USBLib_CtrlMsg (SWI &56340) — Starts a transaction using a formatted control message.
| R0 | pipe |
| R1 | Data URB (0 if no data to be transfered) |
| R2 | Message URB |
| R3 | waiting template |
| R4 | bmRequestType (8bit) |
| R5 | bRequest (8bit) |
| R6 | wValue (16bit) |
| R7 | wIndex (16bit) |
| R0 | waiting |
| R1,R2,R3,R4,R5,R6,R7 | Preserved |
This call starts a USB control transaction by taking the supplied values and creating the properly formatted control message in the supplied URB (R2) then starting a transaction with the appropriate parameters.