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/*
* This file is part of the flashrom project.
*
* Copyright (C) 2010 Google Inc.
*
* 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
* (at your option) 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.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "flash.h"
#include "libflashrom.h"
#include "chipdrivers.h"
#include "writeprotect.h"
/** Read and extract a single bit from the chip's registers */
static enum flashrom_wp_result read_bit(uint8_t *value, bool *present, struct flashctx *flash, struct reg_bit_info bit)
{
*present = bit.reg != INVALID_REG;
if (*present) {
if (spi_read_register(flash, bit.reg, value))
return FLASHROM_WP_ERR_READ_FAILED;
*value = (*value >> bit.bit_index) & 1;
} else {
/* Zero bit, it may be used by compare_ranges(). */
*value = 0;
}
return FLASHROM_WP_OK;
}
/** Read all WP configuration bits from the chip's registers. */
static enum flashrom_wp_result read_wp_bits(struct wp_bits *bits, struct flashctx *flash)
{
/*
* For each WP bit that is included in the chip's register layout, read
* the register that contains it, extracts the bit's value, and assign
* it to the appropriate field in the wp_bits structure.
*/
const struct reg_bit_map *bit_map = &flash->chip->reg_bits;
bool ignored;
size_t i;
enum flashrom_wp_result ret;
ret = read_bit(&bits->tb, &bits->tb_bit_present, flash, bit_map->tb);
if (ret != FLASHROM_WP_OK)
return ret;
ret = read_bit(&bits->sec, &bits->sec_bit_present, flash, bit_map->sec);
if (ret != FLASHROM_WP_OK)
return ret;
ret = read_bit(&bits->cmp, &bits->cmp_bit_present, flash, bit_map->cmp);
if (ret != FLASHROM_WP_OK)
return ret;
ret = read_bit(&bits->srp, &bits->srp_bit_present, flash, bit_map->srp);
if (ret != FLASHROM_WP_OK)
return ret;
ret = read_bit(&bits->srl, &bits->srl_bit_present, flash, bit_map->srl);
if (ret != FLASHROM_WP_OK)
return ret;
for (i = 0; i < ARRAY_SIZE(bits->bp); i++) {
if (bit_map->bp[i].reg == INVALID_REG)
break;
bits->bp_bit_count = i + 1;
ret = read_bit(&bits->bp[i], &ignored, flash, bit_map->bp[i]);
if (ret != FLASHROM_WP_OK)
return ret;
}
return ret;
}
/** Helper function for write_wp_bits(). */
static void set_reg_bit(
uint8_t *reg_values, uint8_t *write_masks,
struct reg_bit_info bit, uint8_t value)
{
if (bit.reg != INVALID_REG) {
reg_values[bit.reg] |= value << bit.bit_index;
write_masks[bit.reg] |= 1 << bit.bit_index;
}
}
/** Write WP configuration bits to the flash's registers. */
static enum flashrom_wp_result write_wp_bits(struct flashctx *flash, struct wp_bits bits)
{
size_t i;
const struct reg_bit_map *reg_bits = &flash->chip->reg_bits;
/* Convert wp_bits to register values and write masks */
uint8_t reg_values[MAX_REGISTERS] = {0};
uint8_t write_masks[MAX_REGISTERS] = {0};
for (i = 0; i < bits.bp_bit_count; i++)
set_reg_bit(reg_values, write_masks, reg_bits->bp[i], bits.bp[i]);
set_reg_bit(reg_values, write_masks, reg_bits->tb, bits.tb);
set_reg_bit(reg_values, write_masks, reg_bits->sec, bits.sec);
set_reg_bit(reg_values, write_masks, reg_bits->cmp, bits.cmp);
set_reg_bit(reg_values, write_masks, reg_bits->srp, bits.srp);
set_reg_bit(reg_values, write_masks, reg_bits->srl, bits.srl);
/* Write each register */
for (enum flash_reg reg = STATUS1; reg < MAX_REGISTERS; reg++) {
if (!write_masks[reg])
continue;
uint8_t value;
if (spi_read_register(flash, reg, &value))
return FLASHROM_WP_ERR_READ_FAILED;
value = (value & ~write_masks[reg]) | (reg_values[reg] & write_masks[reg]);
if (spi_write_register(flash, reg, value))
return FLASHROM_WP_ERR_WRITE_FAILED;
}
/* Verify each register */
for (enum flash_reg reg = STATUS1; reg < MAX_REGISTERS; reg++) {
if (!write_masks[reg])
continue;
uint8_t value;
if (spi_read_register(flash, reg, &value))
return FLASHROM_WP_ERR_READ_FAILED;
uint8_t actual = value & write_masks[reg];
uint8_t expected = reg_values[reg] & write_masks[reg];
if (actual != expected)
return FLASHROM_WP_ERR_VERIFY_FAILED;
}
return FLASHROM_WP_OK;
}
static bool chip_supported(struct flashctx *flash)
{
return false;
}
enum flashrom_wp_result wp_read_cfg(struct flashrom_wp_cfg *cfg, struct flashctx *flash)
{
struct wp_bits bits;
enum flashrom_wp_result ret = FLASHROM_WP_OK;
if (!chip_supported(flash))
ret = FLASHROM_WP_ERR_CHIP_UNSUPPORTED;
if (ret == FLASHROM_WP_OK)
ret = read_wp_bits(&bits, flash);
/* TODO: implement get_wp_range() and get_wp_mode() and call them */
/*
if (ret == FLASHROM_WP_OK)
ret = get_wp_range(&cfg->range, flash, &bits);
if (ret == FLASHROM_WP_OK)
ret = get_wp_mode(&cfg->mode, &bits);
*/
return ret;
}
enum flashrom_wp_result wp_write_cfg(struct flashctx *flash, const struct flashrom_wp_cfg *cfg)
{
struct wp_bits bits;
enum flashrom_wp_result ret = FLASHROM_WP_OK;
if (!chip_supported(flash))
ret = FLASHROM_WP_ERR_CHIP_UNSUPPORTED;
if (ret == FLASHROM_WP_OK)
ret = read_wp_bits(&bits, flash);
/* Set protection range */
/* TODO: implement set_wp_range() and use it */
/*
if (ret == FLASHROM_WP_OK)
ret = set_wp_range(&bits, flash, cfg->range);
if (ret == FLASHROM_WP_OK)
ret = write_wp_bits(flash, bits);
*/
/* Set protection mode */
/* TODO: implement set_wp_mode() and use it */
/*
if (ret == FLASHROM_WP_OK)
ret = set_wp_mode(&bits, cfg->mode);
*/
if (ret == FLASHROM_WP_OK)
ret = write_wp_bits(flash, bits);
return ret;
}
/** @} */ /* end flashrom-wp */
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