[coreboot-gerrit] New patch to review for coreboot: drivers/pc80: Ensure recovery mode always boots fallback image

[Timothy Pearson]

Timothy Pearson ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/12289

-gerrit

commit c49d7f9bf46bee43f9fcf691762959dc82b1876a
Author: Timothy Pearson 
Date:   Sun Nov 1 02:13:17 2015 -0600

drivers/pc80: Ensure recovery mode always boots fallback image

The current fallback / failed boot count checks only look at the
    value of last_boot when determining whether to execute the
    normal or fallback image.  Furthermore, the normal boot bit is
    unconditionally set if the failed boot count has not exceeded
    its threshold, thereby overriding a request from the user to
    boot into fallback mode if the user does not also set the failed
    boot count above the failure threshold.

Only check the failed boot count if the normal boot bit is set
    in nvram.

Change-Id: I753ae9f0710c524875a85354ac2547df0c305569
    Signed-off-by: Timothy Pearson 
---
 src/drivers/pc80/mc146818rtc_early.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/drivers/pc80/mc146818rtc_early.c b/src/drivers/pc80/mc146818rtc_early.c
index 421af2f..9861c29 100644
--- a/src/drivers/pc80/mc146818rtc_early.c
+++ b/src/drivers/pc80/mc146818rtc_early.c
@@ -72,18 +72,20 @@ static inline __attribute__((unused)) int do_normal_boot(void)
    	if (byte & 1)
    		byte &= 0x0f; /* yes, clear the boot count */

-	/* Properly set the last boot flag */
-	byte &= 0xfc;
-	if ((byte >> 4) < CONFIG_MAX_REBOOT_CNT) {
-		byte |= (1<<1);
-	}
-
-	/* Are we already at the max count? */
-	if ((byte >> 4) < CONFIG_MAX_REBOOT_CNT) {
-		byte += 1 << 4; /* No, add 1 to the count */
-	}
-	else {
-		byte &= 0xfc;	/* Yes, put in fallback mode */
+	if (byte & 1) {
+		/* Properly set the last boot flag */
+		byte &= 0xfc;
+		if ((byte >> 4) < CONFIG_MAX_REBOOT_CNT) {
+			byte |= (1<<1);
+		}
+
+		/* Are we already at the max count? */
+		if ((byte >> 4) < CONFIG_MAX_REBOOT_CNT) {
+			byte += 1 << 4; /* No, add 1 to the count */
+		}
+		else {
+			byte &= 0xfc;	/* Yes, put in fallback mode */
+		}
    }

/* Save the boot byte */