README

Test for USB Mass Storage Gadget by Mike Messinides

This test program allows to access the SD card from a connected USB host. It
works on the Raspberry Pi (3)A(+), Zero (2) (W) and 4B in USB gadget mode. These
models allow to connect the on-board DW USB controller directly to an USB host
for USB gadget (aka device) operation. The Raspberry Pi 4B uses the USB-C power
connector for that purpose. You need a suitable USB cable. The Raspberry Pi is
normally bus-powered via the USB host in any case for this test. A separate
power supply need not be connected.

If you want to self-power your Raspberry Pi, you have to ensure that the supply
voltages at the USB connector and the power connector are exactly the same.
Otherwise there is a risk of damage. Be careful!

A configuration is required for this test. You have to define the macro
USB_GADGET_VENDOR_ID with your USB Vendor ID to be used for the USB device. See
the file include/circle/sysconfig.h for details!
