beaglebon black Emmc partitions & update

Dear Sir

  1. I want to know the Beaglebone black’s 2GB EMMC partition ,EX:

SPL Start Address - End Address
UBOOT …
KERNEL…
ROOTFS…

2.How do I update these partitions one by one using uboot? EX:

U-Boot# loadb 0x82000000
…download bin/img to SDRAM
U-Boot# nand erase 0x0 0x20000
U-Boot# nand write 0x82000000 0x0 0x20000

thanks a lot…!!