Starting with the v5.1 kernel cycle compiling the perf tools (on and off target) requires the addition of a new CORESIGHT=1 command line flag.

See the following commit for details:

1c3b28fd7ae8 ("perf coresight: Do not test for libopencsd by default")

Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org --- HOWTO.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/HOWTO.md b/HOWTO.md index 551b085c9c78..3b93b3d392aa 100644 --- a/HOWTO.md +++ b/HOWTO.md @@ -21,10 +21,10 @@ supplemented with modifications to the CoreSight framework and drivers to be usable by the Perf core. The remaining out of tree patches are being upstreamed incrementally.

-From there compiling the perf tools with `make -C tools/perf` will yield a -`perf` executable that will support CoreSight trace collection. Note that if -traces are to be decompressed *off* target, there is no need to download and -compile the openCSD library (on the target). +From there compiling the perf tools with `make -C tools/perf CORESIGHT=1` will +yield a `perf` executable that will support CoreSight trace collection. Note +that if traces are to be decompressed *off* target, there is no need to download +and compile the openCSD library (on the target).

Before launching a trace run a sink that will collect trace data needs to be identified. All CoreSight blocks identified by the framework are registed in @@ -306,7 +306,7 @@ and needs to be installed on a system prior to compilation. Information about the status of the openCSD library on a system is given at compile time by the perf tools build script:

- linaro@t430:~/linaro/linux-kernel$ make VF=1 -C tools/perf + linaro@t430:~/linaro/linux-kernel$ make CORESIGHT=1 VF=1 -C tools/perf Auto-detecting system features: ... dwarf: [ on ] ... dwarf_getlocations: [ on ]