diff options
| -rw-r--r-- | libflashrom.c | 125 | ||||
| -rw-r--r-- | libflashrom.h | 29 | ||||
| -rw-r--r-- | writeprotect.c | 188 | ||||
| -rw-r--r-- | writeprotect.h | 21 |
4 files changed, 363 insertions, 0 deletions
diff --git a/libflashrom.c b/libflashrom.c index 5f14c681..f0b9cfda 100644 --- a/libflashrom.c +++ b/libflashrom.c @@ -31,6 +31,7 @@ #include "layout.h" #include "ich_descriptors.h" #include "libflashrom.h" +#include "writeprotect.h" /** * @defgroup flashrom-general General @@ -623,3 +624,127 @@ void flashrom_layout_set(struct flashrom_flashctx *const flashctx, const struct } /** @} */ /* end flashrom-layout */ + + +/** + * @defgroup flashrom-wp + * @{ + */ + +/** + * @brief Create a new empty WP configuration. + * + * @param[out] cfg Points to a pointer of type struct flashrom_wp_cfg that will + * be set if creation succeeds. *cfg has to be freed by the + * caller with @ref flashrom_wp_cfg_release. + * @return 0 on success + * >0 on failure + */ +enum flashrom_wp_result flashrom_wp_cfg_new(struct flashrom_wp_cfg **cfg) +{ + *cfg = calloc(1, sizeof(**cfg)); + return *cfg ? 0 : FLASHROM_WP_ERR_OTHER; +} + +/** + * @brief Free a WP configuration. + * + * @param[out] cfg Pointer to the flashrom_wp_cfg to free. + */ +void flashrom_wp_cfg_release(struct flashrom_wp_cfg *cfg) +{ + free(cfg); +} + +/** + * @brief Set the protection mode for a WP configuration. + * + * @param[in] mode The protection mode to set. + * @param[out] cfg Pointer to the flashrom_wp_cfg structure to modify. + */ +void flashrom_wp_set_mode(struct flashrom_wp_cfg *cfg, enum flashrom_wp_mode mode) +{ + cfg->mode = mode; +} + +/** + * @brief Get the protection mode from a WP configuration. + * + * @param[in] cfg The WP configuration to get the protection mode from. + * @return The configuration's protection mode. + */ +enum flashrom_wp_mode flashrom_wp_get_mode(const struct flashrom_wp_cfg *cfg) +{ + return cfg->mode; +} + +/** + * @brief Set the protection range for a WP configuration. + * + * @param[out] cfg Pointer to the flashrom_wp_cfg structure to modify. + * @param[in] start The range's start address. + * @param[in] len The range's length. + */ +void flashrom_wp_set_range(struct flashrom_wp_cfg *cfg, size_t start, size_t len) +{ + cfg->range.start = start; + cfg->range.len = len; +} + +/** + * @brief Get the protection range from a WP configuration. + * + * @param[out] start Points to a size_t to write the range start to. + * @param[out] len Points to a size_t to write the range length to. + * @param[in] cfg The WP configuration to get the range from. + */ +void flashrom_wp_get_range(size_t *start, size_t *len, const struct flashrom_wp_cfg *cfg) +{ + *start = cfg->range.start; + *len = cfg->range.len; +} + +/** + * @brief Write a WP configuration to a flash chip. + * + * @param[in] flash The flash context used to access the chip. + * @param[in] cfg The WP configuration to write to the chip. + * @return 0 on success + * >0 on failure + */ +enum flashrom_wp_result flashrom_wp_write_cfg(struct flashctx *flash, const struct flashrom_wp_cfg *cfg) +{ + /* + * TODO: Call custom implementation if the programmer is opaque, as + * direct WP operations require SPI access. In particular, linux_mtd + * has its own WP operations we should use instead. + */ + if (flash->mst->buses_supported & BUS_SPI) + return wp_write_cfg(flash, cfg); + + return FLASHROM_WP_ERR_OTHER; +} + +/** + * @brief Read the current WP configuration from a flash chip. + * + * @param[out] cfg Pointer to a struct flashrom_wp_cfg to store the chip's + * configuration in. + * @param[in] flash The flash context used to access the chip. + * @return 0 on success + * >0 on failure + */ +enum flashrom_wp_result flashrom_wp_read_cfg(struct flashrom_wp_cfg *cfg, struct flashctx *flash) +{ + /* + * TODO: Call custom implementation if the programmer is opaque, as + * direct WP operations require SPI access. In particular, linux_mtd + * has its own WP operations we should use instead. + */ + if (flash->mst->buses_supported & BUS_SPI) + return wp_read_cfg(cfg, flash); + + return FLASHROM_WP_ERR_OTHER; +} + +/** @} */ /* end flashrom-wp */ diff --git a/libflashrom.h b/libflashrom.h index 1c9498ec..6d02d50f 100644 --- a/libflashrom.h +++ b/libflashrom.h @@ -1,6 +1,7 @@ /* * This file is part of the flashrom project. * + * Copyright (C) 2010 Google Inc. * Copyright (C) 2012 secunet Security Networks AG * (Written by Nico Huber <nico.huber@secunet.com> for secunet) * @@ -119,4 +120,32 @@ int flashrom_layout_get_region_range(struct flashrom_layout *, const char *name, void flashrom_layout_release(struct flashrom_layout *); void flashrom_layout_set(struct flashrom_flashctx *, const struct flashrom_layout *); +/** @ingroup flashrom-wp */ +enum flashrom_wp_result { + FLASHROM_WP_OK = 0, + FLASHROM_WP_ERR_CHIP_UNSUPPORTED = 1, + FLASHROM_WP_ERR_OTHER = 2, + FLASHROM_WP_ERR_READ_FAILED = 3, + FLASHROM_WP_ERR_WRITE_FAILED = 4, + FLASHROM_WP_ERR_VERIFY_FAILED = 5 +}; + +enum flashrom_wp_mode { + FLASHROM_WP_MODE_DISABLED, + FLASHROM_WP_MODE_HARDWARE, + FLASHROM_WP_MODE_POWER_CYCLE, + FLASHROM_WP_MODE_PERMANENT +}; +struct flashrom_wp_cfg; + +enum flashrom_wp_result flashrom_wp_cfg_new(struct flashrom_wp_cfg **); +void flashrom_wp_cfg_release(struct flashrom_wp_cfg *); +void flashrom_wp_set_mode(struct flashrom_wp_cfg *, enum flashrom_wp_mode); +enum flashrom_wp_mode flashrom_wp_get_mode(const struct flashrom_wp_cfg *); +void flashrom_wp_set_range(struct flashrom_wp_cfg *, size_t start, size_t len); +void flashrom_wp_get_range(size_t *start, size_t *len, const struct flashrom_wp_cfg *); + +enum flashrom_wp_result flashrom_wp_read_cfg(struct flashrom_wp_cfg *, struct flashrom_flashctx *); +enum flashrom_wp_result flashrom_wp_write_cfg(struct flashrom_flashctx *, const struct flashrom_wp_cfg *); + #endif /* !__LIBFLASHROM_H__ */ diff --git a/writeprotect.c b/writeprotect.c index cfcb13c2..20b5afcc 100644 --- a/writeprotect.c +++ b/writeprotect.c @@ -23,3 +23,191 @@ #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 */ diff --git a/writeprotect.h b/writeprotect.h index 2f473f74..d54befad 100644 --- a/writeprotect.h +++ b/writeprotect.h @@ -22,8 +22,21 @@ #include <stdbool.h> #include <stddef.h> +#include "libflashrom.h" + #define MAX_BP_BITS 4 +/* Chip protection range: start address and length. */ +struct wp_range { + size_t start, len; +}; + +/* Generic description of a chip's write protection configuration. */ +struct flashrom_wp_cfg { + enum flashrom_wp_mode mode; + struct wp_range range; +}; + /* * Description of a chip's write protection configuration. * @@ -56,4 +69,12 @@ struct wp_bits { uint8_t bp[MAX_BP_BITS]; }; +struct flashrom_flashctx; + +/* Write WP configuration to the chip */ +enum flashrom_wp_result wp_write_cfg(struct flashrom_flashctx *, const struct flashrom_wp_cfg *); + +/* Read WP configuration from the chip */ +enum flashrom_wp_result wp_read_cfg(struct flashrom_wp_cfg *, struct flashrom_flashctx *); + #endif /* !__WRITEPROTECT_H__ */ |