66ak2e05 hangs when accessing A15 coprocessors

Glyn Jones

Other Parts Discussed in Thread: 66AK2E05

I'm trying to read the SCR from the A15.

    unsigned nsacr, scr;
   __asm__ __volatile__("mrc   p15, 0, %0, c1, c1, 0" : "=r"(scr));
    printf("Secure config register = %x\n", scr);

The same is true for the NSACR:

__asm__ __volatile__("mrc p15, 0, %0, c1, c1, 2" : "=r"(nsacr));
printf("NSACR = 0x%x\n", nsacr);

When I run the above inlined assembly code, the processor hangs.

ARM's ducumentaiton suggests that both should be readable in Secure Mode, and the second should be readable in non-secure mode - how can I tell whether I am in secure mode or not?

If I am not in secure mode, how can I switch to it?

Thanks.

over 10 years ago

0 Raja over 10 years ago

TI__Guru* 81335 points

Hi Glyn,

Welcome to the TI E2E forum. I hope you will find many good answers here and in the TI.com documents and in the TI Wiki Pages (for processor issues). Be sure to search those for helpful information and to browse for the questions others may have asked on similar topics (e2e.ti.com).

Please refer below thread for answer.

http://e2e.ti.com/support/dsp/c6000_multi-core_dsps/f/639/t/345672.aspx

Thank you.

0 Glyn Jones over 10 years ago in reply to Raja

Prodigy 100 points

Thanks for the quick response.

I've looked up the post you suggested, but it doesn't have all the answers I need.

Does the monitor code live in ROM, or is it loaded at boot time by u-boot or the kernel?

Is there a document defining all the secure monitor calls? The snippet shown in the post is for the AM335x, not the 66ak2e05, so how can I know what service IDs exist for the 66?

I have tried writing to the ACR using the above information, but the code now hangs when calling "smc #1"

0 Raja over 10 years ago in reply to Glyn Jones

TI__Guru* 81335 points

Hi Glyn,

The boot monitor code(skern-keystone-evm.bin) is loaded by the u-boot at address 0xc5f0000.

http://processors.wiki.ti.com/index.php/MCSDK_UG_Chapter_Exploring#Boot_Monitor_2

Thank you.

0 Glyn Jones over 10 years ago in reply to Raja

Prodigy 100 points

I've managed to get the secure monitor code loaded - though it is at a different address on the Keystone II to where the documentation suggests it should be.

Is there a document defining all the secure monitor calls? The snippet shown in the post is for the AM335x, not the 66ak2e05, so how can I know what service IDs exist for the 66?

0 Raja over 10 years ago in reply to Glyn Jones

TI__Guru* 81335 points

Hi Glyn,

Is there a document defining all the secure monitor calls?

Are you working on secure boot?

The snippet shown in the post is for the AM335x, not the 66ak2e05, so how can I know what service IDs exist for the 66?

Please update the post referenced here.

Thank you

0 Glyn Jones over 10 years ago in reply to Raja

Prodigy 100 points

The discussion I referenced is :

http://e2e.ti.com/support/dsp/c6000_multi-core_dsps/f/639/t/345672.aspx

I am porting the QNX kernel to the Keystone 2.
I need to be able to modify various registers in secure mode at particular points during the startup.

Using the "mcr" assembly mnemonics wither hangs or fails to write to the register. QNX code on other ARM15 based boarda (eg OMAP 5432) uses secure monitor calls, so I assume I need to use these, and am trying to get the API into the secure monitor that allows me to perform the same functions, such as writing to the AUXCR.

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66ak2e05 hangs when accessing A15 coprocessors