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eMMC in ACPI mode on Baytrail E3845

NNo1
Beginner
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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".

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CarlosAM_INTEL
Moderator
1,981 Views

Hello ustas,

Thank you for contacting Intel Embedded Community.

There are actually three UARTS on the Bay Trail SoC – two HSUARTs that are part of the Serial IO (SIO) block of devices, and one legacy UART, that is part of the Platform Controller Unit (PCU) block of devices.

The HSUART registers are accessed through PCI BARs, whereas the legacy UART uses the legacy COM1 I/O space registers, 3f8h-3ffh.

Whether or not they disable the on-chip HSUARTs is irrelevant, as they don't use the legacy I/O space addresses for COM1 and COM2.

Although you can disable the HSUARTs with the BCT, the legacy UART cannot be enabled or disabled via the BCT. The legacy UART is actually enabled in coreboot - file coreboot/src/soc/intel/fsp_baytrail/romstage/romstage.c calls function byt_config_com1_and_enable(), which is implemented in file coreboot/src/soc/intel/fsp_baytrail/romstage/uart.c and sets the bit to enable the legacy UART (it's disabled by default when the chip powers on). This could be replaced by code that initializes COM1 on the Fintek part instead of the UART.

Note that the FSP might also enable the legacy UART internally during the call to FspInitEntry. If so, then it would simply need to be disabled again in the continuation function, which, in coreboot, is function romstage_main_continue() located in file coreboot/src/soc/intel/fsp_baytrail/romstage/romstage.c.

Here is the public datasheet for reference on the various UARTs:

http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-e3800-family-datasheet.pdf http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-e3800-family-datasheet.pdf

Also, you can review as a reference the http://coreboot.coreboot.narkive.com/NhtYEW1e/baytrail-mmc-acpi-mode Baytrail MMC ACPI mode and https://www.coreboot.org/pipermail/seabios/2016-January/010300.html Does SeaBIOS support eMMC? forums that may have some information that can help you.

Please let us know if this information is useful to you.

Best Regards,

Carlos_A.

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NNo1
Beginner
1,981 Views

Hello, Carlos.

I read this before create theme.

Essence of problem - Intel FSP does not switch eMMC controller to ACPI mode. It seems to me, cause in it, within. Could you please check this on your side?

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CarlosAM_INTEL
Moderator
1,981 Views

Hello ustas,

Thanks for your reply.

We suggest you address this consultation to the channels listed as a reference at the https://www.seabios.org/mailman/listinfo/seabios SeaBIOS mailing list .

We hope that this information may help you.

Best Regards,

Carlos_A.

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NNo1
Beginner
1,981 Views

What relation does the problem have to SeaBIOS, if switch to ACPI mode is FSP function?

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CarlosAM_INTEL
Moderator
1,981 Views

Hello ustas,

Thanks for your reply.

Our suggestion is based on the fact that you are using the cited kind of software. So, it is possible that its developer may have some information that could help you to solve this problem.Feel free to contact them.

We hope that this clarification may help you to understand our recommendation.

Best Regards,

Carlos_A.

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