I am working on smp_prime code of ARM - A9. And a i want to use that code for cortex A7.
But after making changes like setting smp bit in ACTLR, Making the memory region device and non coherent- then if i enable the MMU bit from system control register. ARM cortex A7 crashes.
Please give me answer of following questions.
1) Is there any huge bit manipulation required to use same code of A9 for A7 ?
2) What is correct way of enabling MMU ?
Hi,
One resource I can recommend for MMU programming is to look in the DS-5 examples/ directory and look at the file RTX5_examples.zip
This zip file has the RTX5 RTOS with supporting code for both Cortex-A9 and Cortex-A7. It has good examples of how to setup and enable the MMU and can run on the FVPs included in DS-5 so you can easily try code with both Cortex-A9 and Cortex-A7 and compare.
If you are just looking to move the smp_primes example from Cortex-A9 to Cortex-A7 I can help. Please post which compiler you are using as there are examples for Arm Compiler 5, Arm Compiler 6, and gcc and any changes you made.
Thanks,
Jason
Thanks for your reply..
I am using x-tool-linux-4-9-armv7a-472-hf toolchain for compiling and building image.
i will check the RTX5 example and Then, still if i got stuck somewhere i will ask you.
thanks,
VISA
See jason what i did is :
case 1:::
1) I have set TEX=1,C=1,B=1 in TTB section frame.: This is for write allocate and write back
2) I have keep all functions same as A9 just i changed this flags and memory areas with i want as device and shared.
3) Then i enabled MMU along with Branch prediction and Instruction cache.
4) then jump to main.
5) And then from main if i enable data cache arm crashes.
6) And also if enable Data cache i got junk characters on screen.
case :::
1) if i set TEX as 0, C=1, B=0 then all programs works fine.
Problem is it is write through and i don't want this.
I want my code for 0x80000000 should be cacheble and remaining normal.
Tell me how can i get this
hii jason,
I checked it. RTX code files is not for smp.
I am looking for smp mmu setup.
please if you come to know anything about smp mmu setup please tell me.
Thank you..