I decided to check the latest linux-next tree for signs of Odroid C2 code, and there is some there – apparently for basic functionality..     Compiled OK, but when I tried to boot it, the Hardkernel-supplied version of U-Boot crashed:

odroidc2#ext4load mmc 0:1 ${loadaddr} /boot/uboot/Image
7748608 bytes read in 187 ms (39.5 MiB/s)
odroidc2#ext4load mmc 0:1 ${dtb_loadaddr} /boot/uboot/meson-gxbb-odroidc2.dtb
27913 bytes read in 5 ms (5.3 MiB/s)
odroidc2#booti ${loadaddr} - ${dtb_loadaddr}
"Synchronous Abort" handler, esr 0x96000010
ELR: 77f4b734
LR: 77f4b728
x0 : 0000000077fa6c48 x1 : 0000000000080000
x2 : 000000000079b000 x3 : 000000000079b000
x4 : 000000000000006e x5 : 0000000011000000
x6 : 0000000077fa6b08 x7 : 0000000000000044
x8 : 0000000077f9a280 x9 : 0000000000000000
x10: 0000000073f386d8 x11: 0000000077f87000
x12: 000000000000000f x13: 0000000000000000
x14: 0000000000000000 x15: 0000000000000000
x16: 0000000000000000 x17: 0000000000000000
x18: 0000000073f38e28 x19: 0000000077fa6b08
x20: 0000000011000000 x21: 0000000073f3e6c0
x22: 0000000000000003 x23: 0000000073f3e6c8
x24: 0000000000000000 x25: 0000000077f9c2c0
x26: 0000000000000000 x27: 0000000000000000
x28: 0000000000000000 x29: 0000000073f38940

I then searched for a more ‘mainline’ version of U-Boot for the C2 and found some fairly recent patches mentioned here: http://permalink.gmane.org/gmane.comp.boot-loaders.u-boot/256647/

I created a patch (from the original newsgroup version of the message, rather than the – mangled – web text) and applied it to the latest -rc version of U-Boot..

After commenting out a reference to psci_system_reset that – as far as I could tell – no longer existed in the U-Boot code tree, I successfully compiled u-boot.bin, and – together with the sd_fuse Hardkernel binary content – installed it on the C2.

I tried to start the device, but got a constant stream of resets:

Board ID = 8
set vcck to 1100 mv
set vddee to 1050 mv
CPU clk: 1536MHz
DDR channel setting: DDR0 Rank0+1 same
DDR0: 2048MB(auto) @ 912MHz(2T)-13
DataBus test pass!
AddrBus test pass!
Load fip header from eMMC, src: 0x0000c200, des: 0x01400000, size: 0x000000b0
aml log : SIG CHK : 351 for address 0x01700000
reset...
GXBB:BL1:08dafd:0a8993;FEAT:EDFC318C;POC:3;RCY:0;EMMC:0;
 ( line repeated.. )

So… There is ‘mainline’ support for the C2 coming, but not quite there yet..

Robert Gadsdon   April 26, 2016.