The “Boot from removable storage- Ubuntu” documentation contains a reference to the environment variable bootmmc. It appears that the two strings mentioned are identical. What are the bootmmc variable for the various boot scenarios?
Next we setup the boot command by changing the bootmmc variable. We will use this variable to boot the microSD card:
Marvell>> setenv bootmmc ‘mmc dev 0; ext4load mmc 0:1 $kernel_addr $image_name;ext4load mmc 0:1 $fdt_addr $fdt_name;setenv bootargs $console root=/dev/mmcblk0p1 rw rootwait; booti $kernel_addr – $fdt_addr’
Be careful to set the root path above to point to where you have extracted the Ubuntu file system (in our case we copied it to the first partition).
After this we can save the variables we have set so far:
Marvell>> save
or setup the bootcmd variable for the ESPRESSObin to automatically boot with the desired variables:
Marvell>> setenv bootcmd ‘mmc dev 0; ext4load mmc 0:1 $kernel_addr $image_name;ext4load mmc 0:1 $fdt_addr $fdt_name;setenv bootargs $console root=/dev/mmcblk0p1 rw rootwait; booti $kernel_addr – $fdt_addr’