AM6422: lpDDR configuration issue

You will need to make other changes in the u-boot device tree due to the reduced DDR size.  Please see: https://dev.ti.com/tirex/explore/content/am64x_academy_10_01_00_00/_build_am64x_academy_10_01_00_00/source/linux/ch-porting/porting-uboot.html#modifying-ram-size

Regards,

James

hi JJD,

Thanks a lot, I have modified the dts file, but it does not work well.

I am using TI u-boot2024.04, I have modified the "arch/arm/dts/k3-am642-evm.dts" as flowing:

memory@80000000 {
bootph-all;
device_type = "memory";
- /* 2G RAM */
- reg = <0x00000000 0x80000000 0x00000000 0x80000000>;
+ /* 512MB RAM */
+ reg = <0x00000000 0x80000000 0x00000000 0x20000000>; /* Neal: MCE uses 512MB DDR */
};

And I did not find any r5 dts including memory@80000000 ,so I can only modify k3-am642-evm.dts

the below picture is test result, the u-boot.img will hang after printing DRMA: 512 MiB

After you rebuild your code, ensure that you replace all three files on the SD card: tiboot3.bin, tispl.bin, u-boot.img.  It appears that your u-boot build date still shows Mar 27

Regards,

James

yes ,I am sure that I have replaced all three files:tiboot3.bin, tispl.bin, u-boot.img

Ok , please provide the full boot log, so we can see everything that is booting.  What is your boot sequence (ie what are your BOOTMODE signals set to)?  from the log it appears you are booting from DFU.  

Regards,

James

Thanks, I found that if adding CONFIG_SYS_MEM_TOP_HIDE=0x4000000 in  src/patches/am64x_evm_a53_defconfig , the u-boot can works well.

I don't konw why ?

this is the refference link AM623: uboot can‘t boot normally in our customer board - Processors forum - Processors - TI E2E support forums

Ok, good, let me try to get an explanation for you.  I think the issue is that certain boot components are relocated to upper memory, but when the DDR size is reduced, that "upper" memory needs to be moved lower due to the reduced DDR capacity.  

Regards,

James

thanks a lot for deeply analysis.