Finally got the converter. Here is the result:
HELLO! BOOT0 is starting!
boot0 commit : 82a2e49cc2a78c99a14cb67b3cb4284805382f0c
boot0 version : 4.0
set pll start
set pll end
rtc[0] value = 0x00000000
rtc[1] value = 0x00000000
rtc[2] value = 0x00000000
rtc[3] value = 0x00000000
rtc[4] value = 0x00000000
rtc[5] value = 0x00000000
DRAM BOOT DRIVE INFO: V0.6
the chip id is 0x00000001
the chip id is 0x00000001
the chip id is 0x00000001
the chip id is 0x00000001
the chip id is 0x00000001
axp not exist
DRAM CLK =624 MHZ
DRAM Type =3 (2:DDR2,3:DDR3,6:LPDDR2,7:LPDDR3)
DRAM zq value: 0x003b3bf9
DRAM SIZE =2048 M
DRAM simple test OK.
dram size =2048
card no is 0
sdcard 0 line count 4
[mmc]: mmc driver ver 2016-03-15 20:40
[mmc]: sdc0 spd mode error, 2
[BUDDY] CARD_TYPE 0
[mmc]: Wrong media type 0x00000000
[mmc]: ***Try SD card 0***
[mmc]: HSSDR52/SDR25 4 bit
[mmc]: 50000000 Hz
[mmc]: 30436 MB
[mmc]: ***SD/MMC 0 init OK!!!***
[MMC] BLCOK ARG:cmd.cmdidx 18
[MMC] BLCOK ARG:cmd.resp_type 21
[MMC] BLCOK ARG:cmd.flags 0
[MMC] BLCOK ARG:data.block 64
[MMC] BLCOK ARG:data.blocksize 512
[MMC] BLCOK ARG:data.flags 1
[MMC] BLCOK ARG:cmd.cmdarg 32800
[BUDDY2] nectblck net
[MMC2] BLCOK ARG:cmd.cmdidx 12
[MMC2] BLCOK ARG:cmd.resp_type 29
[MMC2] BLCOK ARG:cmd.flags 0
[MMC2] BLCOK ARG:data.block 64
[MMC2] BLCOK ARG:data.blocksize 512
[MMC2] BLCOK ARG:data.flags 1
[MMC2] BLCOK ARG:cmd.cmdarg 0
[MMC] BLCOK ARG:cmd.cmdidx 18
[MMC] BLCOK ARG:cmd.resp_type 21
[MMC] BLCOK ARG:cmd.flags 0
[MMC] BLCOK ARG:data.block 2176
[MMC] BLCOK ARG:data.blocksize 512
[MMC] BLCOK ARG:data.flags 1
[MMC] BLCOK ARG:cmd.cmdarg 32864
[BUDDY2] nectblck net
[MMC2] BLCOK ARG:cmd.cmdidx 12
[MMC2] BLCOK ARG:cmd.resp_type 29
[MMC2] BLCOK ARG:cmd.flags 0
[MMC2] BLCOK ARG:data.block 2176
[MMC2] BLCOK ARG:data.blocksize 512
[MMC2] BLCOK ARG:data.flags 1
[MMC2] BLCOK ARG:cmd.cmdarg 0
sum=9286958d
src_sum=e28ddf42
Fail in checking uboot.
[MMC] BLCOK ARG:cmd.cmdidx 18
[MMC] BLCOK ARG:cmd.resp_type 21
[MMC] BLCOK ARG:cmd.flags 0
[MMC] BLCOK ARG:data.block 64
[MMC] BLCOK ARG:data.blocksize 512
[MMC] BLCOK ARG:data.flags 1
[MMC] BLCOK ARG:cmd.cmdarg 24576
[BUDDY2] nectblck net
[MMC2] BLCOK ARG:cmd.cmdidx 12
[MMC2] BLCOK ARG:cmd.resp_type 29
[MMC2] BLCOK ARG:cmd.flags 0
[MMC2] BLCOK ARG:data.block 64
[MMC2] BLCOK ARG:data.blocksize 512
[MMC2] BLCOK ARG:data.flags 1
[MMC2] BLCOK ARG:cmd.cmdarg 0
PANIC : sunxi_flash_init() error --2--,toc1 magic error
PANIC : sunxi_flash_init() error --0--
Ready to disable icache.
Duckduckgoing didn't fetch me anything useful fo "Fail in checking uboot" nor "toc1 magic error". It looks like it's seeing the SD card properly, but then hits kernel panic. I'm guessing toc1 has something to do with the CPU.