AM335x EVM SK NFS Debugging Help

Tim Roberts80

A bit of a warning to start this off, I've never developed in an embedded Linux environment before. Beginner steps are appreciated.

My Setup:
TI AM335x EVM Starter Kit
Ubuntu 12.04
CCS V6
Linux SDK 07.00.00.00

I am able to program and debug on the EVM SK without an SD card inserted using the TI XDS100v2 USB debug probe emulator.

I am able to successfully boot the EVM SK from NFS.

I am able to establish an SSH connection within CCS V6 to the EVM SK.

I have set up my CCS project to be in the target NFS /home/root directory. For now I'm just trying to get a simple hello world program up to verify I can debug the NFS.

I am using a working target configuration file (it worked without the SD card inserted at any rate, and I didn't see any options that looked relevant to change).

When I try to debug I get Error -1204 @ 0x3D5B: Unable to access the DAP. Reset the device, and retry the operation.

I'm using Emulation package 5.1.507.0

What do I need to do to resolve this issue? It seems like its resolvable, but I haven't found anything that's in the beginner-ish range.

Thanks in advance.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Moving this to the CCS forum.

0 Ki over 10 years ago

TI__Guru**** 467991 points

Hi Tim,

Tim Roberts80 said:
I am using a working target configuration file (it worked without the SD card inserted at any rate, and I didn't see any options that looked relevant to change).

Are you using a GEL startup file with your target configuration? One gotcha for people trying to debug a target running embedded linux is using a startup GEL file that will blow away the initialization that the bootloader did and put the target in a bad state for the debugger to access.

0 Tim Roberts80 over 10 years ago in reply to Ki

Intellectual 470 points

Hi Ki,

Thanks for the reply. Again since I'm new to the CCS environment, how would I go about checking/setting this? In my project explorer I don't see any GEL files.

Now that you mention it though, I see a startup_ARMCA8.s assembly file that is Init code routine for A8 cores and Linaro baremetal. Will I need this on top of the GEL file?

Tim

0 Ki over 10 years ago in reply to Tim Roberts80

TI__Guru**** 467991 points

To see if there are any GEL files loaded, see:

http://processors.wiki.ti.com/index.php/GEL

If you do see one, shut down the debugger and remove it from the target configuration and try again.

To see where startup GEL files are defined, see slide 15 of: http://processors.wiki.ti.com/index.php/CCS_Modules_Library#Target_Configurations

0 Tim Roberts80 over 10 years ago in reply to Ki

Intellectual 470 points

Hi Ki,

I went through my target configuration and found 2 GEL files. One at the CS_DAP_DebugSS lvel and another in theCSS_DAP_DebugSS->ModenaSS->CortxA8 level. I've tried bypassing all combinations of these, but the message that it cannot access the DAP still appears.

Is bypassing not enough? Do I need to remove it or specify a new GEL file?

0 Tim Roberts80 over 10 years ago in reply to Tim Roberts80

Intellectual 470 points

Just as an update I tried removing them as well from the configuration with the same result.

0 Tim Roberts80 over 10 years ago in reply to Tim Roberts80

Intellectual 470 points

Are there any other ideas about how to get my debugger working?

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AM335x EVM SK NFS Debugging Help