We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
HI All,
I am trying to use FREE RTOS in cortex R5 dual core MCU.
Initially the MCU is in Supervisor mode. But in main function, i want to be a processor mode will be in system mode(0x1F).
But i do not find any instruction how to switch from supervisor mode(0x13) to system mode(0x1F).
Why we need to switch from supervisor mode to system mode if both are working in privilege mode because for the unitization of the RTOS, scheduler should be in system mode.
Can any one please tell me how to switch from supervisor mode to system mode.
I have tried to switch but the system will be reset automatically after change in system mode.
have see the mode in CPSR register.
Thanks and regard
Pankaj verma
HI Synnott,
Yes you are right and i have tried below code as per your suggestion.
It is jump to the supervisor mode to system mode by using below instruction.
.def _CPU_system_mode_Switch .asmFunc_CPU_system_mode_Switch
MOV R1, LR MOV R2, SP MRS r0, CPSR //read cpsr into r0 orr r0, r0, #0x1f //set mode to SYS MSR cpsr, r0 //write r0 back to cpsr MOV LR, R1 MOV SP, R2 bx lr //return .endasmfunc
Is it correct?
I will also try your code.
Can you tell me that, if a application jump to system mode to supervisor mode at any time and vise versa . It will not effect to running application and RTOS behavior's.
Thanks for your great help, Have a nice day.
Pankaj Verma
The code looks correct to me, but as I said, I don't believe this is really what you want to do...
Your application should run in SYS mode (ideally USR mode), and the RTOS in SVC mode, with independent stacks. The RTOS will manage switching between applications.
Regards. Ronan