1 files changed, 25 insertions, 3 deletions
diff --git a/README.md b/README.md
index 31efd9f..52dcf83 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,28 @@ the XiLinx tools work properly without that.  So:
 /opt/Xilinx/14.7/ISE_DS/common/bin/lin64/xlcm -manage
 ```
 
-In theory, we can run this GUI stuff under `Xvfb` in Docker.
-Debugging this will probably require exporting the `Xvfb_screen0` file
-via a volume mount.
+Kludges too awful to mention
+----------------------------
+
+The file `finish.png` is for the `visgrep` tool from the `xautomation`
+package.  It sorta mostly kinda works as a mechanism for detecting
+that we've gotten to the end of the XiLinx installation process.  I
+haven't gotten it to work quite as it says on the tin, but something like:
+
+```
+while true
+do
+    xwdtopnm 2>/dev/null framebuf/Xvfb_screen0 | pnmtopng >framebuf/screen.png
+    if test -n "$(visgrep framebuf/screen.png finish.png finish.png)"
+    then
+        break
+    fi
+done
+```
+
+For reasons that I don't understand, `visgrep` returns failure (exit
+status 1) even when it finds the pattern, even though the manual says
+it's not supposed to do that.   Dunno why.  Ancient code.  Whatever.
+
+In practice, this is so nasty that I'm seriously tempted just to wait
+half an hour then blindly click on where the finish button should be.