Update eMMC with Yocto firmware

1. Partition the eMMC for holding Yocto images by running:

   => setenv mmcdev 0
   => run partition_mmc_linux

2. Check the partition table created on the eMMC by running the mmc part command.

   => mmc part
   Partition Map for MMC device 0  --   Partition Type: EFI
   Part   Start LBA     End LBA       Name
   Attributes       Type UUID
   Partition UUID
   1    0x00001000    0x00020fff    "linux"
   attrs:  0x0000000000000000
   type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
   uuid:   43f1961b-ce4c-4e6c-8f22-2230c5d532bd
   2    0x00021000    0x00040fff    "linux2"
   attrs:  0x0000000000000000
   type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
   uuid:   f241b915-4241-47fd-b4de-ab5af832a0f6
   3    0x00041000    0x00240fff    "rootfs"
   attrs:  0x0000000000000000
   type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
   uuid:   1c606ef5-f1ac-43b9-9bb5-d5c578580b6b
   4    0x00241000    0x00440fff    "rootfs2"
   attrs:  0x0000000000000000
   type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
   uuid:   c7d8648b-76f7-4e2b-b829-e95a83cc7b32
   5    0x00441000    0x0075ffde    "userfs"
   attrs:  0x0000000000000000
   type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
   uuid:   ebae5694-6e56-497c-83c6-c4455e12d727

Five partitions are created in anticipation of holding a redundant system:

• linux: To hold the kernel and device tree images.
• linux2: To hold a copy (or alternative) kernel and device tree images.
• rootfs: To hold the root file system.
• rootfs2: To hold a copy (or alternative) root file system.
• userfs: To hold user data.

Note The command only creates the partition table. Partitions are unformatted.

3. Write the desired file *.vfat to eMMC partition linux either from TFTP or a FAT formatted microSD card:
   • From TFTP (assuming the file is on the TFTP server's exposed folder):

     => update linux tftp <filename>.vfat

   • From a FAT formatted microSD card (where you previously copied the file):

     => update linux mmc 1 fat <filename>.vfat

4. Write the desired file *.ext4 to eMMC partition rootfs either from TFTP or a FAT formatted microSD card:
   • From TFTP (assuming the file is on the TFTP server's exposed folder):

     => update rootfs tftp <filename>.ext4

   • From a FAT formatted microSD card (where you previously copied the file):

     => update rootfs mmc 1 fat <filename>.ext4

The new firmware is now ready on the eMMC. Default video output is HDMI.

5. Change the default boot command in U-Boot to boot the device from the eMMC:

   => setenv bootcmd dboot linux mmc
   => saveenv

6. Reset the board and let it boot automatically.