ん－む、U-bootのデバッグメッセージを表示させることができればもうちょい何が問題かを掴めそうな気がするんだけどなあ

Mango Pi MQ-Quad(Allwinner H618)
[119]DRAM_VCC set to 1500 mv
[124]write_leveling error
（略）
[293]read_calibration error
[295]retraining final error
[302][AUTO DEBUG]16 bit,2 ranks training success!
[313]DRAM CLK =720 MHZ
[315]DRAM Type =3 (3:DDR3,4:DDR4,7:LPDDR3,8:LPDDR4)
[323]Actual DRAM SIZE =1024 M
[326]DRAM SIZE =1024 MBytes, para1 = 30fa, para2 = 4001001, dram_tpr13 = 6041
[339]DRAM simple test OK.

Orange Pi Zero2(Allwinner H616)
[113]DRAM_VCC set to 1500 mv
[118]read_calibration error
（略）
[170]read_calibration error
[173]retraining final error
[179][AUTO DEBUG]32bit,1 ranks training success!
[191]DRAM CLK =720 MHZ
[193]DRAM Type =3 (3:DDR3,4:DDR4,7:LPDDR3,8:LPDDR4)
[201]Actual DRAM SIZE =1024 M
[204]DRAM SIZE =1024 MBytes, paradram_tpr13 = 6041
[217]DRAM simstandby flag is 0x0, super standby flag is 0x0
[225]dram size =1024