How can i use the same variables in different sub-project using S32DS?

[timwang]

I want to use core0 to receive some CAN data,and then transmit these data to the terminal by using core1.So i write some code in these two sub-project,how can i transmit  the data which i received in project Z4_1 in project Z4_2?

My development board is devkit-mpc5748g。

The following attachment is my project！

Regards

Original Attachment has been moved to: enet_rmii_udp.rar

[jiri_kral]

Hello, 

you can use shared memory. Here is example for multi-core shared memory usage: 
https://community.nxp.com/docs/DOC-335344 

Example is for S32R274, but you can use this technique for MPC5748G too. 

Jiri

[timwang]

Do i have to add the two files into all the sub-project?

In this example,only the z7_0 project contain the 'shared_mem' and the 'shared_func' file.

Regards

[jiri_kral]

Hi, 

you also need to modify linker files for all cores. Please check the linker files in the example and  your project (Your Project Name->Project_settings->Linker_files). You need to add path for shared objects (shared_mem.o and shared_func.o) into project settings (see screenshot bellow). Source codes - shared_mem.c and shared_func.c needs to be build by the firstly built core project (one of the cores is always build as the first and I can't find way how to change the build sequence - looks like that it is alphabetically sorted). 

The basic idea is

•  one memory space and starting address shared across cores (one instance for all cores) - technically linked shared_mem.o object on the very same address for each core
• usage semaphores for accessing shared memory  (one instance per core) - technically linked shared_func.o on unique address for each core. 

Here is linker file with added shared mem location: 

[timwang]

Hi Jiri,

Thank you very much !

It works for me!

But i still have this problem.As the picture showed below,In project Z4_1,i have change the value of the Tx_Message which is a shared variable，but in project Z4_2,the value of the Tx_Message is still previous value,Why?How can i solve this problem?

Thanks

Regards

[jiri_kral]

There may be couple reasons. Are you unlocking shmem access? Do you have only one source code for shmem/shfunc in the Z2_3 project and for other cores is linked object file from Z2_3 core? 

If you attach your update project - I'll look at it. 

Jiri 

[timwang]

I still have a question that when i import a project,in debug process,if i want to set a breakpoint in Z4_2 project,it always can not be effective,and the console window shows these messages：

And the breakpoint in Z4_1 project is effective.

Regards

[jiri_kral]

I have no issue about sources. Did you start debug session as a launch group? 

Your issue also may be caused by spaces in the path - like "S32 Design IDE". You can try to locate your workspace in the path without spaces. 

Jiri

[timwang]

Hi Jiri,

Actually,in core0 ,i keep receiving data from CAN_0,and store the data in Tx_Message.In core1,i read the data in Tx_Message and transimit them by ENET.

My problem is that in core1,only the first data in Tx_Message can be read normally.When the data that core0 received changed,Tx_Message should also change.But in Z4_2 project,the Tx_Message didn't change.

For example,the data that core0 recevied first are{253,53,86,102},then the data changed to {10,55,86,102},the Tx_Message shoule change to{10,55,86,102}.But on debugging,if i choose the Z4_1 debug,the Tx_Message are{10,55,86,102}, if i choose the Z4_2 debug,the Tx_Message are still{253,53,86,102}.

The pictures below show the state

I dont't know why it happend.Please help me.

Thank you!

[jiri_kral · Accepted solution]

Hi, 

this is really strange. But technically - there is only one Tx_Message instance on address 0x400B8090 - as you can see in your debug window. I can't reproduce it with test data. You have enabled I_CAHE and D_CACHE for Z4_2 core - try to remove these defines from your project settings for test:

I also can't see any difference on screenshots - may be I don't get the correct order. there are the very same data on picture #1 and #2 and different same data on #3 and #4.  

Jiri

[timwang]

Hi Jiri,

Thank you very much!

Disabling I_CAHE and D_CACHE for Z4_2 core works for me！

Regards

[timwang]

Hi Jiri,

I'm sure that i do all these configuration as you say.

Now,i attach my project below,if you have some free time,please look at my project.

Apologize for taking up your time.

Thank you very much!

[jiri_kral]

Hi, 

I tested your project - and for me it is working normally. But I used test data only (no real message from ethernet).It is good idea to add some flag in the shared memory - like NewDataReady - and Core 2 should process incoming  data only when new data is ready. 

In attachment is project with test values. 

[timwang]

Hello Jiri,

I have added these two files shared_mem and shared_func into my project.But i still have thses faults,do i have to make some other configuration?

Regards