ARM Technical Support Knowledge Articles

How is DS-5 Kernel only Trace configured?

Applies to: DS-5

Answer

In DS-5 the “Debug and Kernel-only trace” operation uses trace ranges to restrict trace capture to kernel space. (Note when using a PTM, there may be some excess trace collected when the core leaves the selected region).

Generally kernels are built with a “3G/1G user/kernel space split”. This means trace will be captured for code running from address 0xC0000000 to 0xFFFFFFFF. However it is possible for kernels to be built with other address ranges.

For example the default ARM Versatile Express and FreeScale IMX35 kernels are built using a 2G/2G user/kernel space split, with the kernel being loaded at 0x80000000.

In DS5.5 onwards platform support for these targets is pre-configured to collect trace from 0x80000000 upwards. This is done using .addTraceRange(start,end) function calls in DS-5's configuration database platform support files.

If you modify the default kernel start address then DS-5’s trace range configuration will also need to be adapted. Please contact support-sw@arm.com for more details on how to do this.

Article last edited on: 2011-05-09 09:06:35

Rate this article

[Bad]
|
|
[Good]
Disagree? Move your mouse over the bar and click

Did you find this article helpful? Yes No

How can we improve this article?

Link to this article
Copyright © 2011 ARM Limited. All rights reserved. External (Open), Non-Confidential