OMAP-L138: switching ARM to the privileged mode leads to falling into an exception handler

Ok. I found out some information. My ARM core is running on SYSTEM mode. I can access to some registers through memory, but can't to another ones. I still can see them and can change their value in a 'Registers' view of CCS. When I try to watch them in a 'Memory Browser' view of CCS I've got an array of '?'.

There are some screenshots:

1) ARM is in the SYSTEM mode:

2) I have an easy access to registers through the 'Registers' panel

3) There is a part of OMAP-L138 datasheet which shows the memory map of PSC0 and PSC1 modules:

4) This is a memory view of PSC0 registers:

5) This is a memory view of PSC1 registers:

6) This is a screenshot of the memory map in my CCS project:

It looks equally for PSC0 and PSC1 parts of memory. If the processor tries to write in PSC1 registers it falls into a trap.

Of course, I need all of them. For example, to work with GPIO I need an access to PSC1 and GPIO registers set. But I haven't got it!

I've tried to do it before and I found out that this library is incompatible with SYS/BIOS (I didn't get into main() function and even couldn't stop an execution of the code).

So I guess the right way is the injection into my project the source file boot.asm from bios_6_42_03_35\packages\ti\targets\arm\rtsarm\ location and correction it.

I tried to do that but it was unsuccessful: the project has its own definitions from thr same file which was included as SYS/BIOS library.

As you can see, the problem is a library from SYS/BIOS which is called boot.oe9.

I hope if I can remove it from my project (or even exclude it from the build) I'll reach success, but I can't understand how to do it. Any ideas?

Hi Tankist,

You have to enable the KICK registers before going to access the SYSCONFIG registers.

C:\ti\OMAPL138_StarterWare_1_10_04_01\system_config\armv5\omapl138\startup.c

/* Disable write-protection for registers of SYSCFG module. */
SysCfgRegistersUnlock();

//Shankari : Access all the required registers here

/* Enable write-protection for registers of SYSCFG module. */
SysCfgRegistersLock();