Hello to everyone.
I designed a custom board with AllWinner A31s. I referenced BPI-M2-V3_1 open source schemas. The PCBs were produced and I placed the materials. I had a soldering problem for a while.then 3 boards worked without problems.
I used the axp221s power chip. The voltages on the pcb are correct(and I can change the voltage values with Uboot). I connected the computer with usb. I have previously compiled linux-sunxi sun6i uboot(I did not change any settings). I use the sunxi tools to install uboot. Using sunxi-fel, I tried loading uboot like this:
sunxi-fel.exe uboot u-boot-sunxi-with-spl.bin
but the error was in case of ram init. Data coming from uart debug :
U-Boot SPL 2017.11 (Feb 03 2018 - 12:58:59)
DRAM:Training error initialising DRAM
I added printf to debug uboot source code, and I compiled again. I see the reset in mctl_channel_init function.
I using 2 x 256MB IS43TR16128B-125KBL DDR3 1.5v DDR3 reference voltage ~0.750v
I use 256MB of NAND flash. My next target is to boot using nand flash.But I did not finish the ram end. Can you help me? Is the problem hardware or software? Are there places I need to organize in uboot source code? thank you everyone…