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How to enter USR mode from SVC mode?

Note: This was originally posted on 1st August 2011 at http://forums.arm.com

I changed CPSR to 0x1D0(which means USR mode )in SVC mode in cortex-a8 platform(freescale imx51), but a perfetch_error occured, the PC hung at 0x0c. Could anybody help me figure this issue out, please?
OR anybody has some code some hwo to enter USR mode from SVC mode?

Best Regards
Jerry

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Christophe Beausoleil over 12 years ago

Note: This was originally posted on 1st August 2011 at http://forums.arm.com

Hi Jerry,

Here is how I do for Cortex-R4F :

     mrs r1, cpsr
     orr r1, r1, #0x0010
     bic r1, r1, #0x000F
     msr cpsr_c, r1

Hope it helps

Best regards

Christophe
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Christophe Beausoleil over 12 years ago

Note: This was originally posted on 1st August 2011 at http://forums.arm.com

Hi Jerry,

Here is how I do for Cortex-R4F :

     mrs r1, cpsr
     orr r1, r1, #0x0010
     bic r1, r1, #0x000F
     msr cpsr_c, r1

Hope it helps

Best regards

Christophe
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