Is the DTR signal connected (via a 100nF) to reset ?
Which bootloader did you use?
Burning the bootloader is not enough, did you set the fuses according to the Arduino fuse settings?
To add a new board to boards.txt is very well possible. Perhaps you made an error. Why is that not compiling?
So you see, there are many problems with this.
EDIT: I removed some lines that were wrong.