Optimize use of system and secondary disks

Use eMMC as your system disk.
Not all systems support eMMC, but where possible, use eMMC to optimize your boot time. In your buildfile, ensure that you include a script section to start the appropriate driver for your target hardware. For example:
[+script] .script = {
    display_msg Starting eMMC as system disk /dev/sysdisk0 ...
    # START eMMC
    devb-sdmmc-omap_generic blk noatime,cache=8M,automount=@/proc/boot/automount cam cache,async,quiet\z
sdio hc=omap,addr=0x480B4000,irq=118,clk=96000000 dos exe=all disk name=sysdisk &
For more information on how to copy the IFS to the eMMC, see the “Copying the IFS image to the eMMC” section of the Prepare boot images chapter of the BSP User's Guide for your platform.
Enable fast reading in the SD card.
Reading from an SD card is much slower than reading from disk. Modify the SD card driver to enable fast reading to reduce the time it takes to read the image from the card