From b642e6d40a4347a5963e1f469ec863140b0cae59 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Mon, 31 Mar 2008 15:18:56 +0000 Subject: Rename drivers/cmos.c to drivers/nvram.c (trivial). Signed-off-by: Uwe Hermann Acked-by: Uwe Hermann git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3200 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- payloads/libpayload/drivers/nvram.c | 69 +++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 payloads/libpayload/drivers/nvram.c (limited to 'payloads/libpayload/drivers/nvram.c') diff --git a/payloads/libpayload/drivers/nvram.c b/payloads/libpayload/drivers/nvram.c new file mode 100644 index 0000000000..3789c09b3c --- /dev/null +++ b/payloads/libpayload/drivers/nvram.c @@ -0,0 +1,69 @@ +/* + * This file is part of the libpayload project. + * + * Copyright (C) 2008 Uwe Hermann + * + * 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 + +#define RTC_PORT 0x70 + +/** + * Read a byte from the specified NVRAM address. + * + * @param addr The NVRAM address to read a byte from. + * @return The byte at the given NVRAM address. + */ +u8 nvram_read(u8 addr) +{ + outb(addr, RTC_PORT); + return inb(RTC_PORT + 1); +} + +/** + * Write a byte to the specified NVRAM address. + * + * @param val The byte to write to NVRAM. + * @param addr The NVRAM address to write to. + */ +void nvram_write(u8 val, u8 addr) +{ + outb(addr, RTC_PORT); + outb(val, RTC_PORT + 1); +} -- cgit v1.2.3