1 files changed, 26 insertions, 0 deletions

diff --git a/README.md b/README.md
index 0988e6e..dbc90c0 100644
--- a/README.md
+++ b/README.md
@@ -76,4 +76,30 @@ make run ROM_SRC=roms/audio.rom CONFIG="-DAUDIO_HIFI"
 make run ROM_SRC=roms/audio.rom CONFIG="-DAUDIO_LOFI"
 ```
 
+### Text layer
+
+When writing text to the screen (for example using the console device) the text
+will be drawn by default on the foreground layer. This can be controlled by
+setting the `TEXT_MODE` option to 0 for foreground mode or 1 for background
+mode.
+
+```
+make run CONFIG="-DTEXT_MODE=1"
+```
+
+### Performance metrics
+
+To enable profiling, the `PROF_ENABLE` macro can be used. This will display the
+cycle count for input handling (INPUT), loop uxn evaluation (EVAL), screen
+buffer flip (FLIP) and audio mixing (MIX). If `PROF_ENABLE` is set to 0, the
+current frame numbers will be displayed, if set to 1, the maximum cycle count
+for each section will be used instead. Enabling profiling can have a small
+performance impact, so these numbers may not be 100% accurate, but should give
+a good indication. Using `PROF_SHOW_X` and `PROF_SHOW_Y` we can control at which
+tile the cycle count text will be located.
+
+```
+make run CONFIG="-DPROF_ENABLE=0 -DPROF_SHOW_Y=8 -DPROF_SHOW_X=8"
+```
+
 [noodle]: https://wiki.xxiivv.com/site/noodle.html