On Thu, Sep 7, 2017 at 1:40 PM, Nico Huber nico.h@gmx.de wrote:
Hello Alberto,
On 09/06/2017 09:30 PM, Alberto Bursi wrote:
I've stumbled upon a Asrock IMB-A180-H board (a eKabini-based "industrial" mini-itx motherboard) on ebay and since it is supported by Coreboot I was considering about purchasing it.
The APU onboard supports ECC ram (ECC so-dimms are kinda rare but I can find them), while of course the Asrock site does not say anything about ECC support (how unexpected).
it's rather unlikely that a board supports it when the manufacturer doesn't mention it. ECC support needs additional traces on the main- board (as the bus is 72 bits wide instead of 64 bits). So just having compatible chips doesn't suffice.
See JEDEC Module 4.20.18 vs 4.20.21 standards.
SODIMM 204-pin socket pinout for 64bit non-ECC vs 72bit ECC is already different. Some ground pins have been sacrificed to fit those extra ECC bits in the socket. In other words: no amount of open source will give you ECC SO-DIMM support when PCB was designed otherwise.
That board is one of eKabini reference desings, schematics check tells me ECC pins of the APU SOC part are not connected.
Kyösti