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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2014 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; version 2 of the License.
*
* 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 <stdint.h>
#include <stddef.h>
#include <bootmode.h>
#include <console/console.h>
#include <string.h>
#include <spi-generic.h>
#include <spi_flash.h>
#include <vendorcode/google/chromeos/chromeos.h>
#include "nvm.h"
/* Read flash status register to determine if write protect is active */
int nvm_is_write_protected(void)
{
u8 sr1;
u8 wp_gpio;
u8 wp_spi;
if (!IS_ENABLED(CONFIG_CHROMEOS))
return 0;
if (!IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH))
return 0;
/* Read Write Protect GPIO if available */
wp_gpio = get_write_protect_state();
/* Read Status Register 1 */
if (spi_flash_status(boot_device_spi_flash(), &sr1) < 0) {
printk(BIOS_ERR, "Failed to read SPI status register 1\n");
return -1;
}
wp_spi = !!(sr1 & 0x80);
printk(BIOS_DEBUG, "SPI flash protection: WPSW=%d SRP0=%d\n",
wp_gpio, wp_spi);
return wp_gpio && wp_spi;
}
/* Apply protection to a range of flash */
int nvm_protect(const struct region *r)
{
if (!IS_ENABLED(CONFIG_MRC_SETTINGS_PROTECT))
return 0;
if (!IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH))
return 0;
return spi_flash_ctrlr_protect_region(boot_device_spi_flash(), r);
}
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