70 lines
2.3 KiB
C
70 lines
2.3 KiB
C
|
/*
|
||
|
|
* This file is part of the libpayload project.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2008 Uwe Hermann <uwe@hermann-uwe.de>
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
* 3. The name of the author may not be used to endorse or promote products
|
||
|
|
* derived from this software without specific prior written permission.
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Datasheet:
|
||
|
|
* - Name: MC146818: Real-time Clock Plus RAM (RTC)
|
||
|
|
* - PDF: http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC146818.pdf
|
||
|
|
* - Order number: MC146818/D
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* See also:
|
||
|
|
* http://bochs.sourceforge.net/techspec/CMOS-reference.txt
|
||
|
|
* http://www.bioscentral.com/misc/cmosmap.htm
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <libpayload.h>
|
||
|
|
|
||
|
|
#define RTC_PORT 0x70
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Read a byte from the specified CMOS address.
|
||
|
|
*
|
||
|
|
* @param addr The CMOS address to read a byte from.
|
||
|
|
* @return The byte at the given CMOS address.
|
||
|
|
*/
|
||
|
|
u8 cmos_read(u8 addr)
|
||
|
|
{
|
||
|
|
outb(addr, RTC_PORT);
|
||
|
|
return inb(RTC_PORT + 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Write a byte to the specified CMOS address.
|
||
|
|
*
|
||
|
|
* @param val The byte to write to CMOS.
|
||
|
|
* @param addr The CMOS address to write to.
|
||
|
|
*/
|
||
|
|
void cmos_write(u8 val, u8 addr)
|
||
|
|
{
|
||
|
|
outb(addr, RTC_PORT);
|
||
|
|
outb(val, RTC_PORT + 1);
|
||
|
|
}
|