Erase eMMC

u-boot=> mmc list

FSL_SDHC: 1 (SD)
FSL_SDHC: 2

u-boot=> mmc dev 2 0

switch to partitions #0, OK
mmc2(part 0) is current device

u-boot=> mmc part

Partition Map for MMC device 2  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
  1     16384           131072          e1f87b96-01     0c Boot
  2     147456          30629888        e1f87b96-02     83
  3     4341760         20480           e1f87b96-03     83
  4     4362240         24997888        e1f87b96-04     05 Extd
bad MBR sector signature 0x0000

u-boot=> mmc read ${loadaddr} 0x7fffffff 1

MMC read: dev # 2, block # 2147483647, count 1 ... MMC: block number 0x80000000 exceeds max(0x1d5a000)
0 blocks read: ERROR

u-boot=> mmc erase 0 0x1d5a000

MMC erase: dev # 2, block # 0, count 30777344 ... 30777344 blocks erased: OK

u-boot=> mmc dev 2 1

switch to partitions #1, OK
mmc2(part 1) is current device

u-boot=> mmc read ${loadaddr} 0x7fffffff 1

MMC read: dev # 2, block # 2147483647, count 1 ... MMC: block number 0x80000000 exceeds max(0x2000)
0 blocks read: ERROR

u-boot=> mmc erase 0 0x2000

MMC erase: dev # 2, block # 0, count 8192 ... 8192 blocks erased: OK

u-boot=> mmc dev 2 2

switch to partitions #2, OK
mmc2(part 2) is current device

u-boot=> mmc read ${loadaddr} 0x7fffffff 1

MMC read: dev # 2, block # 2147483647, count 1 ... MMC: block number 0x80000000 exceeds max(0x2000)
0 blocks read: ERROR

u-boot=> mmc erase 0 0x2000

MMC erase: dev # 2, block # 0, count 8192 ... 8192 blocks erased: OK

u-boot=> mmc part

Partition Map for MMC device 2  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
bad MBR sector signature 0x0000
u-boot=>