Annotate overview
While ARM Streamline provides a large variety of target information, sometimes you require extra context to decipher exactly what the target is doing at certain instances. Streamline Annotate provides a facility for you to add this context to Streamline.
The Streamline Annotate feature works in a similar way to printf
, but instead
of console output, annotate statements populate the Log view and place framing overlays
right in the Streamline Timeline view.
Figure 10-1 Annotation overlays

When the user space application writes to the /dev/gator/annotate file, the gator driver marks the recorded annotate-driven output with a timestamp and integrates the recorded data into the Streamline sample and trace capture report.
The annotated text is marked with a thread identifier that keeps the data uncluttered and eliminates the necessity of user mutexes. Writing to the annotate file is handled by the standard C-library functions.
The application code accesses the virtual annotate file using the standard
c-library functions: fopen
, fwrite
, and fflush
.