The size argument specifies how many bytes should be read. It defaults to 4, but can be set to any positive value.
Providing initiator is rarely needed, but some devices may only accept accesses from certain initiating objects. If provided, initiator is the object that will be used as the source of the access.
The -l and -b flags are used to select little-endian or big-endian byte order, respectively. They determine how the bytes in memory should be interpreted as a value. If neither is given, the byte order of the initiator is used if specified and a processor, or else the order of the current frontend processor.
When used in an expression the command returns the value read.
If a request fails an error is reported.