ARM: 5841/1: a driver for on-chip ETM and ETB

This driver implements support for on-chip Embedded Tracing Macrocell and
Embedded Trace Buffer. It allows to trigger tracing of kernel execution flow
and exporting trace output to userspace via character device and a sysrq
combo.

Trace output can then be decoded by a fairly simple open source tool [1]
which is already sufficient to get the idea of what the kernel is doing.

[1]: http://github.com/virtuoso/etm2human

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 1a6f70e52921..ff54c23d085e 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -83,6 +83,14 @@ config DEBUG_ICEDCC
           It does include a timeout to ensure that the system does not
           totally freeze when there is nothing connected to read.
 
+config OC_ETM
+        bool "On-chip ETM and ETB"
+        select ARM_AMBA
+        help
+          Enables the on-chip embedded trace macrocell and embedded trace
+          buffer driver that will allow you to collect traces of the
+          kernel code.
+
 config DEBUG_DC21285_PORT
         bool "Kernel low-level debugging messages via footbridge serial port"
         depends on DEBUG_LL && FOOTBRIDGE