As 2017 New Year Resolution, I set out to make a Single Board Computer(SBC) from scratch and then write an OS for it. The SBC is ARM based and the design files can be found here. Though my initial plan was to write an OS for the board(i.e. ARM based), I decided to write an x86 based OS first because of abundantly available resources and then use what I've learnt to build a smaller ARM based OS.
To compile the code, you need a cross compiler which can be built by following the instructions given here. Make sure that you've built the compiler in the same directory as the OS's source code.
After the build is over, simply run make to compile and use a virtual machine to run
the generated .bin file. For qemu, this is the commad qemu-system-i386 -kernel myos.bin