Fix variable CPU clock for MPC859/866 systems for low CPU clocks
diff --git a/doc/README.MPC866 b/doc/README.MPC866
index 1464a40..42abac8 100644
--- a/doc/README.MPC866
+++ b/doc/README.MPC866
@@ -12,6 +12,10 @@
CPUCLK_MAX limits, the specified value is used. Otherwise, the
default CPU clock value is set.
+Please make sure you understand what you are doing, and understand
+the restrictions of your hardware (board, processor). For example,
+ethernet will stop working for CPU clock frequencies below 25 MHz.
+
Please note that for now the new clock-handling code has been enabled
for the TQM866M board only, even though it should be pretty much
common for other MPC859 / MPC866 based boards also. Our intention
