New 8KB Bootloader: uf2-samd21

SAM-BAR (Smart Atmel Microcontroller Boot Assistant Reloaded) is a Combo USB CDC+MSD Bootloader for Atmel/Microchip SAM D21 devices (ARM Cortex-M0+). It is based on the following bootloaders:

• SAM-BA (AppNote AT07175) by Atmel/Microchip (www.atmel.com)
• Arduino Zero Bootloader by Arduino LLC (www.arduino.cc)
• SAMD-MSD-Bootloader by Justin Mattair (www.mattairtech.com)

• SAM-BA and Arduino Zero compatible Bootloader (USB CDC/VCP)
• Mass-Storage-Device Bootloader (USB MSD/MSC)
• Fits in 16KB (user program start at 0x4000)

• Bootloader Source Code
• Board Support Package for Arduino IDE