X210 brush machine -- use markdown to try to write

The raw materials needed for the brush system: development board, serial data cable, USB data cable

首先检查开发板能否被PC识别，不能识别说明我们的开发板驱动需要重新更新下，能识别就不需要了。
将串口线和USB线都插好，配合SecureCRT都接好

**************** breaking uboot**********************

For the brushing of the linux+Qt system, we need to pay attention to the details:
First, understand a concept:
what is the system console? What is uboot console?

• System console: It is the interface after entering the system without pressing it during the countdown.

• uboot console: When you press the button on the countdown 3 2 1, you will enter uboot.

Note that we destroy uboot under the system console.

Secondly, we need to learn how to make SD card burn images. There are two kinds of SD cards.

• 1. Use Jiuding SD card tool to download files to SD card under Windows (convenient)
• 2. Use the dd command under linux

Secondly, if we need to destroy the uboot in the onboard inand, but there is a problem, we have different ways of destroying for different operating systems.

The way to destroy uboot is as follows:

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安卓的镜像：(再次注意破坏是在系统控制台下，不是uboot界面)
    先输入：busybox dd if=/dev/zero of=/dev/block/mmcblk0 bs=512 seek=1 count=1 conv=sync
        会出现：
            1+0 records in
            1+0 records out
    后输入：sync 

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linux镜像:
    先输入:busybox dd if=/dev/zero of=/dev/mmcblk0 bs=512 seek=1 count=1 conv=sync
        会出现：
            1+0 records in
            1+0 records out     
    后输入:sync

At this point, our destruction work is over. We shut down and restart the development board again, and it cannot be started. At this time, the SecureCRT serial port prompts SD checksum error—indicating that the destruction is successful.

******************** Burn new uboot, kernel and root filesystems ****

• We have to dial the DIP switch to EMMC

• Use Jiuding's SD_Fusing tool to burn the uboot specified by Mr. Zhu to the SD card.

• Then insert the SD card, boot again, interrupt the system operation, and enter the uboot interface.

• Use a fastboot command of a uboot, fastboot is also a tool on the PC, you can use the command line to burn our files. Mr. Zhu pointed out that when burning the linux+Qt system, the disk needs to be partitioned first, that is When entering uboot, enter: fdisk -c 0 and then enter: fastboot to let the development board enter fastboot mode

• We use the fastboot tool on the PC (which is a folder), go to the cmd command line, find this highlighted content directory, and enter: fastboot. That is, running the fastboot tool on the PC. This tool requires us to copy all the system files that need to be burned to the fastboot file (we use a linuxQT folder to talk about Qt's uboot, kernel, and root file system) and then put the command on the PC line, enter: fastboot devices to see if our development board has been detected by the fastboot tool.

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If it is detected, run the following code in turn to burn to inand:

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>>>烧录uboot：fastboot flash bootloader linuxQT/uboot.bin                  烧uboot
    等待uboot界面显示:okey

>>>烧录kernel：fastboot flash kernel linuxQT/zImage-qt                     烧linux kernel
    等待uboot界面显示:okey

>>>>烧录根文件系统：fastboot flash system linuxQT/rootfs_qt4.ext3           烧rootfs

When partition 'system' flashed appears on the development board or secureCRT, the programming is over.
At this point, shut down and restart, and Qt should be able to run successfully at this time.

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The above is the entire burning process of the operation. According to the reason, Qt can be run.

**************** Following is my personal problem ********************

If the system restarts all the time, or the development board shows that Qt is incomplete, it is not that there is a problem with our burning system steps, but there may be a problem with our uboot.bin file.
We need to use the print command to print out all the environment variables and check if the bootcmd and bootargs are the following values. If not, it is wrong and needs to be corrected.
Our uboot supports modifying the environment variables of the file when it is running. The above problem is that some environment variables of uboot are set in addition to the problem.

The modified method is as follows :

set bootcmd 'movi read kernel 30008000; bootm 30008000'

set bootargs console=ttySAC2,115200 root=/dev/mmcblk0p2 rw init=/linuxrc rootfstype=ext3

Finally don't forget to save: save.

At this point, go to shutdown and restart, and all problems are solved at this time.

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2018-4-15