cmd: nand biterr - Add support for nand biterr command

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/\
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>
This commit is contained in:
Balamanikandan Gunasundar 2021-06-29 12:46:11 +05:30 committed by Tom Rini
parent 75e33b378b
commit 4ea84c5dce

View file

@ -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>
@ -44,6 +48,116 @@ 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)
{
@ -733,8 +847,15 @@ static int do_nand(struct cmd_tbl *cmdtp, int flag, int argc,
}
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
@ -825,7 +946,7 @@ 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"