DISCONTINUATION OF PROJECT

This project will no longer be maintained by Intel.
Intel has ceased development and contributions including, but not limited to, maintenance, bug fixes, new releases, or updates, to this project.
Intel no longer accepts patches to this project.
If you have an ongoing need to use this project, are interested in independently developing it, or would like to maintain patches for the open source software community, please create your own fork of this project.

Host miscellaneous communication manager

This component is intended to expose certain miscellaneous host interface communication mechanisms like PLTRST, Core BIOS Done & MailBox registers.

Overview

In OpenBMC, miscellaneous host interface communications like PLTRST, Core BIOS Done, & MailBox registers must be used by different applications. As OpenBMC relies on D-Bus, the same needs to be exposed in D-Bus, so that single application can monitor it from driver end, and propagate details to many applications.

Capabilities

host-misc-comm-manager will monitor the PLTRST, Core BIOS Done, & MailBox registers from it's corresponding driver and expose the same in it's own D-Bus object & properties.

Following objects with interface & properties mentioned below will be exposed

1. Object under /xyz/openbmc_project/misc/platform_state will expose xyz.openbmc_project.State.Host.Misc interface with 2 boolean type read-only propertiesESpiPlatformReset & CoreBiosDone.

2. Object under /xyz/openbmc_project/misc/mailbox/<register> will expose xyz.openbmc_project.Misc.Mailbox interface and under which uint8_t value of property named Value will be exposed. There will be n number of similar objects based on the mailbox size. Application can update the register value by modifying Value property.

eSPI platform reset

eSPI platform reset can be used to determine the host reset.

Core BIOS Done

Used to indicate that UEFI has finished executing Core DXE Phase, and started dispatching external OpROM code. Any security feature like KCS Trust policy enforcement must be enabled at this point of time.

Note: For enhanced security 600 seconds timeout is implemented, beyond which BMC will assume that BIOS has finished Core DXE Phase.

UEFI & BMC can use any agreed method to indicate CoreBiosDone as long as external OpROM can not revert, before BMC detects it. Products with AST2500 / AST2600 BMC chip must use the SIO software interrupt register, which provides a way for BMC to detect that UEFI has set this bit already, even if external OpROM tries to clear the same. This interrupt bit can not be cleared from UEFI end and can only be cleared from BMC end. The register location differs between AST2500 and AST2600, so UEFI firmware for supported products must use the correct one to indicate CoreBiosDone:

• AST2500: SIORx_20[0]
• AST2600: SIORx_21[0]

Mailbox registers

Mailbox registers under AST2500 / AST2600, will be exposed as D-Bus objects. These registers are used for communication with Host & BMC. Individual register usage is beyond the scope of this component.