The normal boot process is , SPL is loaded to the SRAM and during the execution of the SPL DDR Ram gets initialized.
Once the DDR is initialized , u-boot /kernel is loaded to DDR Ram.
Now SPL is no longer in use and CPU directly loads the u-boot to DRAM. Now question is , where the DDR Ram gets initialized ? IMX can load u-boot only when the DDR ram is initialized. Where this initialization happens ?