Overview

This file contains a design example for using the Mailbox hardware and driver XMbox.

This example attempts to send a known message through the mailbox from the processor identified as 0 (XPAR_CPU_ID=0) to the other processor. The message is received by the receiver and the test passes. Since the application is running on two seperate processors, the initiator declares success when the message is sent and the receiver declares success when the message is received. There is no feedback to the initiator so a terminal is required for each processor to verify that the test passed for both sides.

The example assumes there are two processors availabile in the system that are expected to inter-communicate.

This example has been tested on ML505 Hardware Evaluation board.

Note

These code fragments will illustrate how the XMbox component can be used to:

Initialize the Mailbox core.
pass data between two processors.

  MODIFICATION HISTORY:

  Ver   Who  Date        Changes



  2.00a hm              Example that sends and receives and uses interrupts
  3.01a sdm  05/06/10   Cleanup for coding guidelines, removed printfs from all
                        the functions except the main function
  4.1   ms   01/23/17 Modified xil_printf statement in main function to
                      ensure that "Successfully ran" and "Failed" strings
                      are available in all examples. This is a fix for
                      CR-965028.
        ms   04/05/17 Added tabspace for return statements in functions for
                      proper documentation while generating doxygen and
                      modified filename tag to include the file in doxygen
                      examples.
  4.6   ht   07/07/23 Added support for system device-tree flow.
*

Functions
int	MailboxExample (XIntc *IntcInstancePtr, u16 MboxDeviceId, u16 MboxIntrId)
	This function sends a message to and receives a message from the other processor. More...

int	MailboxExample_Send (XMbox *MboxInstancePtr, int CPU_Id, int Blocking)
	This function sends the hello message to the other processor. More...

int	MailboxExample_Receive (XMbox *MboxInstancePtr, int CPU_Id, int Blocking)
	This function receives a message from the other processor verifies it's the expected message. More...

int	MailboxExample_Wait (volatile int Count, char Name, int Threshold)
	This function waits for a particular variable to exceed the threshold value. More...

int	main (void)
	This function is the main function for the mailbox interrupt example. More...

Function Documentation

int MailboxExample	(	XIntc *	IntcInstancePtr,
		u16	MboxDeviceId,
		u16	MboxIntrId
	)

This function sends a message to and receives a message from the other processor.

It also uses the interrupt to check whether the other processor has started to send or receive.

Parameters

IntcInstancePtr	is the device instance of the interrupt controller that is being worked on.
MboxDeviceId	is the Mailbox device ID.
MboxIntrId	is the Mailbox interrupt ID.

Returns

XST_SUCCESS if the test passes
XST_FAILURE if the test fails

Note: None

References XMbox_Config::BaseAddress, XMbox::Config, MailboxExample_Receive(), MailboxExample_Send(), MailboxExample_Wait(), XMbox_Config::UseFSL, and XMbox_CfgInitialize().

Referenced by main().

int MailboxExample_Receive	(	XMbox *	MboxInstancePtr,
		int	CPU_Id,
		int	Blocking
	)

This function receives a message from the other processor verifies it's the expected message.

Parameters

MboxInstancePtr	is the instance pointer for the XMbox.
CPU_Id	is the CPU ID for the program that is running on.

Returns

XST_SUCCESS if the receive succeeds
XST_FAILURE if the receive fails

Note: None

References XMbox_Read(), and XMbox_ReadBlocking().

Referenced by MailboxExample().

int MailboxExample_Send	(	XMbox *	MboxInstancePtr,
		int	CPU_Id,
		int	Blocking
	)

This function sends the hello message to the other processor.

Parameters

MboxInstancePtr	is the instance pointer for the XMbox.
CPU_Id	is the CPU ID for the program that is running on.
Blocking	is set to 1 for the send to block till the data is sent.

Returns