Methods and Tools for Mapping Process Networks onto Multi-Processor Systems-On-Chip - Signal Processing Systems - page 869

ARM tile 1 ARM tile N

instruction
and data
memory

instruction
and data
memory

ARM
core

ARM
core

scratchpad
memory

DMA
controller

scratchpad
memory

DMA
controller

S M M S M M

bus

Fig. 8 Block diagram of the MPARM architecture

synthesis for the Cell Broadband Engine is described in [ 24 ] in the context of the
DOL design flow, and in [ 66 ] in the context of the SHIM design flow, for instance.
Listing 1 shows parts of a main file for a producer-consumer type application
running on MPARM. In lines 2 - 3 , memory is allocated for the local data of the
producer and consumer processes. In lines 6 - 9 , two tasks are created for the
processes by allocating a task control block, by assigning a task name and a task
ID, by allocating a stack, and by setting initial attributes like the task priority and
the task mode. Lines 11 - 12 show the creation of a message queue. In lines 14 - 18 ,
the rtems task start directive puts the tasks into the ready state, enabling the
scheduler to execute them. Finally, the initialization tasks deletes itself (line 20 ) .
Listing 1 RTEMS initialization task in which two tasks are bootstrapped to run a producer and
consumer process of a process network

rtems task Init ( rtems task argument arg ) {

1

producer wrapper ← malloc ( sizeof ( RtemsProcessWrapper ) ) ;

2

consumer wrapper ← malloc ( sizeof ( RtemsProcessWrapper ) ) ;

3

4
5

for (j ← 0; j < 2; j ++) {

status ← rtems task create ( j + 1, 128,

6

RTEMS MINIMUM STACK SIZE , RTEMS DEFAULT MODES ,

7

RTEMS DEFAULT ATTRIBUTES , &( t a s k id [j ]));

8

} 9

10
11 status ← rtems message queue create (1 , 10, 1,

RTEMS DEFAULT ATTRIBUTES , &q u e u e id [0]); 12

13
14

status ← rtems task start ( task id [1] , producer task ,

(rtems task argument ) producer wrapper );

15

16
17

status ← rtems task start ( task id [2] , consumer task ,

(rtems task argument ) consumer wrapper );

18

19
20

rtems task d e l e t e ( RTEMS SELF ) ;

}

21