[PATCH] nand: add nandflipbits tool
Boris Brezillon
boris.brezillon at free-electrons.com
Thu Nov 27 05:29:18 PST 2014
The nandflipbits tool is intended to be used when one need to flip one or
several specific bits on a NAND media.
It can be useful to manually recover from an unexpected bit flip on a flash
device, though the main purpose of this tool is to provide a way to test
ECC algorithms robustness.
One typical example I used this tool for is testing HW ECC engines behavior
when bitflips occur in an erased page: most HW engines do not correctly
handle this case, because, most of the time, ECC bits generated for an
empty page are not all 1s, and, empty page detection embedded in such
engines is only validating that all bits are set to 1s (which is not true
when a bit-flip has occurred).
Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
Makefile | 2 +-
nandflipbits.c | 332 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 333 insertions(+), 1 deletion(-)
create mode 100644 nandflipbits.c
diff --git a/Makefile b/Makefile
index eade234..55252f8 100644
--- a/Makefile
+++ b/Makefile
@@ -20,7 +20,7 @@ MTD_BINS = \
ftl_format flash_erase nanddump doc_loadbios \
ftl_check mkfs.jffs2 flash_lock flash_unlock \
flash_otp_info flash_otp_dump flash_otp_lock flash_otp_write \
- mtd_debug flashcp nandwrite nandtest \
+ mtd_debug flashcp nandwrite nandtest nandflipbits \
jffs2dump \
nftldump nftl_format docfdisk \
rfddump rfdformat \
diff --git a/nandflipbits.c b/nandflipbits.c
new file mode 100644
index 0000000..9ec39cf
--- /dev/null
+++ b/nandflipbits.c
@@ -0,0 +1,332 @@
+/*
+ * nandflipbits.c
+ *
+ * Copyright (C) 2014 Free Electrons
+ *
+ * Author: Boris Brezillon <boris.brezillon at free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Overview:
+ * This utility manually flip specified bits in a NAND flash.
+ *
+ */
+
+#define PROGRAM_NAME "nandwrite"
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <getopt.h>
+
+#include <asm/types.h>
+#include "mtd/mtd-user.h"
+#include "common.h"
+#include <libmtd.h>
+
+struct bit_flip {
+ int block;
+ off_t offset;
+ int bit;
+ bool done;
+};
+
+static void display_help(int status)
+{
+ fprintf(status == EXIT_SUCCESS ? stdout : stderr,
+"Usage: nandflipbits [OPTION] MTD_DEVICE <bit>@<address>[:<bit>@<address>]\n"
+"Writes to the specified MTD device.\n"
+"\n"
+" -o, --oob Provided addresses take OOB area into account\n"
+" -q, --quiet Don't display progress messages\n"
+" -h, --help Display this help and exit\n"
+" --version Output version information and exit\n"
+ );
+ exit(status);
+}
+
+static void display_version(void)
+{
+ printf("%1$s " VERSION "\n"
+ "\n"
+ "Copyright (C) 2014 Free Electrons \n"
+ "\n"
+ "%1$s comes with NO WARRANTY\n"
+ "to the extent permitted by law.\n"
+ "\n"
+ "You may redistribute copies of %1$s\n"
+ "under the terms of the GNU General Public Licence.\n"
+ "See the file `COPYING' for more information.\n",
+ PROGRAM_NAME);
+ exit(EXIT_SUCCESS);
+}
+
+static const char *mtd_device;
+static bool quiet = false;
+static bool oob_mode = false;
+static struct bit_flip *bits_to_flip;
+static int nbits_to_flip = 0;
+
+static void process_options(int argc, char * const argv[])
+{
+ char *bits_to_flip_iter;
+ int bit_idx = 0;
+ int error = 0;
+
+ for (;;) {
+ int option_index = 0;
+ static const char short_options[] = "hoq";
+ static const struct option long_options[] = {
+ /* Order of these args with val==0 matters; see option_index. */
+ {"version", no_argument, 0, 0},
+ {"help", no_argument, 0, 'h'},
+ {"oob", no_argument, 0, 'o'},
+ {"quiet", no_argument, 0, 'q'},
+ {0, 0, 0, 0},
+ };
+
+ int c = getopt_long(argc, argv, short_options,
+ long_options, &option_index);
+ if (c == EOF)
+ break;
+
+ switch (c) {
+ case 0:
+ if (!option_index) {
+ display_version();
+ break;
+ }
+ break;
+ case 'q':
+ quiet = true;
+ break;
+ case 'o':
+ oob_mode = true;
+ break;
+ case 'h':
+ display_help(EXIT_SUCCESS);
+ break;
+ case '?':
+ error++;
+ break;
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ /*
+ * There must be at least the MTD device node path argument remaining
+ * and the 'bits-to-flip' description.
+ */
+
+ if (argc != 2 || error)
+ display_help(EXIT_FAILURE);
+
+ mtd_device = argv[0];
+ bits_to_flip_iter = argv[1];
+ do {
+ nbits_to_flip++;
+ bits_to_flip_iter = strstr(bits_to_flip_iter, ":");
+ if (bits_to_flip_iter)
+ bits_to_flip_iter++;
+ } while (bits_to_flip_iter);
+
+ bits_to_flip = xmalloc(sizeof(*bits_to_flip) * nbits_to_flip);
+ bits_to_flip_iter = argv[1];
+
+ do {
+ struct bit_flip *bit_to_flip = &bits_to_flip[bit_idx++];
+
+ bit_to_flip->bit = strtol(bits_to_flip_iter,
+ &bits_to_flip_iter, 0);
+ if (errno || bit_to_flip->bit > 7)
+ goto err_invalid_bit_desc;
+
+ if (!bits_to_flip_iter || *bits_to_flip_iter++ != '@')
+ goto err_invalid_bit_desc;
+
+ bit_to_flip->offset = strtol(bits_to_flip_iter,
+ &bits_to_flip_iter, 0);
+
+ if (!bits_to_flip_iter || errno)
+ goto err_invalid_bit_desc;
+
+ bits_to_flip_iter = strstr(bits_to_flip_iter, ":");
+ if (bits_to_flip_iter)
+ bits_to_flip_iter++;
+ } while (bits_to_flip_iter);
+
+ return;
+
+err_invalid_bit_desc:
+ fprintf(stderr, "Invalid bit description\n");
+ exit(EXIT_FAILURE);
+}
+int main(int argc, char **argv)
+{
+ libmtd_t mtd_desc;
+ struct mtd_dev_info mtd;
+ int pagelen;
+ int pages_per_blk;
+ size_t blklen;
+ long long mtdlen;
+ int fd;
+ int ret;
+ uint8_t *buffer;
+ int i;
+
+ process_options(argc, argv);
+
+ /* Open the device */
+ if ((fd = open(mtd_device, O_RDWR)) == -1)
+ sys_errmsg_die("%s", mtd_device);
+
+ mtd_desc = libmtd_open();
+ if (!mtd_desc)
+ errmsg_die("can't initialize libmtd");
+
+ ret = ioctl(fd, MTDFILEMODE, MTD_FILE_MODE_RAW);
+ if (ret) {
+ printf("Failed to set MTD in raw access mode\n");
+ return -errno;
+ }
+
+ /* Fill in MTD device capability structure */
+ if (mtd_get_dev_info(mtd_desc, mtd_device, &mtd) < 0)
+ errmsg_die("mtd_get_dev_info failed");
+
+ /* Select OOB write mode */
+ ret = ioctl(fd, MTDFILEMODE, MTD_FILE_MODE_RAW);
+ if (ret) {
+ switch (errno) {
+ case ENOTTY:
+ errmsg_die("ioctl MTDFILEMODE is missing");
+ default:
+ sys_errmsg_die("MTDFILEMODE");
+ }
+ }
+
+ pagelen = mtd.min_io_size + (oob_mode ? mtd.oob_size : 0);
+ pages_per_blk = mtd.eb_size / mtd.min_io_size;
+ blklen = pages_per_blk * pagelen;
+ mtdlen = blklen * mtd.eb_cnt;
+ buffer = xmalloc((mtd.min_io_size + mtd.oob_size) * pages_per_blk);
+
+ for (i = 0; i < nbits_to_flip; i++) {
+ int page;
+
+ if (bits_to_flip[i].offset >= mtdlen)
+ errmsg_die("Invalid bit offset");
+
+ bits_to_flip[i].block = bits_to_flip[i].offset / blklen;
+ bits_to_flip[i].offset %= blklen;
+ page = bits_to_flip[i].offset / pagelen;
+ bits_to_flip[i].offset = (page *
+ (mtd.min_io_size + mtd.oob_size)) +
+ (bits_to_flip[i].offset % pagelen);
+
+ }
+
+ while (1) {
+ struct bit_flip *bit_to_flip = NULL;
+ int blkoffs;
+ int bufoffs;
+
+ for (i = 0; i < nbits_to_flip; i++) {
+ if (bits_to_flip[i].done == false) {
+ bit_to_flip = &bits_to_flip[i];
+ break;
+ }
+ }
+
+ if (!bit_to_flip)
+ break;
+
+ blkoffs = 0;
+ bufoffs = 0;
+ for (i = 0; i < pages_per_blk; i++) {
+ ret = mtd_read(&mtd, fd, bit_to_flip->block, blkoffs,
+ buffer + bufoffs, mtd.min_io_size);
+ if (ret) {
+ sys_errmsg("%s: MTD Read failure", mtd_device);
+ goto closeall;
+ }
+
+ bufoffs += mtd.min_io_size;
+
+ ret = mtd_read_oob(mtd_desc, &mtd, fd, blkoffs,
+ mtd.oob_size, buffer + bufoffs);
+ if (ret) {
+ sys_errmsg("%s: MTD Read OOB failure", mtd_device);
+ goto closeall;
+ }
+
+ bufoffs += mtd.oob_size;
+ blkoffs += mtd.min_io_size;
+ }
+
+ for (i = 0; i < nbits_to_flip; i++) {
+ unsigned char val, mask;
+
+ if (bits_to_flip[i].block != bit_to_flip->block)
+ continue;
+
+ mask = 1 << bits_to_flip[i].bit;
+ val = buffer[bits_to_flip[i].offset] & mask;
+ if (val)
+ buffer[bits_to_flip[i].offset] &= ~mask;
+ else
+ buffer[bits_to_flip[i].offset] |= mask;
+ }
+
+ ret = mtd_erase(mtd_desc, &mtd, fd, bit_to_flip->block);
+ if (ret) {
+ sys_errmsg("%s: MTD Erase failure", mtd_device);
+ goto closeall;
+ }
+
+ blkoffs = 0;
+ bufoffs = 0;
+ for (i = 0; i < pages_per_blk; i++) {
+ ret = mtd_write(mtd_desc, &mtd, fd, bit_to_flip->block,
+ blkoffs, buffer + bufoffs, mtd.min_io_size,
+ buffer + bufoffs + mtd.min_io_size,
+ mtd.oob_size,
+ MTD_OPS_RAW);
+ if (ret) {
+ sys_errmsg("%s: MTD Write failure", mtd_device);
+ goto closeall;
+ }
+
+ blkoffs += mtd.min_io_size;
+ bufoffs += mtd.min_io_size + mtd.oob_size;
+ }
+
+ for (i = 0; i < nbits_to_flip; i++) {
+ if (bits_to_flip[i].block == bit_to_flip->block)
+ bits_to_flip[i].done = true;
+ }
+ }
+
+ return 0;
+
+closeall:
+ libmtd_close(mtd_desc);
+ close(fd);
+ free(buffer);
+ exit(EXIT_FAILURE);
+}
--
1.9.1
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