From cbb5ba8633c2ad143366c3bc367f8c4f6434c084 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Sat, 1 Mar 2008 19:09:01 +0000 Subject: Rename lxbios to nvramtool, step 3 (rename directory). Signed-off-by: Uwe Hermann Acked-by: Stefan Reinauer git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3124 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- util/nvramtool/cmos_lowlevel.c | 299 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 299 insertions(+) create mode 100644 util/nvramtool/cmos_lowlevel.c (limited to 'util/nvramtool/cmos_lowlevel.c') diff --git a/util/nvramtool/cmos_lowlevel.c b/util/nvramtool/cmos_lowlevel.c new file mode 100644 index 0000000000..ab116797a2 --- /dev/null +++ b/util/nvramtool/cmos_lowlevel.c @@ -0,0 +1,299 @@ +/*****************************************************************************\ + * cmos_lowlevel.c + * $Id$ + ***************************************************************************** + * Copyright (C) 2002-2005 The Regents of the University of California. + * Produced at the Lawrence Livermore National Laboratory. + * Written by David S. Peterson . + * UCRL-CODE-2003-012 + * All rights reserved. + * + * This file is part of nvramtool, a utility for reading/writing coreboot + * parameters and displaying information from the coreboot table. + * For details, see http://coreboot.org/nvramtool. + * + * Please also read the file DISCLAIMER which is included in this software + * distribution. + * + * 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) version 2, dated June 1991. + * + * 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 terms and + * conditions of 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., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. +\*****************************************************************************/ + +#include +#include "common.h" +#include "cmos_lowlevel.h" + +typedef struct + { unsigned byte_index; + unsigned bit_offset; + } +cmos_bit_op_location_t; + +static unsigned cmos_bit_op_strategy (unsigned bit, unsigned bits_left, + cmos_bit_op_location_t *where); +static unsigned char cmos_read_bits (const cmos_bit_op_location_t *where, + unsigned nr_bits); +static void cmos_write_bits (const cmos_bit_op_location_t *where, + unsigned nr_bits, unsigned char value); +static unsigned char get_bits (unsigned long long value, unsigned bit, + unsigned nr_bits); +static void put_bits (unsigned char value, unsigned bit, unsigned nr_bits, + unsigned long long *result); + +/**************************************************************************** + * get_bits + * + * Extract a value 'nr_bits' bits wide starting at bit position 'bit' from + * 'value' and return the result. It is assumed that 'nr_bits' is at most 8. + ****************************************************************************/ +static inline unsigned char get_bits (unsigned long long value, unsigned bit, + unsigned nr_bits) + { return (value >> bit) & ((unsigned char) ((1 << nr_bits) - 1)); } + +/**************************************************************************** + * put_bits + * + * Extract the low order 'nr_bits' bits from 'value' and store them in the + * value pointed to by 'result' starting at bit position 'bit'. The bit + * positions in 'result' where the result is stored are assumed to be + * initially zero. + ****************************************************************************/ +static inline void put_bits (unsigned char value, unsigned bit, + unsigned nr_bits, unsigned long long *result) + { *result += (value & ((unsigned char) ((1 << nr_bits) - 1))) << bit; } + +/**************************************************************************** + * cmos_read + * + * Read value from nonvolatile RAM at position given by 'bit' and 'length' + * and return this value. The I/O privilege level of the currently executing + * process must be set appropriately. + ****************************************************************************/ +unsigned long long cmos_read (unsigned bit, unsigned length) + { cmos_bit_op_location_t where; + unsigned next_bit, bits_left, nr_bits; + unsigned long long result; + unsigned char value; + + assert(!verify_cmos_op(bit, length)); + result = 0; + + for (next_bit = 0, bits_left = length; + bits_left; + next_bit += nr_bits, bits_left -= nr_bits) + { nr_bits = cmos_bit_op_strategy(bit + next_bit, bits_left, &where); + value = cmos_read_bits(&where, nr_bits); + put_bits(value, next_bit, nr_bits, &result); + } + + return result; + } + +/**************************************************************************** + * cmos_write + * + * Write 'data' to nonvolatile RAM at position given by 'bit' and 'length'. + * The I/O privilege level of the currently executing process must be set + * appropriately. + ****************************************************************************/ +void cmos_write (unsigned bit, unsigned length, unsigned long long value) + { cmos_bit_op_location_t where; + unsigned next_bit, bits_left, nr_bits; + + assert(!verify_cmos_op(bit, length)); + + for (next_bit = 0, bits_left = length; + bits_left; + next_bit += nr_bits, bits_left -= nr_bits) + { nr_bits = cmos_bit_op_strategy(bit + next_bit, bits_left, &where); + cmos_write_bits(&where, nr_bits, get_bits(value, next_bit, nr_bits)); + } + } + +/**************************************************************************** + * cmos_read_byte + * + * Read a byte from nonvolatile RAM at a position given by 'index' and return + * the result. An 'index' value of 0 represents the first byte of + * nonvolatile RAM. + * + * Note: the first 14 bytes of nonvolatile RAM provide an interface to the + * real time clock. + ****************************************************************************/ +unsigned char cmos_read_byte (unsigned index) + { unsigned short port_0, port_1; + + assert(!verify_cmos_byte_index(index)); + + if (index < 128) + { port_0 = 0x70; + port_1 = 0x71; + } + else + { port_0 = 0x72; + port_1 = 0x73; + } + + outb(index, port_0); + return inb(port_1); + } + +/**************************************************************************** + * cmos_write_byte + * + * Write 'value' to nonvolatile RAM at a position given by 'index'. An + * 'index' of 0 represents the first byte of nonvolatile RAM. + * + * Note: the first 14 bytes of nonvolatile RAM provide an interface to the + * real time clock. Writing to any of these bytes will therefore + * affect its functioning. + ****************************************************************************/ +void cmos_write_byte (unsigned index, unsigned char value) + { unsigned short port_0, port_1; + + assert(!verify_cmos_byte_index(index)); + + if (index < 128) + { port_0 = 0x70; + port_1 = 0x71; + } + else + { port_0 = 0x72; + port_1 = 0x73; + } + + outb(index, port_0); + outb(value, port_1); + } + +/**************************************************************************** + * cmos_read_all + * + * Read all contents of CMOS memory into array 'data'. The first 14 bytes of + * 'data' are set to zero since this corresponds to the real time clock area. + ****************************************************************************/ +void cmos_read_all (unsigned char data[]) + { unsigned i; + + for (i = 0; i < CMOS_RTC_AREA_SIZE; i++) + data[i] = 0; + + for (; i < CMOS_SIZE; i++) + data[i] = cmos_read_byte(i); + } + +/**************************************************************************** + * cmos_write_all + * + * Update all of CMOS memory with the contents of array 'data'. The first 14 + * bytes of 'data' are ignored since this corresponds to the real time clock + * area. + ****************************************************************************/ +void cmos_write_all (unsigned char data[]) + { unsigned i; + + for (i = CMOS_RTC_AREA_SIZE; i < CMOS_SIZE; i++) + cmos_write_byte(i, data[i]); + } + +/**************************************************************************** + * set_iopl + * + * Set the I/O privilege level of the executing process. Root privileges are + * required for performing this action. A sufficient I/O privilege level + * allows the process to access x86 I/O address space and to disable/reenable + * interrupts while executing in user space. Messing with the I/O privilege + * level is therefore somewhat dangerous. + ****************************************************************************/ +void set_iopl (int level) + { assert((level >= 0) && (level <= 3)); + + if (iopl(level)) + { fprintf(stderr, + "%s: iopl() system call failed. You must be root to do " + "this.\n", + prog_name); + exit(1); + } + } + +/**************************************************************************** + * verify_cmos_op + * + * 'bit' represents a bit position in the nonvolatile RAM. The first bit + * (i.e. the lowest order bit of the first byte) of nonvolatile RAM is + * labeled as bit 0. 'length' represents the width in bits of a value we + * wish to read or write. Perform sanity checking on 'bit' and 'length'. If + * no problems were encountered, return OK. Else return an error code. + ****************************************************************************/ +int verify_cmos_op (unsigned bit, unsigned length) + { if ((bit >= (8 * CMOS_SIZE)) || ((bit + length) > (8 * CMOS_SIZE))) + return CMOS_AREA_OUT_OF_RANGE; + + if (bit < (8 * CMOS_RTC_AREA_SIZE)) + return CMOS_AREA_OVERLAPS_RTC; + + if (length > (8 * sizeof(unsigned long long))) + return CMOS_AREA_TOO_WIDE; + + return OK; + } + +/**************************************************************************** + * cmos_bit_op_strategy + * + * Helper function used by cmos_read() and cmos_write() to determine which + * bits to read or write next. + ****************************************************************************/ +static unsigned cmos_bit_op_strategy (unsigned bit, unsigned bits_left, + cmos_bit_op_location_t *where) + { unsigned max_bits; + + where->byte_index = bit >> 3; + where->bit_offset = bit & 0x07; + max_bits = 8 - where->bit_offset; + return (bits_left > max_bits) ? max_bits : bits_left; + } + +/**************************************************************************** + * cmos_read_bits + * + * Read a chunk of bits from a byte location within CMOS memory. Return the + * value represented by the chunk of bits. + ****************************************************************************/ +static unsigned char cmos_read_bits (const cmos_bit_op_location_t *where, + unsigned nr_bits) + { return (cmos_read_byte(where->byte_index) >> where->bit_offset) & + ((unsigned char) ((1 << nr_bits) - 1)); + } + +/**************************************************************************** + * cmos_write_bits + * + * Write a chunk of bits (the low order 'nr_bits' bits of 'value') to an area + * within a particular byte of CMOS memory. + ****************************************************************************/ +static void cmos_write_bits (const cmos_bit_op_location_t *where, + unsigned nr_bits, unsigned char value) + { unsigned char n, mask; + + if (nr_bits == 8) + { cmos_write_byte(where->byte_index, value); + return; + } + + n = cmos_read_byte(where->byte_index); + mask = ((unsigned char) ((1 << nr_bits) - 1)) << where->bit_offset; + n = (n & ~mask) + ((value << where->bit_offset) & mask); + cmos_write_byte(where->byte_index, n); + } -- cgit v1.2.3