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-rw-r--r--system/rtc.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/system/rtc.c b/system/rtc.c
new file mode 100644
index 0000000000..4904581abe
--- /dev/null
+++ b/system/rtc.c
@@ -0,0 +1,192 @@
+/*
+ * RTC configuration and clock read
+ *
+ * Copyright (c) 2003-2020 QEMU contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/timer.h"
+#include "qom/object.h"
+#include "sysemu/replay.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
+#include "hw/rtc/mc146818rtc.h"
+
+static enum {
+    RTC_BASE_UTC,
+    RTC_BASE_LOCALTIME,
+    RTC_BASE_DATETIME,
+} rtc_base_type = RTC_BASE_UTC;
+static time_t rtc_ref_start_datetime;
+static int rtc_realtime_clock_offset; /* used only with QEMU_CLOCK_REALTIME */
+static int rtc_host_datetime_offset = -1; /* valid & used only with
+                                             RTC_BASE_DATETIME */
+QEMUClockType rtc_clock;
+/***********************************************************/
+/* RTC reference time/date access */
+static time_t qemu_ref_timedate(QEMUClockType clock)
+{
+    time_t value = qemu_clock_get_ms(clock) / 1000;
+    switch (clock) {
+    case QEMU_CLOCK_REALTIME:
+        value -= rtc_realtime_clock_offset;
+        /* fall through */
+    case QEMU_CLOCK_VIRTUAL:
+        value += rtc_ref_start_datetime;
+        break;
+    case QEMU_CLOCK_HOST:
+        if (rtc_base_type == RTC_BASE_DATETIME) {
+            value -= rtc_host_datetime_offset;
+        }
+        break;
+    default:
+        assert(0);
+    }
+    return value;
+}
+
+void qemu_get_timedate(struct tm *tm, time_t offset)
+{
+    time_t ti = qemu_ref_timedate(rtc_clock);
+
+    ti += offset;
+
+    switch (rtc_base_type) {
+    case RTC_BASE_DATETIME:
+    case RTC_BASE_UTC:
+        gmtime_r(&ti, tm);
+        break;
+    case RTC_BASE_LOCALTIME:
+        localtime_r(&ti, tm);
+        break;
+    }
+}
+
+time_t qemu_timedate_diff(struct tm *tm)
+{
+    time_t seconds;
+
+    switch (rtc_base_type) {
+    case RTC_BASE_DATETIME:
+    case RTC_BASE_UTC:
+        seconds = mktimegm(tm);
+        break;
+    case RTC_BASE_LOCALTIME:
+    {
+        struct tm tmp = *tm;
+        tmp.tm_isdst = -1; /* use timezone to figure it out */
+        seconds = mktime(&tmp);
+        break;
+    }
+    default:
+        abort();
+    }
+
+    return seconds - qemu_ref_timedate(QEMU_CLOCK_HOST);
+}
+
+static void configure_rtc_base_datetime(const char *startdate)
+{
+    time_t rtc_start_datetime;
+    struct tm tm;
+
+    if (sscanf(startdate, "%d-%d-%dT%d:%d:%d", &tm.tm_year, &tm.tm_mon,
+               &tm.tm_mday, &tm.tm_hour, &tm.tm_min, &tm.tm_sec) == 6) {
+        /* OK */
+    } else if (sscanf(startdate, "%d-%d-%d",
+                      &tm.tm_year, &tm.tm_mon, &tm.tm_mday) == 3) {
+        tm.tm_hour = 0;
+        tm.tm_min = 0;
+        tm.tm_sec = 0;
+    } else {
+        goto date_fail;
+    }
+    tm.tm_year -= 1900;
+    tm.tm_mon--;
+    rtc_start_datetime = mktimegm(&tm);
+    if (rtc_start_datetime == -1) {
+    date_fail:
+        error_report("invalid datetime format");
+        error_printf("valid formats: "
+                     "'2006-06-17T16:01:21' or '2006-06-17'\n");
+        exit(1);
+    }
+    rtc_host_datetime_offset = rtc_ref_start_datetime - rtc_start_datetime;
+    rtc_ref_start_datetime = rtc_start_datetime;
+}
+
+void configure_rtc(QemuOpts *opts)
+{
+    const char *value;
+
+    /* Set defaults */
+    rtc_clock = QEMU_CLOCK_HOST;
+    rtc_ref_start_datetime = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
+    rtc_realtime_clock_offset = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
+
+    value = qemu_opt_get(opts, "base");
+    if (value) {
+        if (!strcmp(value, "utc")) {
+            rtc_base_type = RTC_BASE_UTC;
+        } else if (!strcmp(value, "localtime")) {
+            rtc_base_type = RTC_BASE_LOCALTIME;
+            replay_add_blocker("-rtc base=localtime");
+        } else {
+            rtc_base_type = RTC_BASE_DATETIME;
+            configure_rtc_base_datetime(value);
+        }
+    }
+    value = qemu_opt_get(opts, "clock");
+    if (value) {
+        if (!strcmp(value, "host")) {
+            rtc_clock = QEMU_CLOCK_HOST;
+        } else if (!strcmp(value, "rt")) {
+            rtc_clock = QEMU_CLOCK_REALTIME;
+        } else if (!strcmp(value, "vm")) {
+            rtc_clock = QEMU_CLOCK_VIRTUAL;
+        } else {
+            error_report("invalid option value '%s'", value);
+            exit(1);
+        }
+    }
+    value = qemu_opt_get(opts, "driftfix");
+    if (value) {
+        if (!strcmp(value, "slew")) {
+            object_register_sugar_prop(TYPE_MC146818_RTC,
+                                       "lost_tick_policy",
+                                       "slew",
+                                       false);
+            if (!object_class_by_name(TYPE_MC146818_RTC)) {
+                warn_report("driftfix 'slew' is not available with this machine");
+            }
+        } else if (!strcmp(value, "none")) {
+            /* discard is default */
+        } else {
+            error_report("invalid option value '%s'", value);
+            exit(1);
+        }
+    }
+}