RTOS/TDA2PXEVM: Global variables not initialized in IPU ( M4 )

Hi Shiju,

I made --zero_init=on for LNKFLAGS_GLOBAL_ipu1_0 and LNKFLAGS_GLOBAL_ipu1_1 in source\vision\platform\ti\tda2\build\rtos\makerules\build_config.mk. file.

After this change I checked the global variable values again but they weren't still initialized. Could you please mention the location where the change needs to happen?

Also, in the same file for LNKFLAGS_GLOBAL_a15_0, no value for zero_init was set. Is that correct?

I searched all the places where zero_init is off for IPU1_0 in the vision_sdk/build folder, but there is no override. Any other possibility do you suspect for it to be not working?

Does zero_init has to be set with any other combination of compiler/linker options? I had explored cinit_compression option but there is no effect with it's value also.

Poorva

We have used this in C66x & M4 CPUs, with TI compilers.

BTW, are you trying on A15 with GCC compiler?

If yes, this combination is not checked!

regards, Shiju

Hi Shiju,

We are also using M4 CPU with TI compiler (i.e. cg_tools), but it doesn't work for us.

Regards,
Poorva

Poorva

This needs to be checked again.

Meantime can you check the first option described in the beginning of the post?

regards, Shiju

Hi Anuj,

I tried the solution you had mentioned, but is there any other solution that zero initializes all the global variables automatically as it is not feasible for me to initialize each one of them individually.

I also tried the Shiju's solution but it does not seem to be working for us.

Regards,

Poorva

Hi,

I hope you are doing this for a specific section only.
You can keep some value in any variable which is in that section and after boot just check that 1 variable and if that has a value of 0 then it will work for the entire session.

Regards,
Anuj

Hi,

zero_init flag works on DSP but not on IPU core so using that you will not be initialize variables to 0.
You can try out the experiment which has been suggested earlier.

You can map all your wanted variables to a section like below assuming section name is "temp" and variable name "gVar"
#pragma DATA_SECTION(gVar, ".bss:temp")

Then open below file
links_fw/src/rtos/bios_app_common/${platform}/${core}/${core}.cfg
and map your temp section to data_memory section of that core like below assuming you are doing it for IPU1_0
Program.sectMap[".bss:temp"] = "IPU1_0_DATA_MEM";
Program.sectMap[".bss:temp"].type = "INIT";

Regards,
Anuj

Hi Anuj,

Thanks for the response. This resolves our query. But we want to understand the reason of this restriction for IPU.

Could you please help us understand that?

Regards,

Poorva

Hi Poorva,

Are you asking for IPU or MPU.

As the above example should work for IPU1_0 core.

Regards,

Anuj