README: document the requirements for CONFIG_SYS_HZ

CONFIG_SYS_HZ must be 1000, and get_timer() must therefore return ms.
Document this.

README text provided by Tom Rini.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>

diff --git a/README b/README
index 1d5182825241f42e8c8256daf1f7c88aec2c90ec..57010161f57f5a719430b06a64b75fd27980b16d 100644 (file)
--- a/README
+++ b/README
@@ -496,6 +496,13 @@ The following options need to be configured:
                exists, unlike the similar options in the Linux kernel. Do not
                set these options unless they apply!
 
                exists, unlike the similar options in the Linux kernel. Do not
                set these options unless they apply!
 

+- CPU timer options:
+               CONFIG_SYS_HZ
+
+               The frequency of the timer returned by get_timer().
+               get_timer() must operate in milliseconds and this CONFIG
+               option must be set to 1000.
+

 - Linux Kernel Interface:
                CONFIG_CLOCKS_IN_MHZ
 
 - Linux Kernel Interface:
                CONFIG_CLOCKS_IN_MHZ