---
Makefile | 4 +
rtc-test.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 205 insertions(+), 0 deletions(-)
create mode 100644 rtc-test.c
diff --git a/Makefile b/Makefile
index 301c75e..838cb01 100644
--- a/Makefile
+++ b/Makefile
@@ -215,6 +215,10 @@ $(qga-obj-y) qemu-ga.o: $(QGALIB_GEN) $(GENERATED_HEADERS)
qemu-ga$(EXESUF): qemu-ga.o $(qga-obj-y) $(qapi-obj-y) $(tools-obj-y)
$(qobject-obj-y) $(version-obj-y) $(QGALIB_OBJ)
+libqtest.o: libqtest.c
+
+rtc-test$(EXESUF): rtc-test.o libqtest.o
+
QEMULIBS=libhw32 libhw64 libuser libdis libdis-user
clean:
diff --git a/rtc-test.c b/rtc-test.c
new file mode 100644
index 0000000..01e4e49
--- /dev/null
+++ b/rtc-test.c
@@ -0,0 +1,201 @@
+#include "libqtest.h"
+
+#include <glib.h>
+#include <stdio.h>
+#include <string.h>
+
+static uint8_t base = 0x70;
+
+static int bcd2dec(int value)
+{
+ return (((value >> 4) & 0x0F) * 10) + (value & 0x0F);
+}
+
+#if 0
+static int dec2bcd(int value)
+{
+ return ((value / 10) << 4) | (value % 10);
+}
+#endif
+
+static uint8_t cmos_read(uint8_t reg)
+{
+ outb(base + 0, reg);
+ return inb(base + 1);
+}
+
+static void cmos_write(uint8_t reg, uint8_t val)
+{
+ outb(base + 0, reg);
+ outb(base + 1, val);
+}
+
+static int tm_cmp(struct tm *lhs, struct tm *rhs)
+{
+ time_t a, b;
+ struct tm d1, d2;
+
+ memcpy(&d1, lhs, sizeof(d1));
+ memcpy(&d2, rhs, sizeof(d2));
+
+ a = mktime(&d1);
+ b = mktime(&d2);
+
+ if (a < b) {
+ return -1;
+ } else if (a > b) {
+ return 1;
+ }
+
+ return 0;
+}
+
+#if 0
+static void print_tm(struct tm *tm)
+{
+ printf("%04d-%02d-%02d %02d:%02d:%02d\n",
+ tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_gmtoff);
+}
+#endif
+
+static void cmos_get_date_time(struct tm *date)
+{
+ int base_year = 2000, hour_offset;
+ int sec, min, hour, mday, mon, year;
+ time_t ts;
+ struct tm dummy;
+
+ sec = cmos_read(0x00);
+ min = cmos_read(0x02);
+ hour = cmos_read(0x04);
+ mday = cmos_read(0x07);
+ mon = cmos_read(0x08);
+ year = cmos_read(0x09);
+
+ if ((cmos_read(0x0B) & 4) == 0) {
+ sec = bcd2dec(sec);
+ min = bcd2dec(min);
+ hour = bcd2dec(hour);
+ mday = bcd2dec(mday);
+ mon = bcd2dec(mon);
+ year = bcd2dec(year);
+ hour_offset = 80;
+ } else {
+ hour_offset = 0x80;
+ }
+
+ if ((cmos_read(0x0B) & 2) == 0) {
+ if (hour >= hour_offset) {
+ hour -= hour_offset;
+ hour += 12;
+ }
+ }
+
+ ts = time(NULL);
+ localtime_r(&ts, &dummy);
+
+ date->tm_isdst = dummy.tm_isdst;
+ date->tm_sec = sec;
+ date->tm_min = min;
+ date->tm_hour = hour;
+ date->tm_mday = mday;
+ date->tm_mon = mon - 1;
+ date->tm_year = base_year + year - 1900;
+ date->tm_gmtoff = 0;
+
+ ts = mktime(date);
+}
+
+static bool check_time(int wiggle)
+{
+ struct tm start, date[4], end;
+ struct tm *datep;
+ time_t ts;
+
+ /*
+ * This check assumes a few things. First, we cannot guarantee that we get
+ * a consistent reading from the wall clock because we may hit an edge of
+ * the clock while reading. To work around this, we read four clock
readings
+ * such that at least two of them should match. We need to assume that one
+ * reading is corrupt so we need four readings to ensure that we have at
+ * least two consecutive identical readings
+ *
+ * It's also possible that we'll cross an edge reading the host clock so
+ * simply check to make sure that the clock reading is within the period of
+ * when we expect it to be.
+ */
+
+ ts = time(NULL);
+ gmtime_r(&ts, &start);
+
+ cmos_get_date_time(&date[0]);
+ cmos_get_date_time(&date[1]);
+ cmos_get_date_time(&date[2]);
+ cmos_get_date_time(&date[3]);
+
+ ts = time(NULL);
+ gmtime_r(&ts, &end);
+
+ if (tm_cmp(&date[0], &date[1]) == 0) {
+ datep = &date[0];
+ } else if (tm_cmp(&date[1], &date[2]) == 0) {
+ datep = &date[1];
+ } else if (tm_cmp(&date[2], &date[3]) == 0) {
+ datep = &date[2];
+ } else {
+ g_assert_not_reached();
+ return false;
+ }
+
+ if (!(tm_cmp(&start, datep) <= 0 && tm_cmp(datep, &end) <= 0)) {
+ time_t t, s;
+
+ start.tm_isdst = datep->tm_isdst;
+
+ t = mktime(datep);
+ s = mktime(&start);
+ if (t < s) {
+ fprintf(stderr, "RTC is %ld second(s) behind wall-clock\n", (s -
t));
+ } else {
+ fprintf(stderr, "RTC is %ld second(s) ahead of wall-clock\n", (t -
s));
+ }
+
+ if (ABS(t - s) <= wiggle) {
+ return true;
+ }
+
+ return false;
+ }
+
+ return true;
+}
+
+int main(int argc, char **argv)
+{
+ // We update the RTC based on a timer that fires every second. But there's
+ // no guarantee that we'll get the timer at any point in time so when we
+ // read the CMOS time, the timer may be pending but not yet fired. That
+ // means we can be a few seconds behind.
+ //
+ // We really should do a gettimeofday() when CMOS time is read to get an
+ // accurate clock time but until then, give ourselves a little bit of
+ // wiggle room.
+ int wiggle = 2;
+
+ qtest_start(argv[1]);
+
+ // Set BCD mode
+ cmos_write(0x0B, cmos_read(0x0B) | 0x02);
+ if (!check_time(wiggle)) {
+ return 1;
+ }
+
+ // Set DEC mode
+ cmos_write(0x0B, cmos_read(0x0B) & ~0x02);
+ if (!check_time(wiggle)) {
+ return 1;
+ }
+
+ return 0;
+}
--
1.7.4.1
