summaryrefslogtreecommitdiffstats
path: root/stand/pc98/libpc98/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'stand/pc98/libpc98/time.c')
-rw-r--r--stand/pc98/libpc98/time.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/stand/pc98/libpc98/time.c b/stand/pc98/libpc98/time.c
new file mode 100644
index 0000000..5d832bb
--- /dev/null
+++ b/stand/pc98/libpc98/time.c
@@ -0,0 +1,98 @@
+/*-
+ * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stand.h>
+#include <btxv86.h>
+#include <machine/cpufunc.h>
+#include "bootstrap.h"
+#include "libi386.h"
+
+static int bios_seconds(void);
+
+/*
+ * Return the BIOS time-of-day value.
+ *
+ * XXX uses undocumented BCD support from libstand.
+ */
+static int
+bios_seconds(void)
+{
+ int hr, minute, sec;
+ unsigned char bios_time[6];
+
+ v86.ctl = 0;
+ v86.addr = 0x1c; /* int 0x1c, function 0 */
+ v86.eax = 0x0000;
+ v86.es = VTOPSEG(bios_time);
+ v86.ebx = VTOPOFF(bios_time);
+ v86int();
+
+ hr = bcd2bin(bios_time[3]);
+ minute = bcd2bin(bios_time[4]);
+ sec = bcd2bin(bios_time[5]);
+
+ return (hr * 3600 + minute * 60 + sec);
+}
+
+/*
+ * Return the time in seconds since the beginning of the day.
+ */
+time_t
+time(time_t *t)
+{
+ static time_t lasttime;
+ time_t now;
+
+ now = bios_seconds();
+
+ if (now < lasttime)
+ now += 24 * 3600;
+ lasttime = now;
+
+ if (t != NULL)
+ *t = now;
+ return(now);
+}
+
+/*
+ * Use the BIOS Wait function to pause for (period) microseconds.
+ *
+ * Resolution of this function is variable, but typically around
+ * 1ms.
+ */
+void
+delay(int period)
+{
+ int i;
+
+ period = (period + 500) / 1000;
+ for( ; period != 0 ; period--)
+ for(i=800;i != 0; i--)
+ outb(0x5f,0); /* wait 600ns */
+}
OpenPOWER on IntegriCloud