[src/trunk]: src/sys/arch/arm/broadcom discard initial numbers from rng, broa...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3b29666f9b6f
branches:  trunk
changeset: 784512:3b29666f9b6f
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Wed Jan 30 11:52:54 2013 +0000

description:
discard initial numbers from rng, broadcom says they are "less random"

diffstat:

 sys/arch/arm/broadcom/bcm2835_rng.c |  7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diffs (28 lines):

diff -r 49956342bcc5 -r 3b29666f9b6f sys/arch/arm/broadcom/bcm2835_rng.c
--- a/sys/arch/arm/broadcom/bcm2835_rng.c       Wed Jan 30 10:10:29 2013 +0000
+++ b/sys/arch/arm/broadcom/bcm2835_rng.c       Wed Jan 30 11:52:54 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bcm2835_rng.c,v 1.1 2013/01/25 00:04:06 jmcneill Exp $ */
+/*     $NetBSD: bcm2835_rng.c,v 1.2 2013/01/30 11:52:54 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2012 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bcm2835_rng.c,v 1.1 2013/01/25 00:04:06 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bcm2835_rng.c,v 1.2 2013/01/30 11:52:54 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -109,6 +109,9 @@
        callout_init(&sc->sc_tick, CALLOUT_MPSAFE);
        callout_setfunc(&sc->sc_tick, bcmrng_tick, sc);
 
+       /* discard initial numbers, broadcom says they are "less random" */
+       bus_space_write_4(sc->sc_iot, sc->sc_ioh, RNG_STATUS, 0x40000);
+
        /* enable rng */
        ctrl = bus_space_read_4(sc->sc_iot, sc->sc_ioh, RNG_CTRL);
        ctrl |= RNG_CTRL_EN;