| driver number |
|---|
1 |
The console driver allows the process to write buffers to serial device. To
write a buffer, a process must share the buffer using allow then initiate the
write using a command call. It may also using subscribe to receive a
callback when the write has completed.
-
Description: Does the driver exist?
Argument 1: unused
Argument 2: unused
Returns: Ok(()) if it exists, otherwise NODEVICE
-
Description: Initiate a write transaction of a buffer shared using
allow. At the end of the transaction, a callback will be delivered if the process hassubscribed.Argument 1: The maximum number of bytes to write. If this argument is greater than or equal to the buffer's size, the entire buffer will be written. Otherwise, the first N bytes of the buffer will be written, where N is the value of this argument.
Argument 2: unused
Returns: Ok(()) if the command was successful, BUSY if no buffer was shared, or NOMEM if the driver failed to allocate memory for the transaction.
Additional notes: A process may call this command with a write size of
0to cancel a write transaction, if one is ongoing. Unless an error occurs, this will generate a write transaction completed event, regardless of whether or not a write transaction was already in progress. -
Description: Initiate a read transaction into a buffer shared using
allow. At the end of the transaction, a callback will be delivered if the process hassubscribedto read events usingsubscribe number2.Argument 1: The maximum number of bytes to read.
Argument 2: unused
Returns: Ok(()) if the command was successful, BUSY if no buffer was shared, or NOMEM if the driver failed to allocate memory for the transaction.
-
Description: Abort any ongoing read transactions. Any received bytes will be delivered via callback if the process has
subscribedto read events usingsubscribe number2.Argument 1: unused
Argument 2: unused
Returns: Ok(()) if the command was successful, BUSY if no buffer was shared, or NOMEM if the driver failed to allocate memory for the transaction.
-
Description: Subscribe to write transaction completion event. The callback will be called whenever a write transaction completes.
Callback signature: The callback receives a single argument, the number of bytes written in the transaction. The value of the remaining arguments is undefined.
Returns: Ok(()) if the subscribe was successful or NOMEM if the driver failed to allocate memory for the transaction.
-
Description: Subscribe to read transaction completion event. The callback will be called whenever a read transaction completes.
Callback signature: The callback receives two arguments. The first is a statuscode, containing any error if one occurred. The second is the number of bytes read in the transaction. The value of the remaining arguments is undefined.
Returns: Ok(()) if the subscribe was successful or NOMEM if the driver failed to allocate memory for the transaction.
-
Description: Sets a shared buffer to be used as a source of data for the next write transaction. A shared buffer is released if it is replaced by a subsequent call and after a write transaction is completed. Replacing the buffer after beginning a write transaction but before receiving a completion callback is undefined.
Returns: Ok(()) if the subscribe was successful or NOMEM if the driver failed to allocate memory for the transaction.
-
Description: Sets a shared buffer to be read into by the next read transaction. A shared buffer is released in two cases: if it is replaced by a subsequent call or after a read transaction is completed. Replacing the buffer after beginning a read transaction but before receiving a completion callback is undefined.
Returns: Ok(()) if the subscribe was successful or NOMEM if the driver failed to allocate memory for the transaction.