$ sam-ba -h
$ dfu-util -D SendcommLWOTAA-rel.bin

# USB host is unable to program flash ## Problem environment Using a custom bootloader, MCU flash storage can be programmed over the USB. This feature could allow a connected host (USB DFU like on Arduino) to reprogram the sendcomm transceiver. ## Expected result The *dfu-util(1)* or *sam-ba(1)* applications can be used to load and program a SAMR34 (Cortex-M0+) firmware to the chip's flash storage. ``` $ sam-ba -h $ dfu-util -D SendcommLWOTAA-rel.bin ``` ## Actual result There is no possibility of programming the chip's flash storage conveniently using *dfu-util(1)*. ## Notice In the document SAM R34 MLS Getting Started Guide, the section 5.5 Bootloader contains the information Figure 5-8. Bootloader Organization in SAM R34 providing clues how to implement this feature. ## Resources https://www.github.com/atmelcorp/sam-ba/ ## Workaround Use a serial debugger (JTAG/SWD) in the usual manner. ## Severity level This is **low priority** because no requirements specify the feature.