3rd party HW boards: How to create a new manufacturer/board?

I have designed a Board with specfici sensors in the PCB based on the Arduino Zero design.

Because of my HW changes, I need to personalize some of the Arduino core files: 1. startup.c -> Clock configuration 2. wiring.c -> ADC Speed 3. I am also using my board without bootloader, so I have to change the boad.txt and change the line: arduino_zero_native.build.ldscript=linker_scripts/gcc/flash_without_bootloader.ld

I am using the standard arduino folder, therefore each update of the samd architecture forces me to manually change the above files again and again.

After IDE 1.5 is possible to define new manufacturers/boards according the 3rd party Hardware especification: https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5---3rd-party-Hardware-specification

I decided it was time to create my own board configuration (manufacturer/board). I have read it, and I have installed the Adafruit samd architecture to see how it works, I have copied all the adafruit files, and added them as a new manufacturer. I have also changed the names in the board.txt and platform.txt accordingly.

However there is no way that I can see my new board in the Arduino IDE menu, something is wrong with my directory/files, and are not accepted by the IDE.

To reproduce this problem, you only need to install Adafruit Feather SAMD directory structure (/home/user/.arduino15/packages/adafruit/hardware/samd/1.0.13/etc), copying the whole "adafruit" folder with a new name, and changing the board.txt (only manufacturer) and platform.txt, with the new manufacturer name.

What else do I need to change something else?

Thanks in advanced for you help. ,

The boards at /home/user/.arduino15 only show up if there is a matching entry in one of the JSON files in that folder(downloaded by Boards Manager according to File > Preferences > Additional Boards Manager URLs). So you will either need to install the package manually to the {sketchbook folder}/hardware folder or create a JSON file according to: https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.6.x-package_index.json-format-specification