Hi, Liming: I found two smbuslib implemented in below path: 1. edk2-platforms\Silicon\Intel\QuarkSocPkg\QuarkNorthCluster\Library\SmbusLib I named this smbuslib as quark-smbuslib 2. MdePkg\Library\PeiSmbusLibSmbus2Ppi\ I name this smbuslib as Mde-smbuslib My questions are: 1. Quark-smbuslib provided some basic smbus operation functions, and these functions could be called by some PEIMs/Dxe drivers So, it means not needed to implement gEfiPeiSmbus2Ppi for PEI phase? (because quark-smbuslib has provided needed functions) 2. Mde-smbuslib will consume gEfiPeiSmbus2PpiGuid This smbuslib is independent , and just uses gEfiPeiSmbus2Ppi to encapsulate some functions. So, a BIOS provider should implement a gEfiPeiSmbus2Ppi for PEI phase? Thanks 发件人: Gao, Liming 发送时间: 2019年11月4日 11:31 收件人: devel@edk2.groups.io; Tiger Liu(BJ-RD) 主题: RE: [edk2-devel] [edk2] Smbuslib and SmbusPpi SmbusPpi is defined in PI spec. SmbusLib is defined in Edk2 MdePkg. Edk2 PEIM can base on SmBusLib. SmBusLib implementation wraps SmBusPpi. Thanks Liming From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of Tiger Liu(BJ-RD) Sent: Thursday, October 31, 2019 6:51 PM To: devel@edk2.groups.io; Gao, Liming > Subject: [edk2-devel] [edk2] Smbuslib and SmbusPpi Hi, Liming: I have a question about smbus access during pei phase. I found there was not smbus ppi reference implementation in edk2-platform code base. And there was a SmbusLib reference implementation lib. So, PEIMs usually use functions provided by SmbusLib? Not use PeiSmbusPpi’s interface functions? Thanks Best wishes, 保密声明: 本邮件含有保密或专有信息,仅供指定收件人使用。严禁对本邮件或其内容做任何未经授权的查阅、使用、复制或转发。 CONFIDENTIAL NOTE: This email contains confidential or legally privileged information and is for the sole use of its intended recipient. Any unauthorized review, use, copying or forwarding of this email or the content of this email is strictly prohibited. 保密声明: 本邮件含有保密或专有信息,仅供指定收件人使用。严禁对本邮件或其内容做任何未经授权的查阅、使用、复制或转发。 CONFIDENTIAL NOTE: This email contains confidential or legally privileged information and is for the sole use of its intended recipient. Any unauthorized review, use, copying or forwarding of this email or the content of this email is strictly prohibited.