Artesyn COMX-P4080 Installation and Use (August 2014) - Manual (Page 118)

BSP Operations
COMX-P4080 COM Express Module Installation and Use (6806800L20C) 118
setenv bootargs root=/dev/$mmcbdev rw rootdelay=30
console=$consoledev,$baudrate $hwbootargs
$othbootargs;mmcinfo;ext2load mmc 0:2 $loadaddr
/boot/$bootfile;ext2load mmc 0:2 $fdtaddr /boot/$fdtfile;bootm
$loadaddr - $fdtaddr
The "mmcfatboot" will load Linux kernel and DTB from the FAT partition (1st partition) on
MMC/SDHC card into RAM and then boot. EXT2 partition (2nd partition) will mount on this
card as rootfs.
"mmcext2boot" will load Linux kernel and DTB from the EXT2 partition (2nd partition) on
MMC/SDHC card into RAM and then boot. The same partition will mount on this card as rootfs.
The following are the critical environment variables for "mmcfatboot" and "mmcext2boot".
Below are examples of critical environment variables.
Similar to the USB drive, users need to create two partitions on the MMC/SDHC card. FAT32 is
the first partition and the EXT2 is the second partition. Both partitiions contain a directory
/boot/ and the directory has kernel DTB files. EXT2 partition contains the rootfs which can be
from rootfs_nfs.tar.gz.
bootfile - Linux kernel file name
fdtfile - DTB file name
=> setenv bootfile COMX_P4080_V100R00/uImage
=> setenv fdtfile COMX_P4080_V100R00/comx.dtb