Hello,
Can you please provide your comments on this patch.
Thanks, Balamanikandan
On 29/06/21 12:46 pm, Balamanikandan Gunasundar wrote:
The command shall be used to induce bit errors in the nand page manually. The code flips a bit in the specified offset without changing the ECC. This helps to see how the software handles the error.
The patch is ported from https://patchwork.ozlabs.org/project/uboot/patch/%5C 1325691123-19565-1-git-send-email-holger.brunck@keymile.com
The implementation is inspired from 'mtd-utils/nand-utils/nandflipbits.c'
Signed-off-by: Balamanikandan Gunasundar balamanikandan.gunasundar@microchip.com
cmd/nand.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 124 insertions(+), 3 deletions(-)
diff --git a/cmd/nand.c b/cmd/nand.c index 5bda69e819..ea1b0f9434 100644 --- a/cmd/nand.c +++ b/cmd/nand.c @@ -17,6 +17,10 @@
- and/or modified under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
- The function nand_biterror() in this file is inspired from
- mtd-utils/nand-utils/nandflipbits.c which was released under GPLv2
- only
*/
#include <common.h>
@@ -40,6 +44,116 @@ int find_dev_and_part(const char *id, struct mtd_device **dev, u8 *part_num, struct part_info **part); #endif
+#define MAX_NUM_PAGES 64
+static int nand_biterror(struct mtd_info *mtd, ulong off, int bit) +{
- int ret = 0;
- int page = 0;
- ulong block_off;
- u_char *datbuf[MAX_NUM_PAGES]; /* Data and OOB */
- u_char data;
- int pages_per_blk = mtd->erasesize / mtd->writesize;
- struct erase_info einfo;
- if (pages_per_blk > MAX_NUM_PAGES) {
printf("Too many pages in one erase block\n");return 1;- }
- if (bit < 0 || bit > 7) {
printf("bit position 0 to 7 is allowed\n");return 1;- }
- /* Allocate memory */
- memset(datbuf, 0, sizeof(datbuf));
- for (page = 0; page < pages_per_blk ; page++) {
datbuf[page] = malloc(mtd->writesize + mtd->oobsize);if (!datbuf[page]) {printf("No memory for page buffer\n");ret = -ENOMEM;goto free_memory;}- }
- /* Align to erase block boundary */
- block_off = off & (~(mtd->erasesize - 1));
- /* Read out memory as first step */
- for (page = 0; page < pages_per_blk ; page++) {
struct mtd_oob_ops ops;loff_t addr = (loff_t)block_off;memset(&ops, 0, sizeof(ops));ops.datbuf = datbuf[page];ops.oobbuf = datbuf[page] + mtd->writesize;ops.len = mtd->writesize;ops.ooblen = mtd->oobsize;ops.mode = MTD_OPS_RAW;ret = mtd_read_oob(mtd, addr, &ops);if (ret < 0) {printf("Error (%d) reading page %08lx\n",ret, block_off);ret = 1;goto free_memory;}block_off += mtd->writesize;- }
- /* Erase the block */
- memset(&einfo, 0, sizeof(einfo));
- einfo.mtd = mtd;
- /* Align to erase block boundary */
- einfo.addr = (loff_t)(off & (~(mtd->erasesize - 1)));
- einfo.len = mtd->erasesize;
- ret = mtd_erase(mtd, &einfo);
- if (ret < 0) {
printf("Error (%d) nand_erase_nand page %08llx\n",ret, einfo.addr);ret = 1;goto free_memory;- }
- /* Twist a bit in data part */
- block_off = off & (mtd->erasesize - 1);
- data = datbuf[block_off / mtd->writesize][block_off % mtd->writesize];
- data ^= (1 << bit);
- datbuf[block_off / mtd->writesize][block_off % mtd->writesize] = data;
- printf("Flip data at 0x%lx with xor 0x%02x (bit=%d) to value=0x%02x\n",
off, (1 << bit), bit, data);- /* Write back twisted data and unmodified OOB */
- /* Align to erase block boundary */
- block_off = off & (~(mtd->erasesize - 1));
- for (page = 0; page < pages_per_blk; page++) {
struct mtd_oob_ops ops;loff_t addr = (loff_t)block_off;memset(&ops, 0, sizeof(ops));ops.datbuf = datbuf[page];ops.oobbuf = datbuf[page] + mtd->writesize;ops.len = mtd->writesize;ops.ooblen = mtd->oobsize;ops.mode = MTD_OPS_RAW;ret = mtd_write_oob(mtd, addr, &ops);if (ret < 0) {printf("Error (%d) write page %08lx\n", ret, block_off);ret = 1;goto free_memory;}block_off += mtd->writesize;- }
+free_memory:
- for (page = 0; page < pages_per_blk ; page++) {
if (datbuf[page])free(datbuf[page]);- }
- return ret;
+}
- static int nand_dump(struct mtd_info *mtd, ulong off, int only_oob, int repeat) {
@@ -728,8 +842,15 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) }
if (strcmp(cmd, "biterr") == 0) {
/* todo */return 1;
int bit;if (argc != 4)goto usage;off = (int)simple_strtoul(argv[2], NULL, 16);bit = (int)simple_strtoul(argv[3], NULL, 10);ret = nand_biterror(mtd, off, bit);return ret;}
#ifdef CONFIG_CMD_NAND_LOCK_UNLOCK
@@ -820,7 +941,7 @@ static char nand_help_text[] = "nand scrub [-y] off size | scrub.part partition | scrub.chip\n" " really clean NAND erasing bad blocks (UNSAFE)\n" "nand markbad off [...] - mark bad block(s) at offset (UNSAFE)\n"
- "nand biterr off - make a bit error at offset (UNSAFE)"
- "nand biterr off bit - make a bit error at offset and bit position (UNSAFE)" #ifdef CONFIG_CMD_NAND_LOCK_UNLOCK "\n" "nand lock [tight] [status]\n"