SPI NOR Partitioning and read/write from u-boot C code

Question

We have BBB based custom board,
we have SPI NOR flash and NAND flash on the board,
We were able to make mtd partitions for NAND. But NOR partitioning is not working :(
we added following defines to make mtd NOR partitions.

#define MTDIDS_DEFAULT "nand0=omap2-nand.0, nor0=omap2-nor.0"
#define MTDPARTS_DEFAULT "mtdparts=omap2-nand.0:" \
"128k(SPL)," \
"128k(SPL.backup1)," \
"128k(SPL.backup2)," \
"128k(SPL.backup3)," \
"1024k(u-boot)," \
"1024k(u-boot.backup1)," \
"128k(u-boot-env)," \
"5m(kernel)," \
"5m(kernel.backup1)," \
"512k(fdt)," \
"512k(fdt.backup1)," \
"100m(rootfs)," \
"100m(rootfs.backup1)," \
"13m(reserved)," \
";" \
"mtdparts=omap2-nor.0:" \
"128k(SPL1_nor)," \
"128k(SPL2_nor)," \
"128k(SPL3_nor)," \
"128k(SPL4_nor)," \
"512k(usr_nor)," \

Another doubt is, Is it possible to do read/write using mtd device files in u-boot ?
As i understand it, u-boot also uses Linux's mtd drivers, so
Is it possible to do something like fd = open("/dev/mtd0",O_WRONLY) from u-boot code ?

Answer 1

In order to allow partitioning the SPI NOR, I added the following at the end of spi_flash_probe():

/* Release spi bus */
spi_release_bus(spi);

extern nand_info_t nand_info[];
struct mtd_info *mtd;

mtd = &nand_info[1];
mtd->name = "nor0";
mtd->size = flash->size;
mtd->erasesize = flash->erase_size;
mtd->writesize = flash->page_size;
mtd->priv = flash;
mtd->_write = sf_mtdwrite;
mtd->_read = sf_mtdread;
mtd->_erase = sf_mtderase;
#ifdef CONFIG_MTD_DEVICE
add_mtd_device(mtd);
#endif

return flash;

However there is no concept of, e.g., "reading/writing/erasing a partition", these exist separately for NAND and SPIFLASH. So, defining a partition on the SPI NOR is not very useful, except if a generic mtd command (mtd write, mtd read, mtd erase...) is to be created.