I have a custom board based on iMX6ull14x14evk, but with 256MB of RAM.
I'm using yocto for iMX6, i'm able to compile and flash the sd card, but I can't change the DRAM size from 512 to 256 MB.
I have tried to modify "mx6ullevk.h" file changing phys dram size define as follows
#define PHYS_SDRAM_SIZE SZ_256M
But when I boot the board the size doesn't change:
CPU: Freescale i.MX6ULL rev1.0 528 MHz (running at 396 MHz)
CPU: Commercial temperature grade (0C to 95C) at 38C
Reset cause: POR
Model: Freescale i.MX6 ULL 14x14 EVK Board
Board: MX6ULL 14x14 EVK
DRAM: 512 MiB
MMC: FSL_SDHC: 0, FSL_SDHC: 1
*** Warning - bad CRC, using default environment
Is there a guide I can follow that shows how to correctly patch the files?