[coreboot] [baytrail_FSP] question about lpss device with ACPI mode in win8

Zoran Stojsavljevic zoran.stojsavljevic at gmail.com
Tue May 17 05:36:24 CEST 2016

Hello Cheng,

I am afraid, I have no ideas anymore what could be wrong. But I have for
you one suggestion (path to resolution, maybe).

No idea what you are using. In the sense BYT-FSP (MR5) -> Coreboot ->
(payload???). You either use SeaBIOS (CSM ON), or Tiano Core/EK2 (CSM OFF).

I would suggest the following: since it depends what payload you use
because you would like to reuse your old HDD with WIN 8.1, to make test
very short (no need to install other HDD with WIN 8.1).

Please, take real UEFI BIOS (for BYT-M N2807 it is Client Group 64bit
A093.R42 or later), and install it on some INTEL CRB (BayleyBay or
BakerSport) where you already have N2807. Then, in relations what payload
you are using, you need to set CSM ON or CSM OFF, to make work/reuse your
original HDD with WIN 8.1.

Please, after you are able to bring your INTEL BYT-M CRB to WIN 8.1,
reboot, and again enter BIOS CMOS. There, under system setup/advanced
settings, you should be able to find southbridge setup, where one of the
options is LPSS.

Please, experiment, with settings within LPSS mode (PCI and ACPI), and,
please, report here do you have the same as with BYT-FSP MR5 settings as
you use "pcdlpsssioenablepcimode" to "LPSS_PCI_MODE_DISABLE" and
"ENABLE/DEFAULT" (do you see the same behavior in WIN 8.1 device manager)?

Thank you,

On Mon, May 16, 2016 at 2:06 PM, cheng yichen <blessyichen at gmail.com> wrote:

> Hi  Zoran
> Base on the version Baytrail_coreboot_MR5_Dec-21-2015(coreboot) that is
> released by Intel.
> In the coreboot(Intel released and defautle is acpi mode) I can install
> driver and device is workable in win8.
> I can see hs-uart controller in device manage and no yellow mark.
> In last coreboot source code. after I modify "pcdlpsssioenablepcimode" to
> "LPSS_PCI_MODE_DISABLE". Then the lpss device will be confgured to ACPI
> mode.
> but the hs-uart controller and I2C controller will shown yellow mark in
> win8 device manager.
> Because the main controller is not workable in win8. I don't check the
> sub-device device.
> 2016-05-16 17:16 GMT+08:00 Zoran Stojsavljevic <
> zoran.stojsavljevic at gmail.com>:
>> Hello Cheng,
>> Again, I'll repeat my questions:
>> [1] Are you talking about BIOS, where you are enabling in LPSS ACPI
>> (disabling automatically PCI) mode?
>> [2] I need better explanation of your use case... Are you using BYT MR4,
>> then MR5, or instead MR4 BIOS, or...?
>> [3] For WIN8.1 you need to have the following:
>>       For BIOS to work (and get rid off these yellow triangles with
>> question marks):
>>       [A] ACPI mode in BIOS: South Cluster Configuration -> LPSS & SCC
>> Configuration -> LPSS LPSS & SCC
>>            Devices Mode -> Select "ACPI Mode";
>>       [B] The GPIO controller driver is/should be prerequisite for
>> HS-UART driver. There is a document named:
>>             Intel_Processor_Win8_IO_Drivers_Gold_MR1. You should ask for
>> it from INTEL support. If installed
>>             correctly, you should see HS-UART Controller device under
>> System Devices in Device Manager. Also
>>             new unknown devices should appear: ACPI\BCM2E1A and
>> ACPI\BCM4752. These devices are for
>>             HS-UART Sub Device Driver;
>>       [C] You should compile the UART Sub Device Driver (by 1.2.1 of
>> Intel Atom E3800 Win8.1 HS-UART Sub
>>             Device Driver Sample Code Guide_1.0), and install after
>> building them. After that you should see Ports in
>>             Device Manager.
>> Zoran
>> On Fri, May 13, 2016 at 5:43 AM, cheng yichen <blessyichen at gmail.com>
>> wrote:
>>> HI all
>>> I try to enable Lpss device(i2c hs-uart) with ACPI mdoe.
>>> i2c and hs-uart will show yellow mark in device manager with win8.1.
>>> but I can't find the same issue in intel coreboot(versrion MR5).
>>> Do you have any idea for the issue? Thank you
>>> --
>>> coreboot mailing list: coreboot at coreboot.org
>>> https://www.coreboot.org/mailman/listinfo/coreboot
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