- Factoring of auto.c
- Implementation of fallback/normal support for the amd solo board
- Minor bugfix in romcc
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@867 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
diff --git a/src/pc80/mc146818rtc_early.c b/src/pc80/mc146818rtc_early.c
new file mode 100644
index 0000000..1d268f0
--- /dev/null
+++ b/src/pc80/mc146818rtc_early.c
@@ -0,0 +1,84 @@
+#include <pc80/mc146818rtc.h>
+#include <part/fallback_boot.h>
+
+static unsigned char cmos_read(unsigned char addr)
+{
+ outb(addr, RTC_BASE_PORT + 0);
+ return inb(RTC_BASE_PORT + 1);
+}
+
+static void cmos_write(unsigned char val, unsigned char addr)
+{
+ outb(addr, RTC_BASE_PORT + 0);
+ outb(val, RTC_BASE_PORT + 1);
+}
+
+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)
+{
+ unsigned char addr;
+ unsigned long sum, old_sum;
+ sum = 0;
+ /* Comput the cmos checksum */
+ for(addr = LB_CKS_RANGE_START; addr <= LB_CKS_RANGE_END; addr++) {
+ sum += cmos_read(addr);
+ }
+ sum = (sum & 0xffff) ^ 0xffff;
+
+ /* Read the stored checksum */
+ old_sum = cmos_read(LB_CKS_LOC) << 8;
+ old_sum |= cmos_read(LB_CKS_LOC+1);
+
+ return sum == old_sum;
+}
+
+
+static int do_normal_boot(void)
+{
+ unsigned char byte;
+
+ if (cmos_error() || !cmos_chksum_valid()) {
+ unsigned char byte;
+ /* There are no impossible values, no cheksums 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 |= 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 */
+ }
+
+ /* Are we already at the max count? */
+ if ((byte >> 4) < MAX_REBOOT_CNT) {
+ byte += 1 << 4; /* No, add 1 to the count */
+ }
+ else {
+ byte &= 0xfc; /* Yes, put in fallback mode */
+ }
+
+ /* Is this the first boot? */
+ if ((byte >> 4) <= 1) {
+ byte = (byte & 0xfc) | ((byte & 1) << 1); /* yes, shift the boot bits */
+ }
+
+ /* Save the boot byte */
+ cmos_write(byte, RTC_BOOT_BYTE);
+
+ return ((byte >> 4) < MAX_REBOOT_CNT);
+}