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From: Antoine Mathys <barsamin@gmail.com>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, paul@codesourcery.com
Subject: [Qemu-devel] [PATCH 3/4] hw/ds1338.c: ensure OSF can only be cleared
Date: Sun, 02 Dec 2012 18:19:59 +0100	[thread overview]
Message-ID: <50BB8DBF.5030505@gmail.com> (raw)

Per the datasheet, the OSF bit in the control register can only be 
cleared. Attempts to set it have no effect. Implement this.

Signed-off-by: Antoine Mathys <barsamin@gmail.com>
---
  hw/ds1338.c |    7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/ds1338.c b/hw/ds1338.c
index 1fb152e..f3c6bc5 100644
--- a/hw/ds1338.c
+++ b/hw/ds1338.c
@@ -160,7 +160,12 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data)
          }
          s->offset = qemu_timedate_diff(&now);
      } else if (s->ptr == 7) {
-        /* Control register. Currently ignored.  */
+        /* Control register. */
+
+        /* Attempting to write the OSF flag to logic 1 leaves the
+           value unchanged. */
+        data = (data & 0xDF) | (data & s->nvram[s->ptr] & 0x20);
+
          s->nvram[s->ptr] = data;
      } else {
          s->nvram[s->ptr] = data;
-- 
1.7.10.4

             reply	other threads:[~2012-12-02 17:20 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-02 17:19 Antoine Mathys [this message]
2012-12-04 17:58 ` [Qemu-devel] [PATCH 3/4] hw/ds1338.c: ensure OSF can only be cleared Peter Maydell

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