The Linux Kernel is just another recipe for Yocto, so learning to patch it you learn to patch any other package. In the other hand, Yocto **should not** be used for package development, but in those rare cases follow the below steps. It is assumed that you have already build the package you want to patch. 1. Create the patch or patches. In this example we are patching the Linux kernel for [wandboard-dual](http://www.wandboard.org/) machine; in other words, the value of MACHINE on the `build/conf/local.conf` is `MACHINE ??= 'wandboard-dual'`. In case you already have the patches, make sure these can be nicely applied with the commands `git apply --check <PATCH_NAME>`, and jump this step build $ cd tmp/work/wandboard_dual-poky-linux-gnueabi/linux-wandboard/3.0.35-r0/git build $ # Edit any files you want to change build $ git add <modified file 1> <modified file 2> .. # Select the files you want to commit build $ git commit -s -m '<your commit's title>' # Create the commit build $ git format-patch -1 # Create the patch 2. Create a new layer (see document i.MX Yocto Proyect: How can I create a new Layer?) 3. On the new layer (e.g `meta-fsl-custom`) , create the corresponding subfolders and the `.bbfile` sources $ mkdir -p meta-fsl-custom/recipes-kernel/linux/linux-wandboard-3.0.35/ sources $ cat > meta-fsl-custom/recipes-kernel/linux/linux-wandboard_3.0.35.bbappend FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:" SRC_URI += "file://0001-calibrate-Add-printk-example.patch" PRINC := "${@int(PRINC) + 1}" # SEE NOTE BELLOW ^d (The PRINC variable is not needed starting at Yocto 1.6 ([RFC] base.bbclass: Deprecate the PRINC logic - Patchwork)) 4. Move the patch to the new layer sources $ cp \ ../build/tmp/work/wandboard_dual-poky-linux-gnueabi/linux-wandboard/3.0.35-r0/git/0001-calibrate-Add-printk-example.patch \ meta-fsl-custom/recipes-kernel/linux/linux-wandboard-3.0.35 5. Setup the enviroment and clean previous package's build data (sstate) fsl-community-bsp $ . setup-environment build build $ bitbake -c cleansstate linux-wandboard 6. Compile and Deploy build $ bitbake -f -c compile linux-wandboard build $ bitbake -c deploy linux-wandboard 7. Insert the SD into your Host and copy the `uImage` into the first partition. Do not forget to unmount the partition before removing the card! build $ sudo cp tmp/deploy/images/uImage /media/Boot\ wandbo/ 8. Insert the SD into your board and test your change.

bitbaked meta-toolchain-qt Install it  with ~/yocto/build/tmp/deploy/sdk$ poky-eglibc-x86_64-arm-toolchain-qt-1.4.1.sh Download Qtcreator from here http://qt-project.org/downloads and Install it to Your home directory edit the bin/qtcreator.sh source /opt/poky/1.4.1/environment-setup-armv7a-vfp-neon-poky-linux-gnueabi #! /bin/sh makeAbsolute() {     case $1 in         /*)             # already absolute, return it             echo "$1"             ;;         *)             # relative, prepend $2 made absolute             echo `makeAbsolute "$2" "$PWD"`/"$1" | sed 's,/\.$,,'             ;;     esac } .... To do it before "#! /bin/sh" is IMPORTANT!!!! In QtCreator i set Compiler as                /opt/poky/1.4.1/sysroots/x86_64-pokysdk-linux/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi/arm-poky-linux-gnueabi-g++ Qt version as                               /opt/poky/1.4.1/sysroots/x86_64-pokysdk-linux/usr/bin/qmake sysroot as                     /opt/poky/1.4.1/sysroots/armv7a-vfp-neon-poky-linux-gnueabi Put them in a Kit For connection to Your Board click on  Device  --->    Manage Build a new project and add some to the .pro file Building the image for Your Board: add         EXTRA_IMAGE_FEATURES = "debug-tweaks ssh-server-openssh" to Your localconfig bitbake core-image-sato-sdk set a password to root  via ssh root@[boardip] passwd test connection via sftp  root@[boardip] start qtcreator ./qtcreator.sh Message was edited by: Joerg Boge Good Video to get more Information about Programming are this Beaglebone: LCD Touchscreen GUI Applications for Embedded Linux - YouTube Beaglebone: Qt Creator for C++ ARM Embedded Linux Development - YouTube Beaglebone: Example Qt Embedded Linux Application - YouTube It is for Beagelbone but for programming Qt it is a good start. Dieses Dokument wurde aus folgender Diskussion erzeugt: Setup QT Creator with Yocto Build

After bitbake meta-toolchain the script to install the toolchain package is located under $ ls tmp/deploy/sdk/poky-eglibc-x86_64-arm-toolchain-1.4.1.sh    tmp/deploy/sdk/poky-eglibc-x86_64-arm-toolchain-1.4.1.sh In order to install it: $ source poky-eglibc-x86_64-arm-toolchain-1.4.1.sh     [sudo] password for daiane:     Enter target directory for SDK (default: /opt/poky/1.4.1):     You are about to install the SDK to "/opt/poky/1.4.1". Proceed[Y/n]?y     Extracting SDK...done     Setting it up...done     SDK has been successfully set up and is ready to be used. Hello World $ source /opt/poky/1.4.1/environment-setup-armv7a-vfp-neon-poky-linux-gnueabi $ cd ~/test/ $ arm-poky-linux-gnueabi-gcc helloworld.c $ ls a.out                                                 helloworld.c                           $ ./a.out -bash: ./a.out: cannot execute binary file $ file a.out a.out: ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.16, not stripped Kernel $ source /opt/poky/1.4.1/environment-setup-armv7a-vfp-neon-poky-linux-gnueabi $ cd linux-2.6-imx $ git checkout remotes/origin/imx_3.0.35 $ export ARCH=arm $ export CROSS_COMPILE=$TARGET_PREFIX $ unset LDFLAGS $ make imx6_defconfig $ make uImage Make sure to have mkimage available on bin patch (if using mkimage from u-boot export its patch) Or, download the ubuntu pachage: sudo apt-get install uboot-mkimage UPDATE You may find the following error:   OBJCOPY arch/arm/boot/zImage   Kernel: arch/arm/boot/zImage is ready multiple (or no) load addresses: This is incompatible with uImages Specify LOADADDR on the commandline to build an uImage make[1]: *** [arch/arm/boot/uImage] Error 1 make: *** [uImage] Error 2 This is regarding a missing LOADADDR for mkimage to use to generate uImage with the right offset to be placed in the right LOADADDR. The address value is dependent on your hardware! And it is different depending on imx6 variations. So please be aware regarding what is your right value. If the machine you are using is supported in yocto project/meta-fsl-arm, for example, you can find the value related with your board in the file conf/machine/include/imx-base.inc or online here meta-fsl-arm - Layer containing Freescale ARM hardware support metadata It is the same value used in variable UBOOT_ENTRYPOINT. For example as of this writing for the Freescale SABRE-SD board looking in conf/machine/include/imx-base.inc UBOOT_ENTRYPOINT_mx6  = "0x10008000" Thus the build command would be: $ make uImage LOADADDR=0x10008000 So, as a quick reference table, I point here the 3 most wanted make command lines: imx28evk: $ make LOADADDR=0x40008000 imx53qsb: $ make LOADADDR=0x70008000 imx6qsabresd: $ make LOADADDR=0x10008000 Update 2 Suggested by cmcqueen1975 Building an autotools-based package. E.g. $ source /opt/poky/1.4.1/environment-setup-armv7a-vfp-neon-poky-linux-gnueabi $ ./configure ${CONFIGURE_FLAGS} $ make $ make install the CONFIGURE_FLAGS is the variable depending on your very-own project. Go to Yocto Training - HOME Go to Task #7 - Create the toolchain

Qt framework Qt is a cross-platform complete development framework with tools designed to streamline the creation of stunning native applications and amazing user interfaces for desktop, embedded and mobile platforms. Qt's cross-platform full framework and tools enables developers to target various desktop, embedded, mobile and real-time operating systems with one code base. Qt brings freedom to the developer saving development time, adding efficiency and ultimately shortening time to market. Building Qt Compile Qt for i.MX28 Building QT5 for i.MX53 Building QT for i.MX6 Qt on iMX6 Installing tools Installing and Configuring QT Creator (Ubuntu) Qt5 with Qt3D over Wayland rootfs Demos Qt5 Cinematic Experience Demo on i.MX6 Video - IMx 53 Qt5 qt3d demo Qt5 with Qt3D over Wayland rootfs Information Qt5 on i.MX6  DO's and DONT's Best Practices for QML

Hi,      Here share the hardfloat rootfs making document and related pkgs, please feel free for download best regards Jack

Step 1: Build r13.4.1         make         /* Store images file for MFGTool use */         make dist    /* Get ota_1.zip, and target_files_1.zip at out/dist, store them in a dedicated directory, for example .../release-1 */ Step 2: Modify any files in source code base; Step 3: make dist    /* Get ota_2.zip, and target_files_2.zip at out/dist, store them in a dedicated directory, for example .../release-2 */ Step 4: MFGTool flash release-1 images; Step 5: cp ota_2.zip to SD; Step 6: start board, then execute following commands under serial terminal;         cp /sdcard/ota_2.zip /cache/ota_2.zip         mkdir /cache/recovery         echo --update_package=/cache/ota_2.zip > /cache/recovery/command         sync         reboot recovery         Then you can see the upgrade successful. Step 7: MFGTool flash release-1 images; Step 8: ./build/tools/releasetools/ota_from_target_files -i .../release-1/target_files_1.zip .../release-2/target_files_2.zip ./diff_from_1_to_2.zip Step 9: cp diff_from_1_to_2.zip to SD; Step10: start board, then execute following commands under serial terminal;         cp /sdcard/diff_from_1_to_2.zip /cache/diff.zip         mkdir /cache/recovery         echo --update_package=/cache/diff.zip > /cache/recovery/command         sync         reboot recovery

    Attached is the SDHC DMA read supported patch, it is based on WCE600_MX51_ER_1104, it was verified on iMX51 EVK board. The SDHC DMA read can reduce the NK copy time, in this way it can speed up the WinCE boot.

We use PCIe to connect Intersil TW6865 chip for the surround view solution. This is the connection of PCIe to iMX6Q SabreSD board.   This is the block diagram of the connection: This is the 4 camera surround view:   Code base is L3.0.35_12.10.02 release. You can merge the patch file to the latest Freescale release. Please check the attach file for the patch code.   Note:  It is only a test version. The last code for L3.0.35 BSP: L3.0.35_GA4.1.0 Patches.7z The last code for L3.10.53 BSP: L3.10.53_TW686x_patch.7z Patch for L4.1.15 1.1.0 GA BSP: TW6865 driver for Linux L4.1.15_1.1.0-ga.7z

When a board is brought up and  the ddr test by link of "https://community.nxp.com/docs/DOC-96412' hashttps://community.nxp.com/docs/DOC-96412' hashttps://community.freescale.com/docs/DOC-96412' hashttps://community.nxp.com/docs/DOC-96412' has been verified, some of boards will have pfd issue(ERR006282). It is suggested that below method could be used to check the issue.The detail steps are: As boards may have no jtag port, the internal usdhc4 root clock out needs to be remapped. When “CUP not initialized” issue has been seen and in download mode, DDR test tools can be used with the script to remap clock output. Please check the attached for test script and the empty the binary. Put the two files to DDR stress test tool folder “DDR_Stress_Tester\binary\”. The attached ddr-stress-test-mx6dq.bin is an empty file. Please backup the original file first. After eMMC boot failed and in download mode, run command “DDR_Stress_Tester.exe -t mx6x -df test.inc” on PC side. There is no clock output on GPIO19. For normal test, please erase the eMMC chip and boot the board. It will also fail to boot and run into download mode. After run “DDR_Stress_Tester.exe -t mx6x -df test.inc” , clock can be measured from GPIO19 if no PDF issue happens. Below is  the details: The script file. wait = on A: Config GPIO19(ENET_ RST_ PHY_B) as CLKO1 setmem /32 0x020E0254 = 0x3    // Config GPIO19(ENET_ RST_ PHY_B) as CLKO1      On your board, it is R112 for the test point. B: enabled, CKO1 output drives cko2 clock, divide by 5, usdhc4_clk_root setmem /32 0x020C4060 = 0x01820101  // CKO2 enabled, CKO1 output drives cko2 clock, divide by 5, usdhc4_clk_root Hex 0 1 8 2 0 1 0 1 Bits 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Binary 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 And for the normal boot, erase the emmc, and reboot to enter the download mode. There will be no signal output but high voltage on R112. After the script runs, 40Mhz clock will be seen. For the boot fail case, there will be no signal output but high voltage on R112 and 40Mhz clock will be pulled to low. 1: CKO2 enabled 2: divide by 5 3 usdhc4_clk_root 4: CKO1 output drives cko2 clock 5

ERR005723           PCIe: PCIe does not support L2 Power Down   Description: When PCIe works as Root Complex, it can exit L2 mode only through reset. Since PCIe doesn't have a dedicated reset control bit, it cannot exit L2 mode.   Projected Impact: PCIe does not support L2 Power Down   Workarounds: The PCIe can be put in PDDQ mode to save on PCIe PHY power and wakeup only by the OOB (Out of Band) wakeup signal (since wakeup by a beacon from link partner is not supported) driven from the link partner (End Point). This signal could be used as a GPIO interrupt to exit this mode. The limitation of this workaround is that the link partner cannot be put into L2.   Proposed Solution:                 No fix scheduled   Linux BSP Status:                 No software workaround available   SW workaround used to fix ERR005723 in Linux BSP Why the original workarounds can’t be implemented in Linux BSP * PCIe controller doesn’t have the reset mechanism that can be used when re-insmod the PCIe driver without power down/up PCIe module. * During the PCie driver rmmod/insmod operations, the PCIe CLKs would be turned off/on. IC can’t guarantee that the PCIe PHY can work well and re-establish the PCIe link properly. One SIMPLE SW workaround for this errata imx: pcie: toggle bit18 of grp1 fix pcie can't exit L2 issue.   Set bit18 of gpr1 before enter into supend, and clean it after resume, can fix the following errata. Errata ERR005723_PCIe PCIe does not support L2 Power Down. About the details, please refer to the attached patch. "0001-imx-pcie-toggle-bit18-of-grp1-fix-pcie-can-t-exit-L2.patch"   The conception of the other SW workaround (System warm-reset) The procedures of the original suspend/resume. Suspend User suspend command echo mem > /sys/power/state All driver call suspend function SRPG,  ARM save all state to memory Enter Stop mode and Power down ARM Resume: GPC receive IRQ Wake up system Power on ARM domain. ROM code running Jump to SRPG point Recovery ARM status from memory Call all devices resume function. Because PCIe only reset by system reset, we need change above follow. Resume: GPC receive IRQ Wake up system Power on ARM domain. ROM code running Jump to SRPG point Warm Reset system, memory context will be kept. But all peripheral status lost. ROM code running Jump to SRPG point again. Recovery ARM status from memory Call all devices resume function. Resume function call init to initialize it.  And recover to the status saved before. Impact: Can’t support usb remote wake up, which required 4ms responsive Longer latency, warm reset need some ms.  The recovery of the device status needs some more ms. Risk: Current BSP have not tested above follow Device driver have not supported this follow yet. Need additional work to enable \debug\test it. Modules enabled in this workaround now: * UART* ENET* PCIe Tests procedure. HW: one i.MX6Q SD boards, and one INTEL pciex1 1000M CT network card. SW(The images used by me are attached): * Apply the attached patches(kernel and uboot) to the kernel/uboot source codes, re-build, get the images. Kernel is based on imx_3.0.35_4.0 release, uboot , is based on imx_v2009.08 # build out SD/MMC and USB driver to make DRAM hibernate work # build pcie in. *procedure of the suspend/resume tests;     # unload ep's driver --> suspend/resume --> reload ep's driver. NOTE: Please make sure that the command line contains “no_console_suspend”The command used to enable the console input wake up after login the consol:echo enabled > /sys/devices/platform/imx-uart.0/tty/ttymxc0/power/wakeup Log when the INTEL CT 1G network card is used: -------------------------------log--------------------------------------------PM: Syncing filesystems ... done.                                             start suspendFreezing user space processes ... (elapsed 0.01 seconds) done.Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.add wake up source irq 101add wake up source irq 99add wake up source irq 103add wake up source irq 51add wake up source irq 58PM: suspend of devices complete after 15.482 msecsPM: late suspend of devices complete after 0.823 msecsDisabling non-boot CPUs ...CPU1: shutdownCPU2: shutdownCPU3: shutdownIMX PCIe imx_pcie_pltfm_suspend entering.IMX PCIe imx_pcie_pltfm_suspend exit.          suspendedU-Boot 2009.08-00679-g6ec6783 (May 20 2013 - 14:50:20)     resumeCPU: Freescale i.MX6 family TO1.2 at 792 MHzsrc 0x92eac8resume 0x92eac8jump to resumeIMX PCIe imx_pcie_pltfm_resume entering.IMX PCIe imx_pcie_pltfm_resume pcie start re-link.IMX PCIe port imx_pcie_pltfm_resume: re-link up.Enabling non-boot CPUs ...CPU1: Booted secondary processorCalibrating delay loop (skipped) already calibrated this CPU i.MXC CPU frequency driver CPU1 is upCPU2: Booted secondary processorCalibrating delay loop (skipped) already calibrated this CPU i.MXC CPU frequency driver CPU2 is upCPU3: Booted secondary processorCalibrating delay loop (skipped) already calibrated this CPU i.MXC CPU frequency driver CPU3 is up PM: early resume of devices complete after 0.974 msecs remove wake up source irq 58 imx-ipuv3 imx-ipuv3.0: IPU DMFC DP HIGH RESOLUTION: 1(0,1), 5B(2~5), 5F(6,7) imx-ipuv3 imx-ipuv3.1: IPU DMFC DP HIGH RESOLUTION: 1(0,1), 5B(2~5), 5F(6,7) remove wake up source irq 51 remove wake up source irq 103 remove wake up source irq 101 remove wake up source irq 99 PM: resume of devices complete after 54.174 msecs Restarting tasks ... done. PHY: 1:01 - Link is Up - 100/Full                            resume is ok, reload ep’s driver num is 61 e1000e: Intel(R) PRO/1000 Network Driver - 1.3.10-k2 e1000e: Copyright(c) 1999 - 2011 Intel Corporation. e1000e 0000:01:00.0: Disabling ASPM L0s e1000e 0000:01:00.0: (unregistered net_device): Failed to initialize MSI-X interrupts.  Falling back to MSI interrupts. e1000e 0000:01:00.0: (unregistered net_device): Failed to initialize MSI interrupts.  Falling back to legacy interrupts. e1000e 0000:01:00.0: eth1: (PCI Express:2.5GT/s:Width x1) 00:1b:21:3a:18:8b e1000e 0000:01:00.0: eth1: Intel(R) PRO/1000 Network Connection e1000e 0000:01:00.0: eth1: MAC: 3, PHY: 8, PBA No: E42641-005 e1000e: eth1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx PING 192.168.0.1 (192.168.0.1): 56 data bytes 64 bytes from 192.168.0.1: seq=0 ttl=64 time=3.126 ms 64 bytes from 192.168.0.1: seq=1 ttl=64 time=0.244 ms 64 bytes from 192.168.0.1: seq=2 ttl=64 time=0.232 ms 64 bytes from 192.168.0.1: seq=3 ttl=64 time=0.206 ms 64 bytes from 192.168.0.1: seq=4 ttl=64 time=0.222 ms 64 bytes from 192.168.0.1: seq=5 ttl=64 time=0.207 ms 64 bytes from 192.168.0.1: seq=6 ttl=64 time=0.250 ms 64 bytes from 192.168.0.1: seq=7 ttl=64 time=0.209 ms 64 bytes from 192.168.0.1: seq=8 ttl=64 time=0.154 ms 64 bytes from 192.168.0.1: seq=9 ttl=64 time=0.211 ms   --- 192.168.0.1 ping statistics --- 10 packets transmitted, 10 packets received, 0% packet loss round-trip min/avg/max = 0.154/0.506/3.126 ms PM: Syncing filesystems ... done.                                   ep’s functions are ok, re-do the suspend/resume tests Freezing user space processes ... (elapsed 0.01 seconds) done. -------------------------------end-------------------------------------------- Original Attachment has been moved to: uboot_patch_image.zip Original Attachment has been moved to: 0001-imx-pcie-toggle-bit18-of-grp1-fix-pcie-can-t-exit-L2.patch.zip Original Attachment has been moved to: kernel_patch_image.zip

Build the tool chain image. It generates the toolchain that will be installed on your host machine and used to build any source code: $ bitbake meta-toolchain It does take some time to build. Why to create a toolchain? Yocto is not intended to be used to package development. Yocto is a linux distribution creator. It´s intended to be a image builder, a rootfs creator. (please, see more about "what is yocto" here and here) So, yocto itself should not be used to "develop" a new package. Although, Yocto can help creating a environment for development like meta-toolchain or Eclipse ADT. Go HOME Go Task #6 - Customize the image

A tutorial on 'Freescale Yocto Project'. Source code is located here NOTE: When doing 'repo init -u .... -b <LATEST_STABLE_BRANCH_NAME>', make sure you are using the latest stable branch (dora is the latest when writing this note)

    Some customer will use NAND flash as the storage device, also in auto application field,  the fast boot is also necessary,  so how to make the read speed faster is a question. FSL provide some patches for fast boot, they’re also suitable for NAND fast boot. These patch mainly enable the MMU and SDMA in uboot, some part of the patches is special for MMC.        0001-Merge-from-12.0.4-fastboot.patch     0002-Add-fsclmmcdma-code.patch    Some NAND flash support the EDO feature, according to the device feature mode, the NAND flash can be set different clock frequency.  Here will describe how to calculate the NAND working clock.    The NAND clock is divider from the GPMI source clock, can be program in setup_gpmi_nand().  The  divider was configured in register GPMI_TIMING0, the NAND clock can get from the following:           NANDCLK=GPMICLK/(DATA_HOLD+DATA_SETUP)    NAND Clock will affect the speed a lot, for the NAND chipsets which support the EDO, the nand speed will be set automatically. For those doesn’t support EDO NAND chip, the usr should take care those setting manually. There is also a patch for enable EDO mode and set NAND clock automatically.               0008-NAND-configure-as-EDO-mode-5.patch     Besides above, there are two other patches to improve the speed about 30%, 0009-For-nand-page-align-read-include-read-offset-and-siz.patch enabled the cache read(Note: please make sure the NAND chipset support cache read), it will reduce the unnecessary command transfer between the CPU and NAND, 0010-If-possible-directly-use-user-buffer-as-BCH-nand-buf.patch remove some unnecessary memcpy.

The solution works when I use mx53_loco bsp. Modify u-boot and kernel, keep the same. Then you may find you can't login into the system regardless of whatever you input after freescale login: It confused me for a long time. If you  also met this problem,try to check the iomux-mx53.h(linux/arch/arm/plat-mxc/include/mach/). #define _MX53_PAD_PATA_DIOW__UART1_TXD_MUX   IOMUX_PAD(the fourth argument 0x878 should be changed to 0x0) I think this is a small bug in header files. Haifeng

Don't forget to update your source code. How to customize the image Enter <yocto>/source and find any image available: $ find -name *image*.bb ./meta-fsl-demos/recipes-fsl/images/fsl-image-gui-sdk.bb ./meta-fsl-demos/recipes-fsl/images/fsl-image-test.bb ./meta-fsl-demos/recipes-fsl/images/fsl-image-gui.bb ./meta-fsl-demos/recipes-qt/images/qt-in-use-image.bb ./meta-fsl-demos/recipes-qt/images/qte-in-use-image.bb ./meta-openembedded/meta-initramfs/recipes-bsp/images/initramfs-kexecboot-klibc-image.bb ./meta-openembedded/meta-initramfs/recipes-bsp/images/initramfs-kexecboot-image.bb ./meta-openembedded/meta-oe/recipes-support/imagemagick/imagemagick_6.7.5.bb ./meta-openembedded/meta-oe/recipes-multimedia/libsdl-image/libsdl-image_1.2.12.bb ./poky/meta-hob/recipes-core/images/hob-image.bb ./poky/meta-skeleton/recipes-multilib/images/core-image-multilib-example.bb ./poky/meta/recipes-devtools/mkelfimage/mkelfimage_svn.bb ./poky/meta/recipes-sato/images/core-image-sato-dev.bb ./poky/meta/recipes-sato/images/core-image-sato.bb ./poky/meta/recipes-sato/images/core-image-sato-sdk.bb ./poky/meta/recipes-qt/images/qt4e-demo-image.bb ./poky/meta/recipes-core/images/core-image-minimal.bb ./poky/meta/recipes-core/images/core-image-base.bb ./poky/meta/recipes-core/images/core-image-minimal-dev.bb ./poky/meta/recipes-core/images/core-image-minimal-initramfs.bb ./poky/meta/recipes-core/images/build-appliance-image.bb ./poky/meta/recipes-core/images/core-image-minimal-mtdutils.bb ./poky/meta/recipes-extended/images/core-image-lsb-sdk.bb ./poky/meta/recipes-extended/images/core-image-basic.bb ./poky/meta/recipes-extended/images/core-image-lsb-dev.bb ./poky/meta/recipes-extended/images/core-image-lsb.bb ./poky/meta/recipes-graphics/images/core-image-directfb.bb ./poky/meta/recipes-graphics/images/core-image-x11.bb ./poky/meta/recipes-graphics/images/core-image-clutter.bb ./poky/meta/recipes-graphics/xcb/xcb-util-image_0.3.9.bb ./poky/meta/recipes-bsp/u-boot/u-boot-mkimage_2012.04.01.bb ./poky/meta/recipes-bsp/u-boot/u-boot-mkimage_2011.06.bb ./poky/meta/recipes-bsp/u-boot/u-boot-mkimage_2011.03.bb ./poky/meta/recipes-rt/images/core-image-rt-sdk.bb ./poky/meta/recipes-rt/images/core-image-rt.bb The above images (and packages with 'image' in file name) may be used as a base image, where new packages may be added, or example of new images. bitbake -s  shows any *available* package locally. Grep for the name of desired package: $ bitbake -s | grep calibrat calibrateproto                      :0.0+gitAUTOINC+1da6fd1e2c7a49648245c98481fabea8b9690a8c-r2             libxcalibrate                       :0.0+gitAUTOINC+209d83af61ed38a002c8096377deac292b3e396c-r0             xinput-calibrator                   :0.7.5+gitAUTOINC+c01c5af807cb4b0157b882ab07a893df9a810111-r1 For example, the package name is xinput-calibrator, in order to include this package this would be the string needed. The dependency tree is shown with $ bitbake -g fsl-image-test For the fsl-image-test. Or any other image Include the package name on the image definition file. $ cd meta-fsl-demos/ $ vim recipes-fsl/images/fsl-image-test.bb Include the package name on IMAGE_INSTALL list: IMAGE_INSTALL += " \     packagegroup-fsl-gstreamer \     packagegroup-fsl-tools-testapps \     packagegroup-fsl-tools-benchmark \ xinput-calibrator \ " In order to include the package on any image, configure conf/local.conf file the as the following: MACHINE ??= 'imx6qsabresd' DISTRO ?= 'poky' PACKAGE_CLASSES ?= "package_rpm" EXTRA_IMAGE_FEATURES = "debug-tweaks tools-sdk" USER_CLASSES ?= "buildstats image-mklibs image-prelink" PATCHRESOLVE = "noop" CONF_VERSION = "1" BB_NUMBER_THREADS = '8' PARALLEL_MAKE = '-j 8' ACCEPT_FSL_EULA = "1" CORE_IMAGE_EXTRA_INSTALL += "xinput-calibrator" And then $ bitbake fsl-image-test In order to add debug or native builder include on conf/local.conf: EXTRA_IMAGE_FEATURES += "tools-sdk" Every image created after that will include development tools. The same may be included in any bb image file. From Poky description: 'tools-sdk" - Adds development tools such as gcc, make, pkgconfig and so forth. "dev-pkg" - Adds -dev packages for all installed packages. This is useful if you want to develop against the libraries in the image. "tools-debug" - Adds debugging tools such as gdb and strace. If you don't like command line, or you prefer a window-like interface, you can take a look on HOB. See hob documentation https://www.yoctoproject.org/documentation/hob-manual See getting started video for hob Introducing Hob - YouTube Go to Yocto Training - HOME Go to Task #5 - Kernel

In this post we see how to setup a Debian server, to allow booting the i.MX6 sabre sd platform (mostly) from the network. Booting from the network instead of e.g. the SD card is very handy for day to day development and testing, as it eliminates almost all physical interactions with the board and saves much time. Also, fortunately for us, both u-boot and Linux for i.MX6 support network booting out of the box. Boot sequence principles Before we setup the server, here are some more details on the boot sequence we will obtain in the end: i.MX6 boots, loads u-boot from SD card. u-boot starts, loads its environment (boot commands) from SD card. u-boot obtains its network address by DHCP, loads a Linux kernel uImage and a dtb by TFTP. Linux boots; obtains its network address by DHCP (again), mounts its root filesystem on NFS. Setting up DHCP and TFTP One can easily setup a Debian server to act as DHCP and TFTP server with Dnsmasq; just install the dnsmasq package. The default configuration is mostly empty; so we need to enhance it a bit. For the following we will assume that your Debian server has IP address 192.168.111.1 on the network where it sees the i.MX6 sabre sd platform. You can add some options to a dnsmasq config file such as e.g. /etc/dnsmasq.d/my-custom-config-file:   dhcp-range=192.168.111.50,192.168.111.150,12h   enable-tftp   tftp-root=/var/ftpd This informs dnsmasq to act as a DHCP server for addresses range 192.168.111.50-150 and act as TFTP server, which serves files under /var/ftpd. That means you will need to copy a Linux uImage and an imx6q-sabresd.dtb under /var/ftpd/. See this post for more details about compiling Linux to obtain those two files. Setting up NFS If we want the root filesystem to be mounted on the network we will need to export some folders with NFS from the Debian server. We need to install the nfs-kernel-server package and setup /etc/exports with a line such as:   /tftpboot       192.168.111.*(rw,no_root_squash,subtree_check) This allows clients on the 192.168.111.0 network to access filesystems under the /tftpboot folder. So you will need to create a /tftpboot folder on the server, and install some "filesystem" under there. For this example we assume you will have a busybox installed under a /tftpboot/busybox/ folder. That means we want to have under there all folders such as bin, dev, etc... See this post for details on how to compile busybox to populate this folder. Do not forget to restart the NFS server after configuration, with:   # /etc/init.d/nfs-kernel-server restart We are now setup on the server side. Setting up u-boot At the time of this writing we need to help u-boot a bit when booting the i.MX6 sabre sd platform from the network. Stop at u-boot prompt and configure a few things:   env default -a   setenv netargs $netargs rw   setenv serverip 192.168.111.1   setenv nfsroot /tftpboot/busybox   setenv bootcmd run netboot   saveenv Reset your board; it should now boot from the network:   U-Boot 2013.07-rc1-00210-gc623eb0 (Jun 27 2013 - 21:10:47)   (..)   Hit any key to stop autoboot:  0   Booting from net ...   BOOTP broadcast 1   DHCP client bound to address 192.168.111.121   Using FEC device   TFTP from server 192.168.111.1; our IP address is 192.168.111.121   Filename 'uImage'.   Load address: 0x12000000   Loading: #################################################################            #################################################################            #################################################################            #################################################################            ##########################            4 MiB/s   done   Bytes transferred = 4185600 (3fde00 hex)   BOOTP broadcast 1   DHCP client bound to address 192.168.111.121   Using FEC device   TFTP from server 192.168.111.1; our IP address is 192.168.111.121   Filename 'imx6q-sabresd.dtb'.   Load address: 0x11000000   Loading: ##            2.7 MiB/s   done   Bytes transferred = 22818 (5922 hex)   ## Booting kernel from Legacy Image at 12000000 ...      Image Name:   Linux-3.10.0-rc7   (..)   Starting kernel ...   Booting Linux on physical CPU 0x0   Linux version 3.10.0-rc7 (jenkins@debian) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Tue Jun 25 08:28:31 CEST 2013   (..)   Kernel command line: console=ttymxc0,115200 root=/dev/nfs ip=dhcp nfsroot=192.168.111.1:/tftpboot/busybox,v3,tcp rw   (..)   fec 2188000.ethernet eth0: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=2188000.ethernet:01, irq=-1)   IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready   libphy: 2188000.ethernet:01 - Link is Up - 1000/Full   IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready   Sending DHCP requests ., OK   IP-Config: Got DHCP answer from 192.168.111.1, my address is 192.168.111.121   IP-Config: Complete:        device=eth0, hwaddr=00:04:9f:02:b7:fd, ipaddr=192.168.111.121, mask=255.255.255.0, gw=192.168.111.1        host=192.168.111.121, domain=, nis-domain=(none)        bootserver=192.168.111.1, rootserver=192.168.111.1, rootpath=        nameserver0=192.168.111.1   ALSA device list:     No soundcards found.   VFS: Mounted root (nfs filesystem) on device 0:11.   devtmpfs: mounted   Freeing unused kernel memory: 292K (806d5000 - 8071e000)   Please press Enter to activate this console. Enjoy! Bonus: updating u-boot by the network One last piece remains on the SD card: u-boot. If you do not want to move your SD card out of its slot any more, here is a method for you to update even u-boot from the network. You will need to copy u-boot.imx under /var/ftpd. See this post for details on how to compile u-boot and obtain u-boot.imx. Then, at u-boot prompt, do:   dhcp $loadaddr u-boot.imx   mmc dev 1   mmc write $loadaddr 2 600 This will download a new u-boot.imx from the network and flash it to your SD card; reboot your board and you are done. Note that we give 600 as the number of SD card blocks to write; this is a rough estimate of ~300KB, which should work in most of the cases as writing a bit "too much" blocks does not harm. If you are very picky, you can compute the exact number of blocks by dividing your u-boot.imx size by 512 and rounding it up. See also... Did you know that dnsmasq primary role is to be used to "relay" the DNS queries? A feature that come very handy when you want to let your i.MX6 platform "see" the internet.

In the old Android release R10.3.x for i.MX5x, I had followed the user guide instructions to install the USB driver and am able to setup the ADB connection successfully. Unfortunately, for the same PC, the ADB fails to detect my i.MX6SL EVK which is using R13.5. Updating the Android SDK tools cannot help. The reason is the new Android device is using a different USB VID from the old release. So, to solve this problem, we need to update the ADB configuration to scan for the new vendor ID. Below are the steps to update the ADB configuration for Windows PC. These steps (and the steps for Linux PC as well) can also be found in the R10,3.x user guide. 1. Run the SDK's tools to generate an ADB configure file: C:\Program Files\Android\android-sdk\tools> android.bat update adb 2. Modify the adb usb configure file to add the new vendor id 0x18d1. File: X:\Profile\<your account>\.android\adb_usb.ini # ANDROID 3RD PARTY USB VENDOR ID LIST -- DO NOT EDIT. # USE 'android update adb' TO GENERATE. # 1 USB VENDOR ID PER LINE. 0x15a2 0x18d1 3. Unpack the Freescale Android USB win driver "android_usb_fsl.zip" in your Android BSP release package. If you can't find this file in your current package, please get the R10.3.x release for i.MX5x and unpack it. 4. File "tetherxp.inf" in the unpacked "android_usb_fsl" may not be the updated one if the "android_usb_fsl.zip" is extracted from an old release. So, please overwrite the file "tetherxp.inf" in unpacked "android_usb_fsl.zip" by the new "tetherxp.inf" in your current Android BSP release. 5. Enable the "USB debugging" option on the i.MX6 device System settings -> Developer options -> USB debugging 6. Connect the Android Device into PC, uninstall your old driver named "Android Phone" in the device manager, then re-install driver by scanning and locating .inf file under the directory you unpack the android_usb_fsl.zip manually. 7. Restart the ADB server C:\Program Files\Android\android-sdk\platform-tools> adb kill-server C:\Program Files\Android\android-sdk\platform-tools> adb start-server 8. Finally, test your ADB connection C:\Program Files\Android\android-sdk\platform-tools> adb devices List of devices attached 0123456789ABCDEF     device Congratulations! Your ADB is now working. If you have additional information about this topic, please feel free to comment. This document was generated from the following discussion: i.MX6: Android connect to ADB

Here we show how to generate a minimal root filesystem fairly quickly with BusyBox, for the i.MX6 sabre sd platform. 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. This implies you already have a "working" Linux development environment with some ARM cross-compilers at hand (e.g. Debian + Emdebian). busybox is so small that we will go for a ramdisk as our main root filesystem. Get busybox sources We will use git to fetch busybox sources:   $ git clone git://git.busybox.net/busybox This should create a busybox directory with all the latest sources. Note that for more stability you might want to checkout a release instead of the latest version; to do so, list the available release tags with e.g. git tag -l, and git checkout <the-desired-tag>. Compile Assuming your cross compiler is called e.g. arm-linux-gnueabihf-gcc, you can compile by doing:   $ cd busybox   $ export ARCH=arm   $ export CROSS_COMPILE=arm-linux-gnueabihf-   $ make defconfig   $ sed -i.orig 's/^#.*CONFIG_STATIC.*/CONFIG_STATIC=y/' .config   $ make   $ make install This should create an _install folder hierarchy containing binaries and links. Note that we force the build of a static binary with the sed command. Configure the root filesystem We need to add some more configuration into the _install folder before we can call it a minimal filesystem. Create some folders We need to create some mountpoints and folders:   $ mkdir _install/dev   $ mkdir _install/proc   $ mkdir _install/sys   $ mkdir -p _install/etc/init.d Add some configuration files and scripts We need to prepare the main init configuration file, _install/etc/inittab, with this contents:   ::sysinit:/etc/init.d/rcS   ::askfirst:/bin/sh   ::ctrlaltdel:/sbin/reboot   ::shutdown:/sbin/swapoff -a   ::shutdown:/bin/umount -a -r   ::restart:/sbin/init This is very close to the default behavior busybox init has with no inittab file. It just suppresses some warnings about missing tty. We need to add some more configuration to mount a few filesystems at boot for convenience. This is done with an _install/etc/fstab file containing:   proc     /proc proc     defaults 0 0   sysfs    /sys  sysfs    defaults 0 0   devtmpfs /dev  devtmpfs defaults 0 0 We also need to actually trigger the mount in the _install/etc/init.d/rcS script, which is called from the inittab. It should contain:   #!/bin/sh   mount -a And we need to make it executable:   $ chmod +x _install/etc/init.d/rcS Generate the ramdisk contents Now that we have adapted the root filesystem contents, we can generate a busybox ramdisk image for u-boot with the following commands:   $ (cd _install ; find |cpio -o -H newc |gzip -c > ../initramfs.cpio.gz)   $ mkimage -A arm -T ramdisk -d initramfs.cpio.gz uInitrd This results in a uInitrd file, suitable for u-boot. Prepare a boot script The default u-boot commands are not sufficient to boot our system, so we need to edit a boot.txt file with the following contents:   run loaduimage   run loadfdt   setenv rdaddr 0x13000000   fatload mmc ${mmcdev}:$mmcpart $rdaddr uInitrd   setenv bootargs console=${console},${baudrate} rdinit=/sbin/init   bootm $loadaddr $rdaddr $fdt_addr Then we generate a boot.scr script, which can be loaded by u-boot with:   $ mkimage -A arm -T script -d boot.txt boot.scr Put on SD card Assuming you have prepared your SD card with u-boot and Linux as explained in this post, you have a single FAT partition on your card with your kernel and dtb. Our boot script and ramdisk image should be copied alongside:   $ mount /dev/<your-sd-card-first-partition> /mnt   $ cp uInitrd boot.scr /mnt/   $ umount /mnt Your SD card first partition is typically something in /dev/sd<X>1 or /dev/mmcblk<X>p1. Note that you need write permissions on the SD card for the command to succeed, so you might need to su - as root, or use sudo, or do achmod a+w as root on the SD card device node to grant permissions to users. 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. Your busybox system should boot to a prompt:   ...   Freeing unused kernel memory: 292K (806d5000 - 8071e000)   Please press Enter to activate this console. After pressing enter you should have a functional busybox shell on the target. Enjoy! See also... For a more featured root filesystem you might want to try a Debian filesystem in a second SD card partition, as explained in this post, or generate your filesystem with Buildroot. If you plan to compile busybox often, you might want to use a C compiler cache; see this post.

You already know. Your source code is one week old now, so please, update it (or should I say 'sync' it?)! Get used to update your BSP layers. Recipe Is the name of file that determinates how a package should act. For example, the version, where it is the mainstream repo, how to build, install, link. etc. Kernel For meta-fsl-arm the kernel recipes are under meta-fsl-arm/recipes-kernel/linux (take a look here meta-fsl-arm - Layer containing Freescale ARM hardware support metadata) For meta-fsl-arm, there are 3 kernel recipes: linux-fslc_3.8.bb  --> kernel mainline (from kernel.org) linux-imx_2.6.35.3.bb  --> kernel from FSL, for imx5x and imx28 linux-imx_3.0.35.bb --> kernel from FSL for imx6 Take the linux-imx for imx6 as an example meta-fsl-arm - Layer containing Freescale ARM hardware support metadata The recipe determinates: what´s the compatible machine for this linux version (mx6) what´s the commit ID for the head of this code (SRCREV) (MX6DL and MX6SL have different source code) what´s the patches for the mx6 boards (SRC_URI). In order to see where the source code is cloned from, you need to go to .inc file meta-fsl-arm - Layer containing Freescale ARM hardware support metadata SRC_URI = "git://git.freescale.com/imx/linux-2.6-imx.git \            file://defconfig \ " it´s from git.freescale.com. In addition, there is a defconfig file added on SRC_URI. There is a defconfig file for every board, on every Linux revision. Some defconfigs are shared for more than one board (for example, every mx6 board), and some Linux version are not compatible for some boards (for example, imx53 is only compatible with 2.6.35). During a bitbake linux-imx, a temp folder will be created under build/tmp/armv7-imx6....../linux-imx, with code from git, patches and defconfig. Then bitbake takes that defconfig and configure the kernel, built it, and deploy it. So, in order to change the kernel configuration (make menuconfig) you must replace your defconfig file from meta-fsl-arm/recipes-kernel/linux/linux-imx-3.0.35/mx6 How to change kernel configuration Create the new defconfig Copy it to meta-fsl-arm/recipes-kernel/linux/linux-imx-3.0.35/mx6 (or the right folder for your board/kernel) $ bitbake -c cleansstate linux-imx $ bitbake linux-imx (if you want only the kernel image) $ bitbake fsl-image-gui (if you want to generate a complete image using the new kernel) How to make menuconfig with yocto $ bitbake -c menuconfig linux-imx will generate a config file on tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.0.35-r33.10/git/.config The complete step by step to change the kernel configuration $ bitbake -c menuconfig linux-imx (change anything) $ cp tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.0.35-r33.10/git/.config ../sources/meta-fsl-arm/recipes-kernel/linux/linux-imx-3.0.35/mx6/defconfig $ bitbake -c cleansstate linux-imx $ bitbake fsl-image-gui The uImage will be under tmp/deploy/image In order to replace only uImage binary into one ready sdcard: $sudo cp tmp/deploy/image/uImage-imx6-XXX.bin /media/user/Boot imx6/uImage Kernel Mainline - kernel.org In order to use kernel mainline instead of linux-imx. Please add the following code to your conf/local.conf PREFERRED_PROVIDER_virtual/kernel = "linux-fslc" Make sure the desired board is supported by kernel.org. In order to take and build kernel mainline manually, please see https://community.freescale.com/docs/DOC-95017 Final points It´s not a simple task, I know. Yocto is not the best tool for use to develop and customize kernel during development stage. It is easier to use an external toolchain (bitbake meta-toolchain). Once the kernel development, or customization, is done, the changes can be integrated in the Yocto so it is managed for production use. I like to have a copy of kernel source code cloned on my machine directly from git.freescale.com, then I can re-configure it, rebuild it, apply some patches, make changes, and build it manually - any way I want it. So, I only change kernel using yocto when I know the bug and I know how to fix it, and I have the patch. (and this is the way I like to work) Although this is how to configure (and even patch) kernel (if you want to patch kernel, follow the example in the recipes) If you face any error, please, let me know. I tested the steps and it worked, but I´m using an Ubuntu machine, not a virtual machine (and I´m not sure how -c menuconfig will act in a virtual machine). Go to Yocto Training - HOME Go to Task #4 - Deploy and test

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.