Hello.
I have the board with Intel Baytrail E3845 and eMMC card, use coreboot 4.4, seabios 1.9.1, Intel FSP Gold4.
It comes out switch eMMC 4.5 controller to ACPI mode by FSP. If set "Enable PCI mode for SCC devices" (PcdSccEnablePciMode) = Disabled in Binary Configuration Tool (BCT), a controller still a PCI device. Log of FSP DEBUG binary has not changed:
FspNotify(EnumInitPhaseReadyToBoot)
fsp_header_ptr: fffb0094
FSP Header Version: 1
FSP Revision: 3.4
FSP Got Notification. Notification Value : 0x00000040
FSP Ready To Boot ...
Install PPI: 7CE88FB3-4BD7-4679-87A8-A8D8DEE50D2B
Notify: PPI Guid: 7CE88FB3-4BD7-4679-87A8-A8D8DEE50D2B, Peim notify entry point: 7AF9802F
PchInitExitBootCallback() Start
<...>
ConfigureSccAtBoot() Start
Using eMMC 4.5
Overwrite the nslew/pslew -> 0
ConfigureSccAtBoot() End
<...>
PchInitExitBootCallback() End
This choice differs from set "Enable PCI Mode for LPSS SIO devices" = Disabled, which the actual switch LPSS to ACPI mode, with reaction in log:
FspNotify(EnumInitPhaseReadyToBoot)
fsp_header_ptr: fffb0094
FSP Header Version: 1
FSP Revision: 3.4
FSP Got Notification. Notification Value : 0x00000040
FSP Ready To Boot ...
Install PPI: 7CE88FB3-4BD7-4679-87A8-A8D8DEE50D2B
Notify: PPI Guid: 7CE88FB3-4BD7-4679-87A8-A8D8DEE50D2B, Peim notify entry point: 7AF9802F
PchInitExitBootCallback() Start
<...>
ConfigureLpssAtBoot() Start
Switching LPSS1 DMA into ACPI Mode.
Switching LPSS2 DMA into ACPI Mode.
Switching LPSS2 I2C 0 into ACPI Mode.
Switching LPSS2 I2C 1 into ACPI Mode.
Switching LPSS2 I2C 2 into ACPI Mode.
Switching LPSS2 I2C 3 into ACPI Mode.
Switching LPSS2 I2C 4 into ACPI Mode.
Switching LPSS2 I2C 5 into ACPI Mode.
Switching LPSS2 I2C 6 into ACPI Mode.
Switching LPSS1 PWM 0 into ACPI Mode.
Switching LPSS1 PWM 1 into ACPI Mode.
Switching LPSS1 HS-UART 0 into ACPI Mode.
Switching LPSS1 HS-UART 1 into ACPI Mode.
Switching LPSS1 SPI into ACPI Mode.
ConfigureLpssAtBoot() End
<...>
PchInitExitBootCallback() End
Before posting, I also tried enable SD/SDIO/EMMC 4.41 controllers, disable eMMC 4.5, and had seen in log:
ConfigureSccAtBoot() Start
Using eMMC 4.41
Switching SCC SDIO into ACPI Mode.
Switching SCC SD Card into ACPI Mode.
ConfigureSccAtBoot() End
But, eMMC still as PCI device.
P.S. Excuse me for "my english".