openwrt/flashrom
1
0
Fork 0
mirror of https://review.coreboot.org/flashrom.git synced 2025-07-01 22:21:16 +02:00
Code Issues Releases Wiki Activity

writeprotect, cli_classic: delete old writeprotect code

Browse Source 
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 <nartemiev@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/58474
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
This commit is contained in:
Nikolai Artemiev
2021-10-20 22:11:32 +11:00
committed by Anastasia Klimchuk
parent 8d50fad443
commit 4571361d0e
5 changed files with 7 additions and 571 deletions
Download Patch File Download Diff File Expand all files Collapse all files

373
writeprotect.c
View File

@ -15,380 +15,11 @@
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#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,
};