--- /dev/null
+#ifndef _RTC_H
+#define _RTC_H
+
+/** @file
+ *
+ * CMOS Real-Time Clock (RTC)
+ *
+ * The CMOS/RTC registers are documented (with varying degrees of
+ * accuracy and consistency) at
+ *
+ * http://www.nondot.org/sabre/os/files/MiscHW/RealtimeClockFAQ.txt
+ * http://wiki.osdev.org/RTC
+ * http://wiki.osdev.org/CMOS
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <pic8259.h>
+
+/** RTC IRQ */
+#define RTC_IRQ 8
+
+/** RTC interrupt vector */
+#define RTC_INT IRQ_INT ( RTC_IRQ )
+
+/** CMOS/RTC address (and NMI) register */
+#define CMOS_ADDRESS 0x70
+
+/** NMI disable bit */
+#define CMOS_DISABLE_NMI 0x80
+
+/** CMOS/RTC data register */
+#define CMOS_DATA 0x71
+
+/** RTC seconds */
+#define RTC_SEC 0x00
+
+/** RTC minutes */
+#define RTC_MIN 0x02
+
+/** RTC hours */
+#define RTC_HOUR 0x04
+
+/** RTC weekday */
+#define RTC_WDAY 0x06
+
+/** RTC day of month */
+#define RTC_MDAY 0x07
+
+/** RTC month */
+#define RTC_MON 0x08
+
+/** RTC year */
+#define RTC_YEAR 0x09
+
+/** RTC status register A */
+#define RTC_STATUS_A 0x0a
+
+/** RTC update in progress bit */
+#define RTC_STATUS_A_UPDATE_IN_PROGRESS 0x80
+
+/** RTC status register B */
+#define RTC_STATUS_B 0x0b
+
+/** RTC 24 hour format bit */
+#define RTC_STATUS_B_24_HOUR 0x02
+
+/** RTC binary mode bit */
+#define RTC_STATUS_B_BINARY 0x04
+
+/** RTC Periodic Interrupt Enabled bit */
+#define RTC_STATUS_B_PIE 0x40
+
+/** RTC status register C */
+#define RTC_STATUS_C 0x0c
+
+/** RTC status register D */
+#define RTC_STATUS_D 0x0d
+
+/** CMOS default address */
+#define CMOS_DEFAULT_ADDRESS RTC_STATUS_D
+
+#endif /* _RTC_H */
*
* RTC-based entropy source
*
- * The CMOS/RTC registers are documented (with varying degrees of
- * accuracy and consistency) at
- *
- * http://www.nondot.org/sabre/os/files/MiscHW/RealtimeClockFAQ.txt
- * http://wiki.osdev.org/RTC
- * http://wiki.osdev.org/CMOS
*/
#include <stdint.h>
#include <string.h>
#include <biosint.h>
#include <pic8259.h>
+#include <rtc.h>
#include <ipxe/entropy.h>
-/** RTC IRQ */
-#define RTC_IRQ 8
-
-/** RTC interrupt vector */
-#define RTC_INT IRQ_INT ( RTC_IRQ )
-
-/** CMOS/RTC address (and NMI) register */
-#define CMOS_ADDRESS 0x70
-
-/** NMI disable bit */
-#define CMOS_DISABLE_NMI 0x80
-
-/** CMOS/RTC data register */
-#define CMOS_DATA 0x71
-
-/** RTC status register A */
-#define RTC_STATUS_A 0x0a
-
-/** RTC status register B */
-#define RTC_STATUS_B 0x0b
-
-/** RTC Periodic Interrupt Enabled bit */
-#define RTC_STATUS_B_PIE 0x40
-
-/** RTC status register C */
-#define RTC_STATUS_C 0x0c
-
-/** RTC status register D */
-#define RTC_STATUS_D 0x0d
-
-/** CMOS default address */
-#define CMOS_DEFAULT_ADDRESS RTC_STATUS_D
-
/** RTC "interrupt triggered" flag */
static uint8_t __text16 ( rtc_flag );
#define rtc_flag __use_text16 ( rtc_flag )
--- /dev/null
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * RTC-based time source
+ *
+ */
+
+#include <stdint.h>
+#include <time.h>
+#include <rtc.h>
+#include <ipxe/time.h>
+
+/**
+ * Read RTC register
+ *
+ * @v address Register address
+ * @ret data Data
+ */
+static unsigned int rtc_readb ( int address ) {
+ outb ( address, CMOS_ADDRESS );
+ return inb ( CMOS_DATA );
+}
+
+/**
+ * Check if RTC update is in progress
+ *
+ * @ret is_busy RTC update is in progress
+ */
+static int rtc_is_busy ( void ) {
+ return ( rtc_readb ( RTC_STATUS_A ) & RTC_STATUS_A_UPDATE_IN_PROGRESS );
+}
+
+/**
+ * Read RTC BCD register
+ *
+ * @v address Register address
+ * @ret value Value
+ */
+static unsigned int rtc_readb_bcd ( int address ) {
+ unsigned int bcd;
+
+ bcd = rtc_readb ( address );
+ return ( bcd - ( 6 * ( bcd >> 4 ) ) );
+}
+
+/**
+ * Read RTC time
+ *
+ * @ret time Time, in seconds
+ */
+static time_t rtc_read_time ( void ) {
+ unsigned int status_b;
+ int is_binary;
+ int is_24hour;
+ unsigned int ( * read_component ) ( int address );
+ struct tm tm;
+ int is_pm;
+ unsigned int hour;
+ time_t time;
+
+ /* Wait for any in-progress update to complete */
+ while ( rtc_is_busy() ) {}
+
+ /* Determine RTC mode */
+ status_b = rtc_readb ( RTC_STATUS_B );
+ is_binary = ( status_b & RTC_STATUS_B_BINARY );
+ is_24hour = ( status_b & RTC_STATUS_B_24_HOUR );
+ read_component = ( is_binary ? rtc_readb : rtc_readb_bcd );
+
+ /* Read time values */
+ tm.tm_sec = read_component ( RTC_SEC );
+ tm.tm_min = read_component ( RTC_MIN );
+ hour = read_component ( RTC_HOUR );
+ if ( ! is_24hour ) {
+ is_pm = ( hour >= 80 );
+ hour = ( ( ( ( hour & 0x7f ) % 80 ) % 12 ) +
+ ( is_pm ? 12 : 0 ) );
+ }
+ tm.tm_hour = hour;
+ tm.tm_mday = read_component ( RTC_MDAY );
+ tm.tm_mon = ( read_component ( RTC_MON ) - 1 );
+ tm.tm_year = ( read_component ( RTC_YEAR ) +
+ 100 /* Assume we are in the 21st century, since
+ * this code was written in 2012 */ );
+
+ DBGC ( RTC_STATUS_A, "RTCTIME is %04d-%02d-%02d %02d:%02d:%02d "
+ "(%s,%d-hour)\n", ( tm.tm_year + 1900 ), ( tm.tm_mon + 1 ),
+ tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
+ ( is_binary ? "binary" : "BCD" ), ( is_24hour ? 24 : 12 ) );
+
+ /* Convert to seconds since the Epoch */
+ time = mktime ( &tm );
+
+ return time;
+}
+
+/**
+ * Get current time in seconds
+ *
+ * @ret time Time, in seconds
+ */
+static time_t rtc_now ( void ) {
+ time_t time = 0;
+ time_t last_time;
+
+ /* Read time until we get two matching values in a row, in
+ * case we end up reading a corrupted value in the middle of
+ * an update.
+ */
+ do {
+ last_time = time;
+ time = rtc_read_time();
+ } while ( time != last_time );
+
+ return time;
+}
+
+PROVIDE_TIME ( rtc, time_now, rtc_now );
projects / thirdparty / ipxe.git / commitdiff
