Where do the extra NAND partitions come from?

Hi Matt,

The function that creates the MTD partitions is located inside drivers/mtd/mtdparts.c:

/*
 * This function, given a master MTD object and a partition table, creates
 * and registers slave MTD objects which are bound to the master according to
 * the partition definitions.
 *
 * We don't register the master, or expect the caller to have done so,
 * for reasons of data integrity.
 */

int add_mtd_partitions(struct mtd_info *master,
               const struct mtd_partition *parts,
               int nbparts)
{
    struct mtd_part *slave;
    uint64_t cur_offset = 0;
    int i;

    printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);

    for (i = 0; i < nbparts; i++) {
        slave = allocate_partition(master, parts + i, i, cur_offset);
        if (IS_ERR(slave))
            return PTR_ERR(slave);

        mutex_lock(&mtd_partitions_mutex);
        list_add(&slave->list, &mtd_partitions);
        mutex_unlock(&mtd_partitions_mutex);

        add_mtd_device(&slave->mtd);

        cur_offset = slave->offset + slave->mtd.size;
    }

    return 0;
}

It should be called passing the partition table from the board-am335xevm.c board file:

/* NAND partition information */
static struct mtd_partition am335x_nand_partitions[] = {
/* All the partition sizes are listed in terms of NAND block size */
    {
        .name           = "SPL",
        .offset         = 0,            /* Offset = 0x0 */
        .size           = SZ_128K,
    },
    {
        .name           = "SPL.backup1",
        .offset         = MTDPART_OFS_APPEND,    /* Offset = 0x20000 */
        .size           = SZ_128K,
    },
    {
        .name           = "SPL.backup2",
        .offset         = MTDPART_OFS_APPEND,    /* Offset = 0x40000 */
        .size           = SZ_128K,
    },
    {
        .name           = "SPL.backup3",
        .offset         = MTDPART_OFS_APPEND,    /* Offset = 0x60000 */
        .size           = SZ_128K,
    },
    {
        .name           = "U-Boot",
        .offset         = MTDPART_OFS_APPEND,   /* Offset = 0x80000 */
        .size           = 15 * SZ_128K,
    },
    {
        .name           = "U-Boot Env",
        .offset         = MTDPART_OFS_APPEND,   /* Offset = 0x260000 */
        .size           = 1 * SZ_128K,
    },
    {
        .name           = "Kernel",
        .offset         = MTDPART_OFS_APPEND,   /* Offset = 0x280000 */
        .size           = 40 * SZ_128K,
    },
    {
        .name           = "File System",
        .offset         = MTDPART_OFS_APPEND,   /* Offset = 0x780000 */
        .size           = MTDPART_SIZ_FULL,
    },
};

Have you done any modifications to the source code? Please make sure that this is the correct structure that is used inside the evm_nand_init() function inside the board file.

Are you using an IDE/indexer (i.e. CCS5)? I strongly recommend using one, since it will help you traverse faster through the source code.

You should check why the "nbparts" argument to the add_mtd_partitions() function is greater than it should be.

Best regards,
Miroslav

I'm using the linux tree found in the sitara_board_port_linux directory under the board port labs. I checked out the 06.00.00.00-nand16 tag and built from that. In the instructions for the board port lab it also shows these partitions under the section "Flashing the File System to NAND with UBIFS" at 

http://processors.wiki.ti.com/index.php/Sitara_Linux_Training:_Boot_Time_Reduction

So I think this is a normal part of this build. I just want to rearrange the partitions a bit, but I can't do that until I find out where they are being defined.

I checked the board_am335xevm.c file and it definitely passes the same parameters you show above...

Sorry, I was looking at the wrong git tag before. Thanks.