diff options
Diffstat (limited to 'doc/openocd.texi')
| -rw-r--r-- | doc/openocd.texi | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/doc/openocd.texi b/doc/openocd.texi index e04b83c8..c9e48bfa 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -5114,14 +5114,23 @@ ETM support in OpenOCD doesn't seem to be widely used yet. @quotation Issues ETM support may be buggy, and at least some @command{etm config} parameters should be detected by asking the ETM for them. + +ETM trigger events could also implement a kind of complex +hardware breakpoint, much more powerful than the simple +watchpoint hardware exported by EmbeddedICE modules. +@emph{Such breakpoints can be triggered even when using the +dummy trace port driver}. + It seems like a GDB hookup should be possible, -as well as triggering trace on specific events +as well as tracing only during specific states (perhaps @emph{handling IRQ 23} or @emph{calls foo()}). + There should be GUI tools to manipulate saved trace data and help analyse it in conjunction with the source code. It's unclear how much of a common interface is shared with the current XScale trace support, or should be shared with eventual Nexus-style trace module support. + At this writing (September 2009) only ARM7 and ARM9 support for ETM modules is available. The code should be able to work with some newer cores; but not all of them support @@ -5135,7 +5144,10 @@ ETM setup is coupled with the trace port driver configuration. Declares the ETM associated with @var{target}, and associates it with a given trace port @var{driver}. @xref{Trace Port Drivers}. -Several of the parameters must reflect the trace port configuration. +Several of the parameters must reflect the trace port capabilities, +which are a function of silicon capabilties (exposed later +using @command{etm info}) and of what hardware is connected to +that port (such as an external pod, or ETB). The @var{width} must be either 4, 8, or 16. The @var{mode} must be @option{normal}, @option{multiplexted}, or @option{demultiplexted}. @@ -5151,6 +5163,9 @@ what CPU activities are traced. @deffn Command {etm info} Displays information about the current target's ETM. +This includes resource counts from the @code{ETM_CONFIG} register, +as well as silicon capabilities (except on rather old modules). +from the @code{ETM_SYS_CONFIG} register. @end deffn @deffn Command {etm status} |