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authorStefan Reinauer <stefan.reinauer@coreboot.org>2012-04-27 02:31:28 +0200
committerStefan Reinauer <stefan.reinauer@coreboot.org>2012-04-27 19:23:16 +0200
commitae5e11d7cd7484343d277fb454fb19fdff34730d (patch)
tree231aede3dcf80242a4e68e2b4268835f4bf1c5c6 /src/drivers/pc80/mc146818rtc_early.c
parentaee1869fcf6c5eb1616f8c5c5a446c2b2de693e8 (diff)
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Move top level pc80 directory to drivers/
There is no reason for this to be a top level directory. Some stuff from lib/ should also be moved to drivers/ Change-Id: I3c2d2e127f7215eadead029cfc7442c22b26814a Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-on: http://review.coreboot.org/939 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Diffstat (limited to 'src/drivers/pc80/mc146818rtc_early.c')
-rw-r--r--src/drivers/pc80/mc146818rtc_early.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/src/drivers/pc80/mc146818rtc_early.c b/src/drivers/pc80/mc146818rtc_early.c
new file mode 100644
index 000000000000..0652f27c47ff
--- /dev/null
+++ b/src/drivers/pc80/mc146818rtc_early.c
@@ -0,0 +1,104 @@
+#include <stdint.h>
+#include <pc80/mc146818rtc.h>
+#include <fallback.h>
+#if CONFIG_USE_OPTION_TABLE
+#include "option_table.h"
+#endif
+
+#ifndef CONFIG_MAX_REBOOT_CNT
+#error "CONFIG_MAX_REBOOT_CNT not defined"
+#endif
+#if CONFIG_MAX_REBOOT_CNT > 15
+#error "CONFIG_MAX_REBOOT_CNT too high"
+#endif
+
+static int cmos_error(void)
+{
+ unsigned char reg_d;
+ /* See if the cmos error condition has been flagged */
+ reg_d = cmos_read(RTC_REG_D);
+ return (reg_d & RTC_VRT) == 0;
+}
+
+static int cmos_chksum_valid(void)
+{
+#if CONFIG_USE_OPTION_TABLE
+ unsigned char addr;
+ u16 sum, old_sum;
+ sum = 0;
+ /* Compute the cmos checksum */
+ for(addr = LB_CKS_RANGE_START; addr <= LB_CKS_RANGE_END; addr++) {
+ sum += cmos_read(addr);
+ }
+
+ /* Read the stored checksum */
+ old_sum = cmos_read(LB_CKS_LOC) << 8;
+ old_sum |= cmos_read(LB_CKS_LOC+1);
+
+ return sum == old_sum;
+#else
+ return 0;
+#endif
+}
+
+
+static inline int last_boot_normal(void)
+{
+ unsigned char byte;
+ byte = cmos_read(RTC_BOOT_BYTE);
+ return (byte & (1 << 1));
+}
+
+static inline int do_normal_boot(void)
+{
+ unsigned char byte;
+
+ if (cmos_error() || !cmos_chksum_valid()) {
+ /* There are no impossible values, no checksums so just
+ * trust whatever value we have in the the cmos,
+ * but clear the fallback bit.
+ */
+ byte = cmos_read(RTC_BOOT_BYTE);
+ byte &= 0x0c;
+ byte |= CONFIG_MAX_REBOOT_CNT << 4;
+ cmos_write(byte, RTC_BOOT_BYTE);
+ }
+
+ /* The RTC_BOOT_BYTE is now o.k. see where to go. */
+ byte = cmos_read(RTC_BOOT_BYTE);
+
+ /* Are we in normal mode? */
+ 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 */
+ }
+
+ /* Save the boot byte */
+ cmos_write(byte, RTC_BOOT_BYTE);
+
+ return (byte & (1<<1));
+}
+
+unsigned read_option_lowlevel(unsigned start, unsigned size, unsigned def)
+{
+#if CONFIG_USE_OPTION_TABLE
+ unsigned byte;
+ byte = cmos_read(start/8);
+ return (byte >> (start & 7U)) & ((1U << size) - 1U);
+#else
+ return def;
+#endif
+}