How to use the Cortex A5 linux port, we have downloaded the Cortex A5 designstart to the Mps3 development board.

Do you mean how to install the Linux image to the board?

You should download and build the example as described here:

https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms.git/about/docs/user-guide.rst

Then copy the binary files to the board as described here (section 6):

https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms.git/about/docs/ca5ds/user-guide.rst

Regards

Ronan

sir , I have followed the example above and run the iota-tiny linux system on the MPS3 board. Now I can sign in the system using terminal .however I can't make a file transfer between host machine and the board.because this minimal system don not have the module required. So I just go to the yocto official website and want to learn how to build the software(like openssh) into the image. However ,I've tried some times,and I can not succeed on Arm platform like the website example showed. I want to know is there any tutorial I can successfully build some file transfer sofeware into the image for arm A5 platform，so i can run a helloworld on the MPS3 board or send some files from host machine to the board.
Thanks ！！！
the yocto website I followed are:
1.wiki.yoctoproject.org/.../Cookbook:Example:Adding_packages_to_your_OS_image
2.docs.yoctoproject.org/.../index.html