Add a few tips.

diff --git a/debug/README.md b/debug/README.md
index 2be795b870baa1f327d3251ac376d21aeaa5ece8..3fa43c767a4e786c9c7a3fa46b9eedbdd84a93b0 100644 (file)
--- a/debug/README.md
+++ b/debug/README.md
@@ -1,3 +1,15 @@
 Debugging requires many of a system components to all work together.  The goal
 is to collect some tests that test gdb with spike, and gdb talking to real
 hardware through openocd.
+
+Debug Tips
+
+You can run just a single test by specifying <class>.<function> on the command
+line, eg: `./gdbserver.py --spike --cmd $RISCV/bin/spike
+SimpleRegisterTest.test_s0`.
+Once that test has failed, you can look at gdb.log and (in this case) spike.log
+to get an idea of what might have gone wrong.
+
+You can see what spike is doing by add `-l` to the spike command, eg.:
+`./gdbserver.py --spike32 --cmd "$RISCV/bin/spike -l"
+DebugTest.test_breakpoint`. (Then look at spike.log.)