Guide
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How To Compile uboot:

1. select a reg file
        cd lowlevel_reg_info/
        cp hi3716cdmoverb_reg_info.reg ../.reg
    The file "hi3716cdmoverb_reg_info.reg" is the reg file for board hi3716c,
    you should select a reg file according to your dema board.

2. compile uboot
        make ARCH=arm CROSS_COMPILE=arm-xxx-linux- godbox -j 128
    The "fastboot-burn.bin" is the last image file to be downloaded to board.

3. compile mini-boot
        make xxxx mini-boot.bin
        make xxxx mini-boot.clean
    you are compile mini-boot after compile fastboot-burn.bin
    the mini-boot use lzma to compress fastboot-burn.bin.
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About Compile option:

1. Compile uboot with option
        make ARCH=arm CROSS_COMPILE=arm-xxx-linux- godbox [OPTION=VALUE]
    Example:
        make ARCH=arm CROSS_COMPILE=arm-xxx-linux- godbox \
            HISFV_PHY_U=1 HISFV_PHY_D=3

2. compile options:

    HISFV_PHY_U
        Up port eth phy id
        Example:
            make xxxx HISFV_PHY_U=1

    HISFV_PHY_D
        Up port eth phy id
        Example:
            make xxxx HISFV_PHY_D=3

    CONFIG_SUPPORT_CA
        Support advance ca, no define means NOT support advance ca.
        The ca define as follow, left define used in source, right define
        used in Makefile
            CONFIG_SUPPORT_CA_NAGRA    "NAGRA"
            CONFIG_SUPPORT_CA_CONAX    "CONAX"
            CONFIG_SUPPORT_CA_NOVEL    "NOVEL"
            CONFIG_SUPPORT_CA_SUMA     "SUMA"
            CONFIG_SUPPORT_CA_CTI      "CTI"
            CONFIG_SUPPORT_CA_OTHER    "OTHER"

        Make parameter as follow:
            make xxxx CONFIG_SUPPORT_CA="NAGRA"    // used nagra ca
            make xxxx CONFIG_SUPPORT_CA="OTHER"    // used other ca
            make xxxx                              // NOT support ca
            make xxxx CONFIG_SUPPORT_CA=""         // NOT support ca

        In source code:
            #if defined(CONFIG_SUPPORT_CA_NAGRA)
            // Do nagra ca code
            #elif defined(CONFIG_SUPPORT_CA_OTHER)
            // Do other ca code
            #endif

            #ifdef CONFIG_SUPPORT_CA
            // Do support ca code
            #else
            // Do NOT support ca code
            #endif

    CONFIG_SUPPORT_CA_RELEASE
        support release in ca config

    CONFIG_SUPPORT_CA_DEBUG
        support debug in ca config

    CONFIG_SDKVERSION
        fastboot support a sdk version, the version can pass to kernel.
            make xxxx CONFIG_SDKVERSION="0.1.0.0"

    CONFIG_WITH_PRODUCT
        Compile without product directory.
            make xxxx CONFIG_WITH_PRODUCT=""
        Compile with product directory.
            make xxxx CONFIG_WITH_PRODUCT="y"

    CONFIG_DDR_TRAINING
        Enable ddr training 

    CONFIG_FORCE_ENV_IN_NAND
    CONFIG_FORCE_ENV_IN_SPI
    CONFIG_FORCE_ENV_IN_EMMC
        If not defined, environment value will save in startup media;
        if define CONFIG_FORCE_ENV_IN_NAND/CONFIG_FORCE_ENV_IN_SPI
        /CONFIG_FORCE_ENV_IN_EMMC, environment will force save in NAND/SPIFlash/eMMC.

    CONFIG_SHOW_RESERVE_MEM_LAYOUT
        Show reserve memory layout

    CONFIG_MERGE_IMAGE
        this image will merge to fastboot-burn.bin, and use command "run" to run it.
            make xxxx CONFIG_MERGE_IMAGE=merge.img
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Configure options

    define or undefine this config file "include/configs/godbox.h"

CONFIG_CMD_USB
    Support usb ohci driver.

CONFIG_CMD_FAT
    Support vfat filesystem, this config should include CONFIG_CMD_USB first.
    some operation command as follow:
        usb start
        fatls usb 0
        fatload usb 0 0x82000000 kernel.img

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u-boot debug command
    the follow command is used in debug.

        setenv phyaddrup   1  // set ethernet up port phy address 1
        setenv phyaddrdown 3  // set ethernet down port phy address 3

    Set ethernet phy addr, kernel and u-boot will use the phy addr.
    If not set the value, u-boot will use marco "HISFV_PHY_U" and
    "HISFV_PHY_D" as default value, and pass it to kernel.

        setenv ethact down  // tftp file use ethernet down port 
        setenv ethact up    // tftp file use ethernet up port

    Set u-boot ethernet active port. this command only affect u-boot.
    It will designate the ethernet port which we use transmit data by tftp.
    If not set the value, u-boot will loop check which port is active, and
    use the first active port. even if the port have not connect to a
    tftp-server.

       setenv unddrtr y // forbid boot ddr training.

    Default config ddr training is enableed,