escc: explicitly mark variable containing incoming keyboard character as volatile

Otherwise the compiler may not understand that a read from the assigned buffer
is comming from memory-mapped IO space and fail to update accordingly.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/escc.c b/drivers/escc.c
index 392625e4..d9e19909 100644
--- a/drivers/escc.c
+++ b/drivers/escc.c
@@ -284,7 +284,7 @@ keyboard_dataready(void)
 unsigned char
 keyboard_readdata(void)
 {
-    unsigned char ch;
+    volatile unsigned char ch;
 
     while (!keyboard_dataready()) { }