Dear Epic Team,
I cannot find any specs about platform requirements to build apps on Linux.
Is it possible build on Linux ARM platform?
Thanks
P.S: I open also this thread on forum https://forums.unrealengine.com/showthread.php?6243-Deploy-on-ARM-Linux-board
I replied on the forum as well 
(https://forums.unrealengine.com/showthread.php?6243-Deploy-on-ARM-Linux-board&p=48755&viewfull=1#post48755), but copying/pasting the reply here for completeness:
Right now we only support x86-64, although in the past I got dedicated server running on Raspberry Pi and can help you with this. This does not work out of the box, some code changes will be needed. You will also need our help getting certain third-party libs compiled for your target.
We also don’t supply a prebuilt ARM cross-toolchain. You can build one by modifying our ct-ng configs that we ship with x86-64 cross-toolchain though.
I recently got cross compiling working with the following configuration:
build machine is Linux_x64 target is Linux_ARMv7_hardfp
Currently able to run the SunTemple demo on Jetson Tk1 platform.
The toolchain used is the arm-linux-gnueabihf linaro cross toolchain that can be downloaded.
Is there any interest/objection to attempt integration of this cross compile ability to the main tree ?
I want to take a look, but I am curious what (and why) you had to change. Normally you don’t need to change anything except the default architecture in UEBuildLinux.cs
The current method for cross compiling seems to be supported only with Win_x86 as the build system. Whether or not cross compiling is being done or not is detected by checking “if Current.Platform != Linux” in LinuxToolChain.cs. Please correct me if I’m wrong.
While this works fine for windows machine as far as I know this does not work when cross compiling from Linux_x86 to Linux_ARM because both platforms are considered Linux.
I find it a lot more convenient, just personally, to work from a linux build host. My changes above is to enable this Linux_x86 → Linux_ARM cross compile.
Is there any plan to support this method of cross compile in the future ?
Yes, we want to support cross-compilation on Linux too (both x86 to ARM and even between different x86 sysroots to e.g. target an older system like CentOS 6.x). If you feel that your changes are sound and ready to be incorporated into UBT, feel free to submit a PR! Thanks in advance.
Now we supply the ARM cross-toolchain: https://s3.amazonaws.com/unrealengine/qfe/arm-unknown-linux-gnueabihf_v5_clang-3.5.0-ld-2.23.1-glibc-2.13.zip
Thanks. I will submit a pull request for Linux_x86 to Linux_ARM cross compile after cleaning up, which might take a bit of time. In the meantime cross compile from Windows to Linux-ARM seems to be working after the release of the appropriate cross compile toolchain (thanks !!!). I have modified A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums to reflect the steps that I found worked for me to get SunTemple to run on Jetson TK1. Please correct any mistakes or let me know and I will do so.
Was the pi running raspi os or what distro did you use?