uboot and linux kernel deüelop process on zedboard

1 sudo gedit /etc/bash.bashrc and insert
    "export ARCH=arm"
    "export CROSS_COMPILE=arm-xilinx-linux-gnueabi-"
      and then run "source /etc/bash.bashrc" to make it work;
2 building the u-boot
    cd to dir "u-boot-xlnx",run"make ARCH=arm zynq_zed"
    add PATH: export PATH=/home/ubuntu/openhw/u-boot-xlnx/tools:$PATH
2 building the linux kernel;
    cd to linux-audio_zynq dir;
    run "make zync_xcomm_adv7511_defconfig" to get .config file;
    gedit ./config,make it"#CONFIG_XILINX_FIXED_DEVTREE_ADDR is not set"
    run "make uImage LOADADDR=0x8000"

3  when boot ,wo need to run "'fatload mmc 0 0x3000000 uImage && fatload mmc 0 0x2A00000 devicetree.dtb && bootm 0x3000000 - 0x2A00000'" in the serail;

4  how to autoboot:
    modify the zynq_commoc.h,the
    "sdboot=echo Copying Linux from SD to RAM... && " \
        "mmcinfo && " \
        "fatload mmc 0 0x3000000 ${kernel_image} && " \
        "fatload mmc 0 0x2A00000 ${devicetree_image} && " \
        "fatload mmc 0 0x2000000 ${ramdisk_image} && " \
        "bootm 0x3000000 0x2000000 0x2A00000\0" \

     to
        "sdboot=echo Copying Linux from SD to RAM... && " \
        "mmcinfo && " \
        "fatload mmc 0 0x3000000 uImage && " \
        "fatload mmc 0 0x2A00000 devicetree.dtb && " \
        "bootm 0x3000000 - 0x2A00000\0" \
    modify :
        #define CONFIG_BOOTCOMMAND    "${modeboot}"
    to
        #define CONFIG_BOOTCOMMAND    "run sdboot"