Firmware Compiling Help - What is the exact process?  

Firmware Compiling Help - What is the exact process?

Hello,

I have downloaded Arduino, removed the Liquid Crystal library from it, I have also installed the Arduino Addons from the Repo as specified.

I have never used used Arduino before so I need to know the following:

• What are the libraries that need to be visible?
• What settings and options need to be selected and set before compiling?
• Please tell me everything that needs to be in place to successfully build and compile firmware for my Original Prusa I3.

I don't want to get this wrong.

When I ran compile I got the following message, can you tell me what is wrong, what am I missing?

WARNING: Category '' in library Wire is not valid. Setting to 'Uncategorized'
Build options changed, rebuilding all
Warning: platform.txt from core 'Marlin AVR Boards' contains deprecated recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/{archive_file}" "{object_file}", automatically converted to recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{archive_file_path}" "{object_file}". Consider upgrading this core.
Bootloader file specified but missing: C:\Program Files (x86)\Arduino\hardware\marlin\avr\bootloaders\stk500boot_v2_mega2560.hex

Sketch uses 120,468 bytes (46%) of program storage space. Maximum is 258,048 bytes.
Global variables use 6,526 bytes of dynamic memory.