount <type><device><dir> Attempt to mount the named device at the directory. Restorecon <path> Restore the file named by <path> to the security context specified in the file_contexts configuration. Setcon <securitycontext> set the current process security context to the specified string. Setenforce 0|1 Set the SELinux system wide enforcing status. 0 = permissive. 1 = enforcing. Setprop <name><value> Set system property <name> to <value> Setrlimit <resource><cur><max> Set the rlimit for a resource Setsebool <name><value> Set SELinux Boolean <name> to <value> Start <service> Start a service Stop <service> Stop a service Symlink <target><path> Create a symbolic link at <path> with the value <target> Trigger <event> Trigger an event. Used to queue an action from another action Wait <path> Poll for the existence of the given file and return when found. Write <path> <string> Open the file at <path> and write a string to it. Examples How to run a script: service my_service /data/test   class main   oneshot Here we are declaring the service named 'my service' with location in /data/test. It belongs to the main class and will start along with any other service that belongs with that class and we declare that the service wont restart when it exits (oneshot). Change file access permissions: chmod 0660   /sys/fs/cgroup/memory/tasks Here we are changing access permissions in path /sys/fs/cgroup/memory/tasks Write a string to a file in a path: write  /sys/fs/cgroup/memory/memory/memory.move_charge_at_immigrate   1 Create a symbolic link: symlink  /system/etc /etc Here we are creating a symbolic link to /system/etc -> /etc Set a specific density of the display: setprop ro.sf.lcd_density 240 Here we are setting a system property of 240 to ro.sf.lcd_density Set your watchdog timer to 30 seconds: service watchdog /sbin/watchdogd 10 20 class core We are petting the watchdog every 10 seconds to get a 20 second margin Change file owner: chown root system /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq The new owner being 'root' from the group 'system'