Thejasiwni Chandrashekar

i.MX 8QuadMax MEK registers

Discussion created by Thejasiwni Chandrashekar on Mar 6, 2019
Latest reply on Mar 7, 2019 by Victor Linnik

we are using the i.MX 8 QuadMax MEK CPU boards. u-boot is compiled using aarch64-poky-linux-gcc. In the standalone hello world application we are trying to read the RMR_EL3 with __asm__("mrs x0,rmr_el3");  with this statement in trace 32 we are seeing following error,

"debug port fail
Debug registers seem to be inaccessible (EDPRSR, DBGAUTHSTATUS, CTRL/STAT)".

Also tried with "RMR registers with __asm__ __volatile__("MRC p15,0,R0,c12,c0,2");" this is giving compilation error 

"{standard input}: Assembler messages:
{standard input}:109: Error: unknown mnemonic `mrc' -- `mrc p15,0,R0,c12,c0,2'"


We are trying this, to know the execution state(32 / 64 bit) of the processor and want to change from 32  to 64 or viceversa. 

Kindly help us in reading this register. Is there any other way to know the execution state and to change the same.  


Appreciate your response at the earliest.