I have to start u-boot on a new board, unfortunately the design was not based upon usual dev-boards...
It uses two MT42L128M32D1 LPDDR2 SRAMs on iMX6DL, one for low word DRAM_D0..31 on port 0 and the other one for the high word DRAM_D32..63 at port 1.
I cannot find the right configuration option for that or an appropriate DDR config Excel sheet.
And finally the promising LPDDR stress test tools, provided here, are using UART1 but my design uses uses UART5 on CSI0_DAT14 (TX) CSI0_DAT15 (RX).
There is a second design using the same basics, but is equipped with iMX6S and only port 0 has a MT42L128M32D1 placed but it uses UART5 too.