[U-Boot] Info on NAND-SPL

[Hatim Ali]

Hello, 
 
I was trying to understand how NAND-SPL works. What I could understand after seeing the code is that 
1) NAND-SPL is a standalone application which will load the U-boot in the main memory. 
2) After doing the clock and DRAM initialization it will relocate itself in the DRAM. 
3) Then it will copy the u-boot from the nand into the RAM and execute the u-boot. 
 
If my understanding is proper, then I have one doubt 
1) Since the nand_spl is making use of the same Start.S and lowlevel_init.S, the u-boot code will also perform relocation? So is it not a overhead doing relocation twice? 
 
Also is there any similar implementation for MMC-SPL? 
 
Thanks 
Hatim