scratch that.
it seems the u-boot is fine. managed to start the board with it
EEEE I3000000032940xf100110003877500EEEE I400000004294_M8_BL1_10221D113B323EEEE I400000004294enter usb bootA1A13697EEEE I3000000032940xdd00000103974545EEEE I600000006294No boot up devic5
no sdio debug board detected
TE : 472102
BT : 19:06:30 Apr 4 2017
PMU:rn5t618
DC01 v:1100, 0x[36]: 18 -> 28
DC02 v:1150, 0x[37]: 18 -> 2c
DC03 v:1500, 0x[38]: 38 -> 48
LDO01 v:2900, 0x[4c]: 4e -> 50
LDO02 v:1800, 0x[4d]: 24 -> 24
LDO03 v:1800, 0x[4e]: 30 -> 30
LDO04 v:2850, 0x[4f]: 4e -> 4e
LDO05 v:1800, 0x[50]: 24 -> 24
LDO0a v:2700, 0x[56]: 28 -> 28
LDO0b v:900, 0x[57]: 00 -> 00
CPU clock is 1200MHz
CPU type: M8
DDR info: 2GB(auto) @ 792MHz(1T)
DDR channel: DDR 0 + DDR 1
DDR init use : 12123 us
HHH
0x0000008d
check SD_boot_type:0x1 card_type:0x1
ucl decompress...pass
0x12345678
Boot from external device
TE : 805512
System Started
U-boot(m8_k200_v1@) (Apr 04 2017 - 19:06:21)
clr h-ram
DRAM: 2 GiB
-- so, u-boot seems fine there.
there's still a long way to having a system up and running (with XBMC, for example) so I'm still hoping you could help.
let me know if you need any info .
cheers