[U-Boot] [PATCH 2/2] i.MX6: nand: add nandbcb command for imx

Stefano Babic sbabic at denx.de
Mon Jun 10 16:47:54 UTC 2019


Hi Jagan, Shyam,

On 06/06/19 10:59, Shyam Saini wrote:
> Writing/updating boot image in nand device is not
> straight forward in i.MX6 platform and it requires
> boot control block(BCB) to be configured.
> 
> It becomes difficult to use uboot 'nand' command to
> write BCB since it requires platform specific attributes
> need to be taken care of.
> 
> It is even difficult to use existing msx-nand.c driver by
> incorporating BCB attributes like mxs_dma_desc does
> because it requires change in mtd and nand command.
> 
> So, cmd_nandbcb implemented in arch/arm/mach-imx
> 
> BCB contains two data structures, Firmware Configuration Block(FCB)
> and Discovered Bad Block Table(DBBT). FCB has nand timings,
> DBBT search area, page address of firmware.
> 
> On summary, nandbcb update will
> - erase the entire partition
> - create BCB by creating 2 FCB/DBBT block followed by
>   1 FW block based on partition size and erasesize.
> - fill FCB/DBBT structures
> - write FW/SPL on FW1
> - write FCB/DBBT in first 2 blocks
> 
> for nand boot, up on reset bootrom look for FCB structure in
> first block's if FCB found the nand timings are loaded for
> further reads. once FCB read done, DTTB will load and finally
> firmware will be loaded which is boot image.
> 
> Refer section "NAND Boot" from doc/imx/common/imx6.txt for more usage
> information.


Thanks for this work - this is still missing in current U-Boot. I will
merge this for the upcoming release - letting this in, we could win some
more testers helping to adjust if there are some issues.

Thanks again,
Stefano

> 
> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> Signed-off-by: Sergey Kubushyn <ksi at koi8.net>
> Signed-off-by: Shyam Saini <shyam.saini at amarulasolutions.com>
> ---
> Changes for v4:
> - Remove obselete apis and use bch_geometry structure for calculating
>   ecc level, bad block start bit and bad block byte
> - Write firmware only once
> - Shorten variable names
> - Update commit message
> - Update docs as per current patch
> - Fix checkpatch warnings
> Changes for v3:
> - Fixed multi-line comments
> - Better error handling for failed allocations
> Changes for v2:
> - Fixed commit message notes
> - Updated proper commit message
> - Update doc/README.imx6 with NAND boot details
> - Fixed long length variable names.
> - Fixed Gigantic variable name.
> - NULL checks for kzalloc
> - Move Kconfig option in separate patch
> - Fixed checkpatch warninigs
> ---
>  arch/arm/include/asm/mach-imx/imx-nandbcb.h        | 111 +++++++
>  .../arm/include/asm/mach-imx/mxs-nand.h            |   0
>  arch/arm/mach-imx/Makefile                         |   1 +
>  arch/arm/mach-imx/cmd_nandbcb.c                    | 369 +++++++++++++++++++++
>  doc/imx/common/imx6.txt                            |  75 +++++
>  drivers/mtd/nand/raw/mxs_nand.c                    |   2 +-
>  drivers/mtd/nand/raw/mxs_nand_spl.c                |   3 +-
>  7 files changed, 559 insertions(+), 2 deletions(-)
>  create mode 100644 arch/arm/include/asm/mach-imx/imx-nandbcb.h
>  rename drivers/mtd/nand/raw/mxs_nand.h => arch/arm/include/asm/mach-imx/mxs-nand.h (100%)
>  create mode 100644 arch/arm/mach-imx/cmd_nandbcb.c
> 
> diff --git a/arch/arm/include/asm/mach-imx/imx-nandbcb.h b/arch/arm/include/asm/mach-imx/imx-nandbcb.h
> new file mode 100644
> index 0000000000..033659a038
> --- /dev/null
> +++ b/arch/arm/include/asm/mach-imx/imx-nandbcb.h
> @@ -0,0 +1,111 @@
> +/*
> + * Copyright (C) 2017 Jagan Teki <jagan at amarulasolutions.com>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#ifndef _IMX_NAND_BCB_H_
> +#define _IMX_NAND_BCB_H_
> +
> +#define FCB_FINGERPRINT		0x20424346      /* 'FCB' */
> +#define FCB_VERSION_1		0x01000000
> +
> +#define DBBT_FINGERPRINT2	0x54424244	/* 'DBBT' */
> +#define DBBT_VERSION_1		0x01000000
> +
> +struct dbbt_block {
> +	u32 checksum;	/* reserved on i.MX6 */
> +	u32 fingerprint;
> +	u32 version;
> +	u32 numberbb;	/* reserved on i.MX6 */
> +	u32 dbbtpages;
> +};
> +
> +struct fcb_block {
> +	u32 checksum;		/* First fingerprint in first byte */
> +	u32 fingerprint;	/* 2nd fingerprint at byte 4 */
> +	u32 version;		/* 3rd fingerprint at byte 8 */
> +	u8 datasetup;
> +	u8 datahold;
> +	u8 addr_setup;
> +	u8 dsample_time;
> +
> +	/* These are for application use only and not for ROM. */
> +	u8 nandtiming;
> +	u8 rea;
> +	u8 rloh;
> +	u8 rhoh;
> +	u32 pagesize;		/* 2048 for 2K pages, 4096 for 4K pages */
> +	u32 oob_pagesize;	/* 2112 for 2K pages, 4314 for 4K pages */
> +	u32 sectors;		/* Number of 2K sections per block */
> +	u32 nr_nand;		/* Total Number of NANDs - not used by ROM */
> +	u32 nr_die;		/* Number of separate chips in this NAND */
> +	u32 celltype;		/* MLC or SLC */
> +	u32 ecc_type;		/* Type of ECC, can be one of BCH-0-20 */
> +	u32 ecc_nr;		/* Number of bytes for Block0 - BCH */
> +
> +	/* Block size in bytes for all blocks other than Block0 - BCH */
> +	u32 ecc_size;
> +	u32 ecc_level;		/* Ecc level for Block 0 - BCH */
> +	u32 meta_size;		/* Metadata size - BCH */
> +	/* Number of blocks per page for ROM use - BCH */
> +	u32 nr_blocks;
> +	u32 ecc_type_sdk;	/* Type of ECC, can be one of BCH-0-20 */
> +	u32 ecc_nr_sdk;		/* Number of bytes for Block0 - BCH */
> +	/* Block size in bytes for all blocks other than Block0 - BCH */
> +	u32 ecc_size_sdk;
> +	u32 ecc_level_sdk;	/* Ecc level for Block 0 - BCH */
> +	/* Number of blocks per page for SDK use - BCH */
> +	u32 nr_blocks_sdk;
> +	u32 meta_size_sdk;	/* Metadata size - BCH */
> +	u32 erase_th;		/* To set into BCH_MODE register */
> +
> +	/*
> +	 * 0: normal boot
> +	 * 1: to load patch starting next to FCB
> +	 */
> +	u32 bootpatch;
> +	u32 patch_size;	/* Size of patch in sectors */
> +	u32 fw1_start;	/* Firmware image starts on this sector */
> +	u32 fw2_start;	/* Secondary FW Image starting Sector */
> +	u32 fw1_pages;	/* Number of sectors in firmware image */
> +	u32 fw2_pages;	/* Number of sector in secondary FW image */
> +	u32 dbbt_start; /* Page address where dbbt search area begins */
> +
> +	/*
> +	 * Byte in page data that have manufacturer marked bad block marker,
> +	 * this will be swapped with metadata[0] to complete page data.
> +	 */
> +	u32 bb_byte;
> +
> +	/*
> +	 * For BCH ECC sizes other than 8 and 16 the bad block marker does not
> +	 * start at 0th bit of bb_byte. This field is used to get to
> +	 * the start bit of bad block marker byte with in bb_byte
> +	 */
> +	u32 bb_start_bit;
> +
> +	/*
> +	 * FCB value that gives byte offset for
> +	 * bad block marker on physical NAND page
> +	 */
> +	u32 phy_offset;
> +	u32 bchtype;
> +
> +	u32 readlatency;
> +	u32 predelay;
> +	u32 cedelay;
> +	u32 postdelay;
> +	u32 cmdaddpause;
> +	u32 datapause;
> +	u32 tmspeed;
> +	u32 busytimeout;
> +
> +	/* the flag to enable (1)/disable(0) bi swap */
> +	u32 disbbm;
> +
> +	/* The swap position of main area in spare area */
> +	u32 spare_offset;
> +};
> +
> +#endif	/* _IMX_NAND_BCB_H_ */
> diff --git a/drivers/mtd/nand/raw/mxs_nand.h b/arch/arm/include/asm/mach-imx/mxs-nand.h
> similarity index 100%
> rename from drivers/mtd/nand/raw/mxs_nand.h
> rename to arch/arm/include/asm/mach-imx/mxs-nand.h
> diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> index 37675d0558..e740d0c1e8 100644
> --- a/arch/arm/mach-imx/Makefile
> +++ b/arch/arm/mach-imx/Makefile
> @@ -59,6 +59,7 @@ ifneq ($(CONFIG_SPL_BUILD),y)
>  obj-$(CONFIG_CMD_BMODE) += cmd_bmode.o
>  obj-$(CONFIG_CMD_HDMIDETECT) += cmd_hdmidet.o
>  obj-$(CONFIG_CMD_DEKBLOB) += cmd_dek.o
> +obj-$(CONFIG_CMD_NANDBCB) += cmd_nandbcb.o
>  endif
>  
>  ifneq ($(CONFIG_BOARD_SIZE_LIMIT),)
> diff --git a/arch/arm/mach-imx/cmd_nandbcb.c b/arch/arm/mach-imx/cmd_nandbcb.c
> new file mode 100644
> index 0000000000..fd3df78fb4
> --- /dev/null
> +++ b/arch/arm/mach-imx/cmd_nandbcb.c
> @@ -0,0 +1,369 @@
> +/*
> + * i.MX6 nand boot control block(bcb).
> + *
> + * Based on the common/imx-bbu-nand-fcb.c from barebox and imx kobs-ng
> + *
> + * Copyright (C) 2017 Jagan Teki <jagan at amarulasolutions.com>
> + * Copyright (C) 2016 Sergey Kubushyn <ksi at koi8.net>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <nand.h>
> +
> +#include <asm/io.h>
> +#include <jffs2/jffs2.h>
> +#include <linux/mtd/mtd.h>
> +
> +#include <asm/mach-imx/imx-nandbcb.h>
> +#include <asm/mach-imx/imximage.cfg>
> +#include <asm/mach-imx/mxs-nand.h>
> +#include <linux/mtd/mtd.h>
> +#include <nand.h>
> +
> +#define BF_VAL(v, bf)		(((v) & bf##_MASK) >> bf##_OFFSET)
> +#define GETBIT(v, n)		(((v) >> (n)) & 0x1)
> +
> +static u8 calculate_parity_13_8(u8 d)
> +{
> +	u8 p = 0;
> +
> +	p |= (GETBIT(d, 6) ^ GETBIT(d, 5) ^ GETBIT(d, 3) ^ GETBIT(d, 2)) << 0;
> +	p |= (GETBIT(d, 7) ^ GETBIT(d, 5) ^ GETBIT(d, 4) ^ GETBIT(d, 2) ^
> +	      GETBIT(d, 1)) << 1;
> +	p |= (GETBIT(d, 7) ^ GETBIT(d, 6) ^ GETBIT(d, 5) ^ GETBIT(d, 1) ^
> +	      GETBIT(d, 0)) << 2;
> +	p |= (GETBIT(d, 7) ^ GETBIT(d, 4) ^ GETBIT(d, 3) ^ GETBIT(d, 0)) << 3;
> +	p |= (GETBIT(d, 6) ^ GETBIT(d, 4) ^ GETBIT(d, 3) ^ GETBIT(d, 2) ^
> +	      GETBIT(d, 1) ^ GETBIT(d, 0)) << 4;
> +
> +	return p;
> +}
> +
> +static void encode_hamming_13_8(void *_src, void *_ecc, size_t size)
> +{
> +	int i;
> +	u8 *src = _src;
> +	u8 *ecc = _ecc;
> +
> +	for (i = 0; i < size; i++)
> +		ecc[i] = calculate_parity_13_8(src[i]);
> +}
> +
> +static u32 calc_chksum(void *buf, size_t size)
> +{
> +	u32 chksum = 0;
> +	u8 *bp = buf;
> +	size_t i;
> +
> +	for (i = 0; i < size; i++)
> +		chksum += bp[i];
> +
> +	return ~chksum;
> +}
> +
> +static void fill_fcb(struct fcb_block *fcb, struct mtd_info *mtd)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct mxs_nand_info *nand_info = nand_get_controller_data(chip);
> +
> +	fcb->fingerprint = FCB_FINGERPRINT;
> +	fcb->version = FCB_VERSION_1;
> +	fcb->pagesize = mtd->writesize;
> +	fcb->oob_pagesize = mtd->writesize + mtd->oobsize;
> +	fcb->sectors = mtd->erasesize / mtd->writesize;
> +
> +	/* Divide ECC strength by two and save the value into FCB structure. */
> +	fcb->ecc_level = nand_info->bch_geometry.ecc_strength >> 1;
> +
> +	fcb->ecc_type = fcb->ecc_level;
> +
> +	/* Also hardcoded in kobs-ng */
> +	fcb->ecc_nr = 0x00000200;
> +	fcb->ecc_size = 0x00000200;
> +	fcb->datasetup = 80;
> +	fcb->datahold = 60;
> +	fcb->addr_setup = 25;
> +	fcb->dsample_time = 6;
> +	fcb->meta_size = 10;
> +
> +	/* DBBT search area starts at second page on first block */
> +	fcb->dbbt_start = 1;
> +
> +	fcb->bb_byte = nand_info->bch_geometry.block_mark_byte_offset;
> +	fcb->bb_start_bit = nand_info->bch_geometry.block_mark_bit_offset;
> +
> +	fcb->phy_offset = mtd->writesize;
> +
> +	fcb->nr_blocks = mtd->writesize / fcb->ecc_nr - 1;
> +
> +	fcb->checksum = calc_chksum((void *)fcb + 4, sizeof(*fcb) - 4);
> +}
> +
> +static int dbbt_fill_data(struct mtd_info *mtd, void *buf, int num_blocks)
> +{
> +	int n, n_bad_blocks = 0;
> +	u32 *bb = buf + 0x8;
> +	u32 *n_bad_blocksp = buf + 0x4;
> +
> +	for (n = 0; n < num_blocks; n++) {
> +		loff_t offset = n * mtd->erasesize;
> +			if (mtd_block_isbad(mtd, offset)) {
> +				n_bad_blocks++;
> +				*bb = n;
> +				bb++;
> +		}
> +	}
> +
> +	*n_bad_blocksp = n_bad_blocks;
> +
> +	return n_bad_blocks;
> +}
> +
> +static int nandbcb_update(struct mtd_info *mtd, loff_t off, size_t size,
> +			  size_t maxsize, const u_char *buf)
> +{
> +	nand_erase_options_t opts;
> +	struct fcb_block *fcb;
> +	struct dbbt_block *dbbt;
> +	loff_t fw1_off;
> +	void *fwbuf, *fcb_raw_page, *dbbt_page, *dbbt_data_page;
> +	int nr_blks, nr_blks_fcb, fw1_blk;
> +	size_t fwsize, dummy;
> +	int i, ret;
> +
> +	/* erase */
> +	memset(&opts, 0, sizeof(opts));
> +	opts.offset = off;
> +	opts.length = maxsize - 1;
> +	ret = nand_erase_opts(mtd, &opts);
> +	if (ret) {
> +		printf("%s: erase failed (ret = %d)\n", __func__, ret);
> +		return ret;
> +	}
> +
> +	/*
> +	 * Reference documentation from i.MX6DQRM section 8.5.2.2
> +	 *
> +	 * Nand Boot Control Block(BCB) contains two data structures,
> +	 * - Firmware Configuration Block(FCB)
> +	 * - Discovered Bad Block Table(DBBT)
> +	 *
> +	 * FCB contains,
> +	 * - nand timings
> +	 * - DBBT search page address,
> +	 * - start page address of primary firmware
> +	 * - start page address of secondary firmware
> +	 *
> +	 * setup fcb:
> +	 * - number of blocks = mtd partition size / mtd erasesize
> +	 * - two firmware blocks, primary and secondary
> +	 * - first 4 block for FCB/DBBT
> +	 * - rest split in half for primary and secondary firmware
> +	 * - same firmware will write two times
> +	 */
> +	nr_blks_fcb = 2;
> +	nr_blks = maxsize / mtd->erasesize;
> +	fw1_blk = nr_blks_fcb;
> +
> +	/* write fw */
> +	fwsize = ALIGN(size + FLASH_OFFSET_STANDARD + mtd->writesize,
> +		       mtd->writesize);
> +	fwbuf = kzalloc(fwsize, GFP_KERNEL);
> +	if (!fwbuf) {
> +		debug("failed to allocate fwbuf\n");
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	memcpy(fwbuf + FLASH_OFFSET_STANDARD, buf, size);
> +	fw1_off = fw1_blk * mtd->erasesize;
> +	ret = nand_write_skip_bad(mtd, fw1_off, &fwsize, NULL, maxsize,
> +				  (u_char *)fwbuf, WITH_WR_VERIFY);
> +	printf("NAND fw write: 0x%llx offset, 0x%x bytes written: %s\n",
> +	       fw1_off, fwsize, ret ? "ERROR" : "OK");
> +	if (ret)
> +		goto fwbuf_err;
> +
> +	/* fill fcb */
> +	fcb = kzalloc(sizeof(*fcb), GFP_KERNEL);
> +	if (!fcb) {
> +		debug("failed to allocate fcb\n");
> +		ret = -ENOMEM;
> +		goto fwbuf_err;
> +	}
> +
> +	fcb->fw1_start = (fw1_blk * mtd->erasesize) / mtd->writesize;
> +	fcb->fw1_pages = size / mtd->writesize + 1;
> +	fill_fcb(fcb, mtd);
> +
> +	/* fill dbbt */
> +	dbbt_page = kzalloc(mtd->writesize, GFP_KERNEL);
> +	if (!dbbt_page) {
> +		debug("failed to allocate dbbt_page\n");
> +		ret = -ENOMEM;
> +		goto fcb_err;
> +	}
> +
> +	dbbt_data_page = kzalloc(mtd->writesize, GFP_KERNEL);
> +	if (!dbbt_data_page) {
> +		debug("failed to allocate dbbt_data_page\n");
> +		ret = -ENOMEM;
> +		goto dbbt_page_err;
> +	}
> +
> +	dbbt = dbbt_page;
> +	dbbt->checksum = 0;
> +	dbbt->fingerprint = DBBT_FINGERPRINT2;
> +	dbbt->version = DBBT_VERSION_1;
> +	ret = dbbt_fill_data(mtd, dbbt_data_page, nr_blks);
> +	if (ret < 0)
> +		goto dbbt_data_page_err;
> +	else if (ret > 0)
> +		dbbt->dbbtpages = 1;
> +
> +	/* write fcb/dbbt */
> +	fcb_raw_page = kzalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
> +	if (!fcb_raw_page) {
> +		debug("failed to allocate fcb_raw_page\n");
> +		ret = -ENOMEM;
> +		goto dbbt_data_page_err;
> +	}
> +
> +	memcpy(fcb_raw_page + 12, fcb, sizeof(struct fcb_block));
> +	encode_hamming_13_8(fcb_raw_page + 12, fcb_raw_page + 12 + 512, 512);
> +	/*
> +	 * Set the first and second byte of OOB data to 0xFF, not 0x00. These
> +	 * bytes are used as the Manufacturers Bad Block Marker (MBBM). Since
> +	 * the FCB is mostly written to the first page in a block, a scan for
> +	 * factory bad blocks will detect these blocks as bad, e.g. when
> +	 * function nand_scan_bbt() is executed to build a new bad block table.
> +	 */
> +	memset(fcb_raw_page + mtd->writesize, 0xFF, 2);
> +
> +	for (i = 0; i < nr_blks_fcb; i++) {
> +		if (mtd_block_isbad(mtd, off)) {
> +			printf("Block %d is bad, skipped\n", i);
> +			continue;
> +		}
> +
> +		/* raw write */
> +		mtd_oob_ops_t ops = {
> +			.datbuf = (u8 *)fcb_raw_page,
> +			.oobbuf = ((u8 *)fcb_raw_page) + mtd->writesize,
> +			.len = mtd->writesize,
> +			.ooblen = mtd->oobsize,
> +			.mode = MTD_OPS_RAW
> +		};
> +
> +		ret = mtd_write_oob(mtd, mtd->erasesize * i, &ops);
> +		if (ret)
> +			goto fcb_raw_page_err;
> +		debug("NAND fcb write: 0x%x offset, 0x%x bytes written: %s\n",
> +		      mtd->erasesize * i, ops.len, ret ? "ERROR" : "OK");
> +
> +		ret = mtd_write(mtd, mtd->erasesize * i + mtd->writesize,
> +				mtd->writesize, &dummy, dbbt_page);
> +		if (ret)
> +			goto fcb_raw_page_err;
> +		debug("NAND dbbt write: 0x%x offset, 0x%x bytes written: %s\n",
> +		      mtd->erasesize * i + mtd->writesize, dummy,
> +		      ret ? "ERROR" : "OK");
> +
> +		/* dbbtpages == 0 if no bad blocks */
> +		if (dbbt->dbbtpages > 0) {
> +			loff_t to = (mtd->erasesize * i + mtd->writesize * 5);
> +
> +			ret = mtd_write(mtd, to, mtd->writesize, &dummy,
> +					dbbt_data_page);
> +			if (ret)
> +				goto fcb_raw_page_err;
> +		}
> +	}
> +
> +fcb_raw_page_err:
> +	kfree(fcb_raw_page);
> +dbbt_data_page_err:
> +	kfree(dbbt_data_page);
> +dbbt_page_err:
> +	kfree(dbbt_page);
> +fcb_err:
> +	kfree(fcb);
> +fwbuf_err:
> +	kfree(fwbuf);
> +err:
> +	return ret;
> +}
> +
> +static int do_nandbcb_update(int argc, char * const argv[])
> +{
> +	struct mtd_info *mtd;
> +	loff_t addr, offset, size, maxsize;
> +	char *endp;
> +	u_char *buf;
> +	int dev;
> +	int ret;
> +
> +	if (argc != 4)
> +		return CMD_RET_USAGE;
> +
> +	dev = nand_curr_device;
> +	if (dev < 0) {
> +		printf("failed to get nand_curr_device, run nand device");
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	addr = simple_strtoul(argv[1], &endp, 16);
> +	if (*argv[1] == 0 || *endp != 0)
> +		return CMD_RET_FAILURE;
> +
> +	mtd = get_nand_dev_by_index(dev);
> +	if (mtd_arg_off_size(argc - 2, argv + 2, &dev, &offset, &size,
> +			     &maxsize, MTD_DEV_TYPE_NAND, mtd->size))
> +		return CMD_RET_FAILURE;
> +
> +	buf = map_physmem(addr, size, MAP_WRBACK);
> +	if (!buf) {
> +		puts("failed to map physical memory\n");
> +		return CMD_RET_FAILURE;
> +	}
> +
> +	ret = nandbcb_update(mtd, offset, size, maxsize, buf);
> +
> +	return ret == 0 ? CMD_RET_SUCCESS : CMD_RET_FAILURE;
> +}
> +
> +static int do_nandbcb(cmd_tbl_t *cmdtp, int flag, int argc,
> +		      char * const argv[])
> +{
> +	const char *cmd;
> +	int ret = 0;
> +
> +	if (argc < 5)
> +		goto usage;
> +
> +	cmd = argv[1];
> +	--argc;
> +	++argv;
> +
> +	if (strcmp(cmd, "update") == 0) {
> +		ret = do_nandbcb_update(argc, argv);
> +		goto done;
> +	}
> +
> +done:
> +	if (ret != -1)
> +		return ret;
> +usage:
> +	return CMD_RET_USAGE;
> +}
> +
> +static char nandbcb_help_text[] =
> +	"update addr off|partition len	- update 'len' bytes starting at\n"
> +	"	'off|part' to memory address 'addr', skipping  bad blocks";
> +
> +U_BOOT_CMD(nandbcb, 5, 1, do_nandbcb,
> +	   "i.MX6 Nand BCB",
> +	   nandbcb_help_text
> +);
> diff --git a/doc/imx/common/imx6.txt b/doc/imx/common/imx6.txt
> index eab88353f6..5a354005f8 100644
> --- a/doc/imx/common/imx6.txt
> +++ b/doc/imx/common/imx6.txt
> @@ -88,3 +88,78 @@ Reading bank 4:
>  
>  Word 0x00000002: 9f027772 00000004
>  
> +
> +NAND Boot on i.MX6 with SPL support
> +--------------------------------------
> +
> +Writing/updating boot image in nand device is not straight forward in
> +i.MX6 platform and it requires boot control block(BCB) to be configured.
> +
> +BCB contains two data structures, Firmware Configuration Block(FCB) and
> +Discovered Bad Block Table(DBBT). FCB has nand timings, DBBT search area,
> +and firmware. See IMX6DQRM Section 8.5.2.2
> +for more information.
> +
> +We can't use 'nand write' command to write SPL/firmware image directly
> +like other platforms does. So we need special setup to write BCB block
> +as per IMX6QDL reference manual 'nandbcb update' command do that job.
> +
> +for nand boot, up on reset bootrom look for FCB structure in
> +first block's if FCB found the nand timings are loaded for
> +further reads. once FCB read done, DTTB will be loaded and
> +finally firmware will be loaded which is boot image.
> +
> +cmd_nandbcb will create FCB these structures
> +by taking mtd partition as an example.
> +- initial code will erase entire partition
> +- followed by FCB setup, like first 2 blocks for FCB/DBBT write,
> +  and next block for FW1/SPL
> +- write firmware at FW1 block and
> +- finally write fcb/dttb in first 2 block.
> +
> +Typical NAND BCB layout:
> +=======================
> +
> +   no.of blocks = partition size / erasesize
> +   no.of fcb/dbbt blocks = 2
> +   FW1 offset = no.of fcb/dbbt
> +
> +block  0          1          2
> +        -------------------------------
> +       |FCB/DBBT 0|FCB/DBBT 1|  FW 1  |
> +       --------------------------------
> +
> +On summary, nandbcb update will
> +- erase the entire partition
> +- create BCB by creating 2 FCB/BDDT block followed by
> +  1 FW blocks based on partition size and erasesize.
> +- fill FCB/DBBT structures
> +- write FW/SPL in FW1
> +- write FCB/DBBT in first 2 blocks
> +
> +step-1: write SPL
> +
> +icorem6qdl> fatload mmc 0:1 $loadaddr SPL
> +reading SPL
> +31744 bytes read in 15 ms (2 MiB/s)
> +
> +icorem6qdl> nandbcb update $loadaddr spl $filesize
> +device 0 offset 0x0, size 0x7c00
> +Erasing at 0x1c0000 -- 100% complete.
> +NAND fw write: 0x100000 offset, 0x9000 bytes written: OK
> +NAND fw write: 0x180000 offset, 0x9000 bytes written: OK
> +
> +step-2: write u-boot-dtb.img
> +
> +icorem6qdl> nand erase.part uboot
> +NAND erase.part: device 0 offset 0x200000, size 0x200000
> +Erasing at 0x3c0000 -- 100% complete.
> +OK
> +
> +icorem6qdl> fatload mmc 0:1 $loadaddr u-boot-dtb.img
> +reading u-boot-dtb.img
> +508967 bytes read in 48 ms (10.1 MiB/s)
> +
> +icorem6qdl> nand write ${loadaddr} uboot ${filesize}
> +NAND write: device 0 offset 0x200000, size 0x7c427
> +508967 bytes written: OK
> diff --git a/drivers/mtd/nand/raw/mxs_nand.c b/drivers/mtd/nand/raw/mxs_nand.c
> index b93d77a395..91dcbc4d22 100644
> --- a/drivers/mtd/nand/raw/mxs_nand.c
> +++ b/drivers/mtd/nand/raw/mxs_nand.c
> @@ -25,7 +25,7 @@
>  #include <asm/mach-imx/regs-bch.h>
>  #include <asm/mach-imx/regs-gpmi.h>
>  #include <asm/arch/sys_proto.h>
> -#include "mxs_nand.h"
> +#include <asm/mach-imx/mxs-nand.h>
>  
>  #define	MXS_NAND_DMA_DESCRIPTOR_COUNT		4
>  
> diff --git a/drivers/mtd/nand/raw/mxs_nand_spl.c b/drivers/mtd/nand/raw/mxs_nand_spl.c
> index ee7d9cb957..1f072721aa 100644
> --- a/drivers/mtd/nand/raw/mxs_nand_spl.c
> +++ b/drivers/mtd/nand/raw/mxs_nand_spl.c
> @@ -6,7 +6,8 @@
>  #include <common.h>
>  #include <nand.h>
>  #include <malloc.h>
> -#include "mxs_nand.h"
> +#include <asm/mach-imx/mxs-nand.h>
> +
>  
>  static struct mtd_info *mtd;
>  static struct nand_chip nand_chip;
> 

-- 
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HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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