This allows to bringup the USB PHY and the HPM for the
payload without having to initialize the CDC ACM driver
at the same time.
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Next stage boots now exit back to main() after replying to the proxy
command, allowing shutdown functions to be called. Introduces a new
P_VECTOR proxy op, distinct from P_CALL. The Python side is reworked
to remain compatible with older versions that do not support this.
Signed-off-by: Hector Martin <marcan@marcan.st>
