diff --git a/initial-xv6/README.md b/initial-xv6/README.md
index 205cb27..510585f 100644
--- a/initial-xv6/README.md
+++ b/initial-xv6/README.md
@@ -59,6 +59,32 @@ Using gdb (the debugger) may be helpful in understanding code, doing code
 traces, and is helpful for later projects too. Get familiar with this fine
 tool!
 
+# Running Tests
 
+Running tests for your system call is easy. Just do the following from
+inside the `initial-xv6` directory:
 
+```sh
+prompt> ./test-getreadcounts.sh
+```
 
+If you implemented things correctly, you should get some notification
+that the tests passed. If not ...
+
+The tests assume that xv6 source code is found in the `src/` subdirectory.
+If it's not there, the script will complain.
+
+The test script does a one-time clean build of your xv6 source code
+using a newly generated makefile called `Makefile.test`. You can use
+this when debugging (assuming you ever make mistakes, that is), e.g.:
+
+```sh
+prompt> make -f Makefile.test qemu-nox
+```
+
+You can suppress the repeated building of xv6 in the tests with the
+`-s` flag. This should make repeated testing faster:
+
+```sh
+prompt> ./test-getreadcounts.sh -s
+```
diff --git a/tester/README.md b/tester/README.md
index 71f29a2..069bced 100644
--- a/tester/README.md
+++ b/tester/README.md
@@ -20,6 +20,11 @@ The files needed to describe a test number `n` are:
 - `n.pre` (optional): Code to run before the test, to set something up
 - `n.post` (optional): Code to run after the test, to clean something up
 
+There is also a single file called `pre` which gets run once at the 
+beginning of testing; this is often used to do a more complex build
+of a code base, for example. To prevent repeated time-wasting pre-test
+activity, suppress this with the `-s` flag (as described below).
+
 In most cases, a wrapper script is used to call `run-tests.sh` to do the
 necessary work.
 
@@ -29,4 +34,13 @@ The options for `run-tests.sh` include:
 * `-t n` (run only test `n`)
 * `-c` (continue even after a test fails)
 * `-d` (run tests not from `tests/` directory but from this directory instead)
+* `-s` (suppress running the one-time set of commands in `pre` file)
+
+There is also another script used in testing of `xv6` projects, called
+`run-xv6-command`. This is an `expect` script which launches the qemu
+emulator and runs the relevant testing command in the xv6 environment
+before automatically terminating the test. It is used by the `run-tests.sh`
+script as described above and thus not generally called by users directly.
+
+