How to enter privilege mode?

vipul mahajan

Other Parts Discussed in Thread: AM1808

Hello,

I am trying to use a UART test code of AM1808 on my custom board. I am unable to set pin mux as it requires to be in privilege mode. How can I set privilege mode and do all my work in privilege mode. I am developing code in C using CCS.

over 14 years ago

0 Paul.Yin over 14 years ago

TI__Genius 14405 points

Vipul,

Basically you need to modify the value of the CPSR registers, in particular the mode bits CPSR[4:0]. Please see the ARM9 EJS data manual.

You can do this in CCS or in an assembly file. I am not sure how to do this in C code. Will find that out for you.

regards,

Paul

0 jc-ti over 14 years ago

TI__Mastermind 27585 points

See the links in this wiki which show how to keep the ARM in supervisor mode: http://processors.wiki.ti.com/index.php/OMAP-L138_Bootloader#ARM_Supervisor_vs_User_mode

0 vipul mahajan over 14 years ago in reply to Paul.Yin

Intellectual 900 points

Paul.Yin,

I have got the asm file which does so but unable to include that in my project. Please help in including the asm file in ccs project or provide the C code which does so in CCS.

0 vipul mahajan over 14 years ago in reply to jc-ti

Intellectual 900 points

jc-ti,

Thanks for the link. I got the modified boot.asm file but i don't know how to add that in my project. Please help.

0 vipul mahajan over 14 years ago in reply to jc-ti

Intellectual 900 points

Thanks a lot for the link. I just pasted boot.asm in my project folder & it worked. Thanks a lot.

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How to enter privilege mode?