BSP Developer's Guide

VxWorks 5.5
BSP Developer’s Guide
Handling a Polling Receive: endPollReceive( )
Your endPollReceive( ) is used by any task (such as the debug agent) that wants
to do a polling receive.
NOTE: When the system calls your endPollReceive( ), it is probably in a mode that
cannot service kernel calls. Thus, this entry point should not call any kernel
functions, such as taking a semaphore or allocating memory. Likewise, this entry
point should not block or busy wait because that would probably hang the entire
system.
Your endPollReceive( ) must take the following form:
int endPollReceive
(
void* pCookie, /* device structure */
M_BLK_ID pMblk /* place to return the data */
)
Your endPollReceive( ) should check that the device is set to polled mode (by a
previous endIoctl( ) call). Your endPollReceive( ) should then get a packet directly
from the network and copy it to the mBlk passed in by the pMblk parameter.
Your endPollReceive( ) entry point should return OK or an appropriate error
value. One likely error return value is EAGAIN. Your endPollReceive( ) should
return EAGAIN if the submitted mBlk was not big enough to contain the received
packet, or if no packet is available.
The parameters are:
pCookie
Passes a pointer to the END_OBJ structure returned by endLoad( ).
pMblk
Passes in a pointer to an mBlk structure. This parameter is an output
parameter. Your endPollReceive( ) must copy the data from the stack to the
mBlk structure referenced here.
Adding a Multicast Address: endMCastAddrAdd( )
Your endMCastAddAddr( ) entry point must add an address to the multicast table
that is maintained by the device. Your endMCastAddAddr( ) must take the
following form:
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