From 4571361d0e2b11f43b2de5390c90705d4e8cce4a Mon Sep 17 00:00:00 2001 From: Nikolai Artemiev Date: Wed, 20 Oct 2021 22:11:32 +1100 Subject: writeprotect, cli_classic: delete old writeprotect code Delete writeprotect code that was previously extracted from the cros tree. This is the first of a series of commits adding writeprotect support. Following commits incrementally implement writeprotect operations, culminating in writeprotect support for three example chips: GD25LQ128, GD25Q32, and GD25Q256. BUG=b:195381327,b:153800563 BRANCH=none TEST=flashrom -{r,w,E} TEST=flashrom --wp-{enable,disable,range,list,status} at end of patch series Change-Id: I67e9b31f86465e5a8f7d3def637198671ee818a8 Signed-off-by: Nikolai Artemiev Reviewed-on: https://review.coreboot.org/c/flashrom/+/58474 Tested-by: build bot (Jenkins) Reviewed-by: Edward O'Callaghan Reviewed-by: Anastasia Klimchuk --- writeprotect.c | 373 +-------------------------------------------------------- 1 file changed, 2 insertions(+), 371 deletions(-) (limited to 'writeprotect.c') diff --git a/writeprotect.c b/writeprotect.c index b26c121c5..cfcb13c24 100644 --- a/writeprotect.c +++ b/writeprotect.c @@ -15,380 +15,11 @@ * */ +#include #include #include -#include #include "flash.h" -#include "flashchips.h" +#include "libflashrom.h" #include "chipdrivers.h" -#include "spi.h" #include "writeprotect.h" - -/* - * The following procedures rely on look-up tables to match the user-specified - * range with the chip's supported ranges. This turned out to be the most - * elegant approach since diferent flash chips use different levels of - * granularity and methods to determine protected ranges. In other words, - * be stupid and simple since clever arithmetic will not work for many chips. - */ - -struct wp_range { - unsigned int start; /* starting address */ - unsigned int len; /* len */ -}; - -enum bit_state { - OFF = 0, - ON = 1, - X = -1 /* don't care. Must be bigger than max # of bp. */ -}; - -/* - * Generic write-protection schema for 25-series SPI flash chips. This assumes - * there is a status register that contains one or more consecutive bits which - * determine which address range is protected. - */ - -struct status_register_layout { - int bp0_pos; /* position of BP0 */ - int bp_bits; /* number of block protect bits */ - int srp_pos; /* position of status register protect enable bit */ -}; - -/* - * The following ranges and functions are useful for representing the - * writeprotect schema in which there are typically 5 bits of - * relevant information stored in status register 1: - * m.sec: This bit indicates the units (sectors vs. blocks) - * m.tb: The top-bottom bit indicates if the affected range is at the top of - * the flash memory's address space or at the bottom. - * bp: Bitmask representing the number of affected sectors/blocks. - */ -struct wp_range_descriptor { - struct modifier_bits m; - unsigned int bp; /* block protect bitfield */ - struct wp_range range; -}; - -struct wp_context { - struct status_register_layout sr1; /* status register 1 */ - struct wp_range_descriptor *descrs; - - /* - * Some chips store modifier bits in one or more special control - * registers instead of the status register like many older SPI NOR - * flash chips did. get_modifier_bits() and set_modifier_bits() will do - * any chip-specific operations necessary to get/set these bit values. - */ - int (*get_modifier_bits)(const struct flashctx *flash, - struct modifier_bits *m); - int (*set_modifier_bits)(const struct flashctx *flash, - struct modifier_bits *m); -}; - -/* - * Mask to extract write-protect enable and range bits - * Status register 1: - * SRP0: bit 7 - * range(BP2-BP0): bit 4-2 - * range(BP3-BP0): bit 5-2 (large chips) - * Status register 2: - * SRP1: bit 1 - */ -#define MASK_WP_AREA (0x9C) -#define MASK_WP_AREA_LARGE (0x9C) -#define MASK_WP2_AREA (0x01) - -static uint8_t do_read_status(const struct flashctx *flash) -{ - if (flash->chip->read_status) - return flash->chip->read_status(flash); - else - return spi_read_status_register(flash); -} - -static int do_write_status(const struct flashctx *flash, int status) -{ - if (flash->chip->write_status) - return flash->chip->write_status(flash, status); - else - return spi_write_status_register(flash, status); -} - -enum wp_mode get_wp_mode(const char *mode_str) -{ - enum wp_mode wp_mode = WP_MODE_UNKNOWN; - - if (!strcasecmp(mode_str, "hardware")) - wp_mode = WP_MODE_HARDWARE; - else if (!strcasecmp(mode_str, "power_cycle")) - wp_mode = WP_MODE_POWER_CYCLE; - else if (!strcasecmp(mode_str, "permanent")) - wp_mode = WP_MODE_PERMANENT; - - return wp_mode; -} - -/* Given a flash chip, this function returns its writeprotect info. */ -static int generic_range_table(const struct flashctx *flash, - struct wp_context **wp, - int *num_entries) -{ - *wp = NULL; - *num_entries = 0; - - switch (flash->chip->manufacture_id) { - default: - msg_cerr("%s: flash vendor (0x%x) not found, aborting\n", - __func__, flash->chip->manufacture_id); - return -1; - } - - return 0; -} - -static uint8_t generic_get_bp_mask(struct wp_context *wp) -{ - return ((1 << (wp->sr1.bp0_pos + wp->sr1.bp_bits)) - 1) ^ \ - ((1 << wp->sr1.bp0_pos) - 1); -} - -static uint8_t generic_get_status_check_mask(struct wp_context *wp) -{ - return generic_get_bp_mask(wp) | 1 << wp->sr1.srp_pos; -} - -/* Given a [start, len], this function finds a block protect bit combination - * (if possible) and sets the corresponding bits in "status". Remaining bits - * are preserved. */ -static int generic_range_to_status(const struct flashctx *flash, - unsigned int start, unsigned int len, - uint8_t *status, uint8_t *check_mask) -{ - struct wp_context *wp; - struct wp_range_descriptor *r; - int i, range_found = 0, num_entries; - uint8_t bp_mask; - - if (generic_range_table(flash, &wp, &num_entries)) - return -1; - - bp_mask = generic_get_bp_mask(wp); - - for (i = 0, r = &wp->descrs[0]; i < num_entries; i++, r++) { - msg_cspew("comparing range 0x%x 0x%x / 0x%x 0x%x\n", - start, len, r->range.start, r->range.len); - if ((start == r->range.start) && (len == r->range.len)) { - *status &= ~(bp_mask); - *status |= r->bp << (wp->sr1.bp0_pos); - - if (wp->set_modifier_bits) { - if (wp->set_modifier_bits(flash, &r->m) < 0) { - msg_cerr("error setting modifier bits for range.\n"); - return -1; - } - } - - range_found = 1; - break; - } - } - - if (!range_found) { - msg_cerr("%s: matching range not found\n", __func__); - return -1; - } - - *check_mask = generic_get_status_check_mask(wp); - return 0; -} - -static int generic_status_to_range(const struct flashctx *flash, - const uint8_t sr1, unsigned int *start, unsigned int *len) -{ - struct wp_context *wp; - struct wp_range_descriptor *r; - int num_entries, i, status_found = 0; - uint8_t sr1_bp; - struct modifier_bits m; - - if (generic_range_table(flash, &wp, &num_entries)) - return -1; - - /* modifier bits may be compared more than once, so get them here */ - if (wp->get_modifier_bits && wp->get_modifier_bits(flash, &m) < 0) - return -1; - - sr1_bp = (sr1 >> wp->sr1.bp0_pos) & ((1 << wp->sr1.bp_bits) - 1); - - for (i = 0, r = &wp->descrs[0]; i < num_entries; i++, r++) { - if (wp->get_modifier_bits) { - if (memcmp(&m, &r->m, sizeof(m))) - continue; - } - msg_cspew("comparing 0x%02x 0x%02x\n", sr1_bp, r->bp); - if (sr1_bp == r->bp) { - *start = r->range.start; - *len = r->range.len; - status_found = 1; - break; - } - } - - if (!status_found) { - msg_cerr("matching status not found\n"); - return -1; - } - - return 0; -} - -/* Given a [start, len], this function calls generic_range_to_status() to - * convert it to flash-chip-specific range bits, then sets into status register. - */ -static int generic_set_range(const struct flashctx *flash, - unsigned int start, unsigned int len) -{ - uint8_t status, expected, check_mask; - - status = do_read_status(flash); - msg_cdbg("%s: old status: 0x%02x\n", __func__, status); - - expected = status; /* preserve non-bp bits */ - if (generic_range_to_status(flash, start, len, &expected, &check_mask)) - return -1; - - do_write_status(flash, expected); - - status = do_read_status(flash); - msg_cdbg("%s: new status: 0x%02x\n", __func__, status); - if ((status & check_mask) != (expected & check_mask)) { - msg_cerr("expected=0x%02x, but actual=0x%02x. check mask=0x%02x\n", - expected, status, check_mask); - return 1; - } - return 0; -} - -/* Set/clear the status regsiter write protect bit in SR1. */ -static int generic_set_srp0(const struct flashctx *flash, int enable) -{ - uint8_t status, expected, check_mask; - struct wp_context *wp; - int num_entries; - - if (generic_range_table(flash, &wp, &num_entries)) - return -1; - - expected = do_read_status(flash); - msg_cdbg("%s: old status: 0x%02x\n", __func__, expected); - - if (enable) - expected |= 1 << wp->sr1.srp_pos; - else - expected &= ~(1 << wp->sr1.srp_pos); - - do_write_status(flash, expected); - - status = do_read_status(flash); - msg_cdbg("%s: new status: 0x%02x\n", __func__, status); - - check_mask = generic_get_status_check_mask(wp); - msg_cdbg("%s: check mask: 0x%02x\n", __func__, check_mask); - if ((status & check_mask) != (expected & check_mask)) { - msg_cerr("expected=0x%02x, but actual=0x%02x. check mask=0x%02x\n", - expected, status, check_mask); - return -1; - } - - return 0; -} - -static int generic_enable_writeprotect(const struct flashctx *flash, - enum wp_mode wp_mode) -{ - int ret; - - if (wp_mode != WP_MODE_HARDWARE) { - msg_cerr("%s(): unsupported write-protect mode\n", __func__); - return 1; - } - - ret = generic_set_srp0(flash, 1); - if (ret) - msg_cerr("%s(): error=%d.\n", __func__, ret); - - return ret; -} - -static int generic_disable_writeprotect(const struct flashctx *flash) -{ - int ret; - - ret = generic_set_srp0(flash, 0); - if (ret) - msg_cerr("%s(): error=%d.\n", __func__, ret); - - return ret; -} - -static int generic_list_ranges(const struct flashctx *flash) -{ - struct wp_context *wp; - struct wp_range_descriptor *r; - int i, num_entries; - - if (generic_range_table(flash, &wp, &num_entries)) - return -1; - - r = &wp->descrs[0]; - for (i = 0; i < num_entries; i++) { - msg_cinfo("start: 0x%06x, length: 0x%06x\n", - r->range.start, r->range.len); - r++; - } - - return 0; -} - -static int wp_context_status(const struct flashctx *flash) -{ - uint8_t sr1; - unsigned int start, len; - int ret = 0; - struct wp_context *wp; - int num_entries, wp_en; - - if (generic_range_table(flash, &wp, &num_entries)) - return -1; - - sr1 = do_read_status(flash); - wp_en = (sr1 >> wp->sr1.srp_pos) & 1; - - msg_cinfo("WP: status: 0x%04x\n", sr1); - msg_cinfo("WP: status.srp0: %x\n", wp_en); - /* FIXME: SRP1 is not really generic, but we probably should print - * it anyway to have consistent output. #legacycruft */ - msg_cinfo("WP: status.srp1: %x\n", 0); - msg_cinfo("WP: write protect is %s.\n", - wp_en ? "enabled" : "disabled"); - - msg_cinfo("WP: write protect range: "); - if (generic_status_to_range(flash, sr1, &start, &len)) { - msg_cinfo("(cannot resolve the range)\n"); - ret = -1; - } else { - msg_cinfo("start=0x%08x, len=0x%08x\n", start, len); - } - - return ret; -} - -struct wp wp_generic = { - .list_ranges = generic_list_ranges, - .set_range = generic_set_range, - .enable = generic_enable_writeprotect, - .disable = generic_disable_writeprotect, - .wp_status = wp_context_status, -}; -- cgit v1.2.3