Exynos4412 bare metal program: DDR working principle and timing (Part 2)

How to transfer files between Tiny4412 and PC:

There are currently four main ways to download the compiled executable file to the target board:

The first method: transfer files to the development board via FTP (recommended)

The second method: copy to a medium (such as a USB drive)

The third method: transfer files to the development board through the serial port

Fourth: Start with nfs file system as the root file system

The following are introduced separately:

1. Use ftp to transfer files (recommended):

Note: Use FTP to log in to the target board and upload the compiled program; then modify the executable properties of the program on the target board after uploading and execute it.

First, execute on the PC as follows:

ftp 192.168.48.151

Username: plg

Password: plg

Set the file transfer format: bin

Send hello file: put hello

Log out: by

Then, execute on the target board side as follows:

Go to the receiving directory: cd /home/plg/

ls

Add executable permissions: chmod +x hello

Run the test: ./hello

2. First copy the compiled executable program to the USB drive, then insert the USB drive into the target board and mount it, and then copy the program to the executable directory/bin of the target board:

①. Copy the program to the USB drive

Insert the USB drive into the USB port of the PC and execute the following command to copy the program to the USB drive:

#mount /dev/sda1 /mnt ; mount the USB drive

#cp hello /mnt ; copy the compiled program to the USB drive

#umount /mnt ; Unmount the USB drive

②. Copy the program from the USB drive to the target board and execute it

Insert the USB drive into the USB Host interface of the development board. The USB drive will be automatically mounted to the /udisk directory. Execute the following command to run the hello program.

#cd /udisk

#./hello; execute the hello program

Note: If you forcibly unplug the USB drive at this time, you need to return to the root directory and execute umount /udisk to prepare for automatic mounting next time.

3. Transfer files to the development board via the serial port:

In Chapter 5.3.5, we learned how to transfer files to the development board through the serial port. You can also use the same method to transfer the hello executable program. The specific steps will not be described in detail here. Remember to change the file attributes to executable after the transfer is completed so that it can run normally.

#chmod +x hello

Note: Some users use USB to serial port cables. Because the performance of some adapters is not very good, sometimes "transmission timeout" or failure to transmit to the development board may occur. Therefore, we recommend using FTP to transmit to the development board.

4. Start with nfs file system as the root file system:

①. Refer to the blog post " Tiny4412 Friendly Arm ARM Development Board Static IP Settings (Restart Valid) " to set the IP of the development board to static;

  Refer to the blog post " How to install NFS service and its configuration in Ubuntu " to start Ubuntu's nfs service

②.Ubuntu installs nfs service:

      sudo apt-get install nfs-kernel-server

  Ubuntu nfs restart service

      sudo /etc/init.d/portmap restart

      sudo /etc/init.d/nfs-kernel-server restart

  View nfs server on Ubuntu:  

      sudo /etc/init.d/nfs-kernel-server start //Check whether nfs is started

③.Add permissions:

sudo vi /etc/exports

Add to:

/home/book/workspace/tiny4412_project/rootfs_qtopia_qt4 *(insecure,rw,async,no_root_squash)

/home/book/workspace/tiny4412_project/new_fs_tiny4412 *(insecure,rw,sync,no_subtree_check,no_root_squash)

sudo chown book:book /home/book/workspace/tiny4412_project/rootfs_qtopia_qt4/ -R

sudo chown book:book /home/book/workspace/tiny4412_project/new_fs_tiny4412/ -R

chmod 777 /home/book/workspace/tiny4412_project/rootfs_qtopia_qt4

chmod 777 /home/book/workspace/tiny4412_project/new_fs_tiny4412

④.Try to hang it on yourself on Ubuntu:

  //Mount the file system provided by the manufacturer

  sudo mount -t nfs -o nolock,vers=2 192.168.48.104:/home/book/workspace/tiny4412_project/rootfs_qtopia_qt4 /mnt 

  //Mount your own file system

  sudo mount -t nfs -o nolock,vers=2 192.168.48.104:/home/book/workspace/tiny4412_project/new_fs_tiny4412 /mnt   

  sudo umount /mnt

⑤. Manually mount nfs on the tiny4412 development board:

  //Mount the file system provided by the manufacturer

  mount -t nfs -o nolock,vers=2 192.168.48.104:/home/book/workspace/tiny4412_project/rootfs_qtopia_qt4 /mnt   

  //Mount your own file system

  mount -t nfs -o nolock,vers=2 192.168.48.104:/home/book/workspace/tiny4412_project/new_fs_tiny4412 /mnt     

⑥. The tiny4412 development board nfs is started as the root file system (self-made file system):

Reference: " Start u-boot from SD card and burn bare board and system " and " Use fastboot tool to download uboot, linux and file system of tiny4412 ". After compiling and burning uboot, linux and filesystem, use eMMC to start the development board and set the ip address of the development board when linux starts. Then set the uboot parameter bootargs and use nfs to start the root file system:

Modify the command line:

default:

set bootargs root=/dev/mmcblk0p2 init=/linuxrc console=ttySAC0,115200 lcd=S70 ctp=2

to:

seten bootargs noinitrd root=/dev/nfs nfsroot=192.168.48.104:/home/book/workspace/tiny4412_project/new_fs_tiny4412 ip=192.168.48.100:192.168.48.104:192.168.48.255:255.255.25 5.0::eth0:off init=/ linuxrc console=ttySAC0,115200 lcd=S70 ctp=2

Note: Tiny4412 uses a USB network card, which is not supported by the current uboot. Therefore, it is not possible to start uboot with nfs as the root file system. You can refer to the following "Driver Test and Development Environment" to set up automatic mounting of the nfs file system after Linux starts.

DTB Device Tree video tutorial: Taking Renesas Cortex-A15 as an example:

http://www.hexiongjun.com/?s=Device+Tree

Tiny4412 bare metal program summary address:

http://www.100ask.org/bbs/forum.php?mod=viewthread&tid=11778&highlight=tiny4412

iTOP-4412 implements NFS network file system startup (including installing Ubuntu NFS service, compiling and configuring the kernel)

http://www.oschina.net/question/2371345_2158782

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Drive test to build development environment:

Since the startup failed when using nfs as the file system, mount the server's /home/book/workspace/tiny4412_project/driver/mountfile directory to the development board's mnt directory after the kernel starts:

Modify the file on the development board: vi /etc/init.d/rcS

Add below the modification of the development board startup IP address:

mount -t nfs -o nolock,vers=2 192.168.48.104:/home/book/workspace/tiny4412_project/driver/mountfile /mnt

Note: After adding permissions to the mountfile directory in Ubuntu, you need to restart the virtual machine. Restarting the development board will automatically mount the Ubuntu mountfile directory in the development board/mnt directory.