Marcos,
In the AN 542 DM3730 - AM3703 SOM Programming for End-Product Manufacturing, Section 10.3.7 Update MLO, U-Boot, Kernel, and Root Filesystem, provides the command from the Linux terminal for programming MLO.
DM-37x flashtool -w -e --all-blocks --hamming /dev/mtd0 /mnt/nfs-usb/linux-demo/MLO
If flashtool is available, it could be a solution for updating MLO from the Linux terminal.
Thanks,
Brad