Renesas RCAR M3N - USB Download mode

Deepak R · Post by **Deepak R** » 6. Feb 2024, 17:25

I am using Renesas RCAR M3N Salvator evaluation board. The RCAR SOC has an inbuilt recovery mode called "USB Download mode".
With this mode the USB is enumerated as an ACM device, and I can flash the required binaries to hyperflash. I noted a peculiar behaviour in Windows Host machine running a Linux VM Ubuntu 20.04

Working case:
In Linux native/Windows native machine,

Open minicom/TeraTerm to USB and the SCIF ports
Upload the Flash writer monitor file in ascii mode via USB
Prints from monitor file appearing in both the USB device and SCIF (Serial) port
After entering text into USB device, further prints are coming only from USB device.
Likewise if a text is entered into SCIF port, further prints are coming only from the SCIF port

Issue case:
Windows: 10
Virtual box Version: 7.0.12 r159484 (Qt5.15.2)
VirtualBox 7.0.12 Guest Additions for Linux
Ubuntu 20.04
Above described steps are followed, but its observed that

Entering text into USB device is unresponsive
The prints are appearing only in SCIF port
After entering text into SCIF port, further prints are coming only from the SCIF port

When searching in the Renesas community forum, I am unable to find any post related to RCAR SoC.
Has someone faced/solved this issue? It would be great for suggestions on how to solve this in VM machine.

Thank you!