This can be achieved by adding parameters to the u-boot environment variables.

(Step 1) Display the U-boot prompt

1. Enter any key within 5 seconds to activate the u-boot console.

(Step 2) Edit u-boot environment variables

1. Execute the following command to edit "mmcboot".
   The following example shows a setting that passes only 512MB to Linux.
   
   #editenv mmcboot
   setenv bootargs console=ttyS0,57600 root=${mmcroot} rw rootwait mem=512M;bootm ${loadaddr} - ${fdtaddr}
   (mem=512M parameter added)
   
   *You can check whether the settings have been reflected by using the printenv command.
   * Parameters can be saved by using the saveenv command.

(Step 3) Starting Linux

1. Run the boot command to boot Linux.