After compiling a lot time the avr toolchain by myself, I found an easier solution.

I tried the gcc version 6.0.0, 4.8.9 and 4.9.2. There is are some problems with the gcc. every time i patched the new device, the gcc doesn't know about the Atmega328pb. It means, the device is never shown in the call:

$ avr-gcc --target-help

but I always could compile the for this device, so the gcc itself knew about. I used the information from the Patch, which someone from Atmel send to the gcc-developer. As someone want to know about all the patches, I did, I wrote all down. But just now, I want to describe the easy way.

Thanks to Atmel, they provide a toolchain for Windows and Linux. Because I am working with Linux, I downloaded the toolchain there:

http://www.atmel.com/tools/atmelavrtoolchainforlinux.aspx

This toolchain contains the gcc 4.9.2 with a few patches from the 6.0.0 version. I don't know exactly, which patches, but I analysed their compiling script (http://distribute.atmel.no/tools/opensource/Atmel-AVR-GNU-Toolchain/3.5.0/build-avr8-gnu-toolchain-git.sh).

But luckily, they have a finished toolchain. But now we need to add the device. These informations are int the AVR device pack: http://www.atmel.com/images/partpack_ATmega328PB-trunk-6.2.9.zip

But aware, these files are outdated already, there Atmel Studio has newer one.

In the end, I found 3 different header files. In one file, there were some Register missing.

Here is the another Pack Link, which is newer:

http://packs.download.atmel.com/ - Atmel ATmega Series Device Support (1.0.91)

We need the following files:

1. libatmega328pb.a
2. iom328pb.h
3. crtatmega328pb.o

Put the lib and the crtatmega328pb.o into "/avr/lib".
Put the io*.h into "avr/include/avr"

Done !

I also patched the "io.h", but this seems not necessary since the header file can build the filename by itself, when it is not found.

I put everything into Arduino, so I could easy see, if it's working. Because i made my own PCB, I made my own board.txt.

super.name=Super Mini

super.upload.tool=avrdude
super.upload.protocol=arduino

super.bootloader.tool=avrdude
super.bootloader.low_fuses=0xff
super.bootloader.unlock_bits=0x3F
super.bootloader.lock_bits=0x0F

super.build.f_cpu=20000000L
super.build.board=AVR_MINI
super.build.core=arduino:arduino
super.build.variant=super

## Super Mini w/ ATmega328PB
## -------------------------
super.menu.cpu.atmega328=ATmega328pb

super.menu.cpu.atmega328.upload.maximum_size=28672
super.menu.cpu.atmega328.upload.maximum_data_size=2048
super.menu.cpu.atmega328.upload.speed=115200

super.menu.cpu.atmega328.bootloader.high_fuses=0xd8
super.menu.cpu.atmega328.bootloader.extended_fuses=0x05
super.menu.cpu.atmega328.bootloader.file=optiboot/optiboot_atmega328pb.hex

super.menu.cpu.atmega328.build.mcu=atmega328pb 
super.build.extra_flags=

Finally I need to patch the avrdude.conf:

Simply add below the Atmega328 Part:

part parent "m328"
    id			= "m328pb";
    desc		= "ATmega328PB";
    signature		= 0x1e 0x95 0x16;

    ocdrev              = 1;
;

Later I explain about the bootloader...