Programming basic environment variable setting of in-house SOC

This article is actually from 2019 Started writing in , Due to the principle of work demand , Always put it , Now pick up linux, Start with your own development board .

Based on the arm of kindness smart210 Start linux

The development board is 2013 Bought in , Until now , stay 2019 I once played for a period of time , But the project can't be used, so it's now , Later linux It will be my own direction , So take it out and study it carefully . First, get familiar with the basic operation .

Use SD Kalai starts the development board

To achieve this step , First use SD-Flasher hold superboot-210 write in SD card .

The first SD Card in computer , Open... With administrator privileges SD-Flasher

Pay attention here , If you don't use the one that comes with your computer SD cassette , Be sure to pull it out , Here is a piece SD The data disk is formatted , Caused certain repeated operations , At the same time, I lost the information of Quanzhi before . The rest goes without saying , This tool is formatted 130M Left and right space to guide , Equivalent to the startup disk when installing the computer .

To burn different systems, edit the burning configuration file ,FriendlyARM.ini This file

In this document Action Item is the main setting item .
Set the action to be performed , It can be for Install/Run/Null, Represent the ：
Install - The installation to Nand Flash;
Run – Directly from SD The card runs
Null - No action ; Set to null time , Also said NULL
The default is “Install”

Copy the second CD images Folder to SD Cary

There is already linux image ,andriod image , Just edit the burning configuration file , Get it on the development board and set it to SD Just start the card , Finish from SD Card activation , Or burn to NandFlash.

Use MiniTools Brush system

Install this tool , Don't say , stay win It's going well .
This tool , Also needed SD card , however ,sd Cary can use no image file , Just the configuration file FriendlyARM.ini, increase USB-Mode=yes.
then ,s2 Switch to sd Card or USB Boot mode -> Power on again , The development board will stop at USB mode waitting state .

Measured installation mini tools Manual installation will appear fastboot drive ？ Then it will appear “ Hash value of file Error not in the specified directory ”

Or disable digital signatures , Please refer to win Embedded environment construction and frp Intranet through

win10 The next big probability will appear mini tools Unable to identify the problem of the device , Or the drive always has a cross

These are all problems caused by digital signatures , Generally, you need to restart , Disable digital signatures , You can use it once .

arm System preparation

Brush several systems back and forth , ok , Enter the real embedded stage .

linux Three pieces

bootload: System boot ;kernel： kernel ;RootFS(AP): The root file system

Build cross compiling environment

Put the first CD directly ->linux->arm-linux-gcc-4.5.1-v6-vfp-20120301.tgz copy to ubuntu Next , Unzip to /opt/FriendlyARM/toolschain/4.5.1/bin
The command executed is ：tar -zxvf arm-linux-gcc-4.5.1-v6-vfp-20120301.tgz /opt
The last step , It is also added to the environment variable , It's just added to /etc/environment, Do this by adding , There are some problems , If there are two cross environments , There's a problem , So it's best to put ~/.bashrc in .

/etc/environment And ~/.bashrc What is the difference between the added environment variables ？

It's really not just these two , also etc/profile、/etc/bashrc

Set global environment variables

etc/profile: This file sets the environment information for each user of the system . When the user logs in , The file is executed once , And from /etc/profile.d Directory of configuration files shell Set up . Generally used to set global variables used by all users .

#  If /etc/profile The file is not editable , Need to change to editable 
chmod -v u+w /etc/profile

vim /etc/profile

#  Add in the last line 
export PATH=$PATH:/home/uusama/mysql/bin

/etc/bashrc: When bash shell When opened , The file is read . in other words , Open a new terminal every time shell, The file will be read .

#  If /etc/bashrc The file is not editable , Need to change to editable 
chmod -v u+w /etc/bashrc

vim /etc/bashrc

#  Add in the last line 
export PATH=$PATH:/home/uusama/mysql/bin

/etc/environment It is also a global variable , In terms of the function of the document itself , /etc/environment Set the environment of the whole system , and /etc/profile It's setting up the environment for all users ./etc/environment Cannot contain command , Directly through VAR=“…” How to set , Don't use export .

#  If /etc/bashrc The file is not editable , Need to change to editable 
chmod -v u+w /etc/environment

vim /etc/environment

#  Add in the last line 
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"

Only for single user environment variables

~/.bashrc: Works only for a single user , When logging in and opening new shell when , The file is read .
export The mode is only applicable to the current terminal Shell It works .

vim ~/.bashrc// In addition to the current user , There's another. /root/.bashrc file ,root User 
#  Add in the last line 
export PATH=$PATH:/home/uusama/mysql/bin
# When it's done ,source Make settings take effect immediately 
source ~/.bash_profile take effect 

problem

Compile the simplest program , newspaper error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory error

Missing Library , perform sudo apt-get install lib32z1, that will do