# UEFI Redfish EDK2 Implementation

## Introduction
UEFI Redfish EDK2 solution is an efficient and secure solution for the end-users to remote configure (in Out-of-band) UEFI platform configurations by leveraging the Redfish RESTful API.  It's simple for end-users to access the configurations of UEFI firmware which have the equivalent properties defined in Redfish schema.

Below are the block diagrams of UEFI Redfish EDK2 Implementation. ***[EDK2 Redfish Foundation[1]](#[0])*** in the lower part of the figure refers to the EDK2 Redfish Foundation, which provides the fundamental EDK2 drivers to communicate with Redfish service ***([[19]](#[0]) in the above figure)***. The Redfish service could be implemented in BMC to manage the system, or on the network for managing multiple systems.

***[EDK2 Redfish Client[2]](#[0])*** in the upper part of the figure refers to the EDK2 Redfish client, which is the EDK2 Redfish application used to configure platform configurations by consuming the Redfish properties. The EDK2 Redfish client can also provision the UEFI platform-owned Redfish properties, consume and update Redfish properties as well. The ***[EDK2 Redfish Feature DXE Drivers [17]](#[0])*** is the next project after EDK2 Redfish Foundation. Each EDK2 Redfish Feature DXE Driver is designed to communicate with the particular Redfish data model defined in the Redfish schema *(e.g. Edk2RedfishBiosDxe driver manipulates the properties defined in Redfish BIOS data model)*.

## <a name="[0]">EDK2 Redfish Implementation Diagrams</a>
![UEFI Redfish Implementation](https://github.com/tianocore/edk2/blob/master/RedfishPkg/Documents/Media/RedfishDriverStack.svg?raw=true)

## EFI EDK2 Redfish Driver Stack
Below are the EDK2 drivers implemented on EDK2,

### EDK2 Redfish Host Interface DXE Driver ***[[6]](#[0])***

The abstract EDK2 DXE driver to create SMBIOS type 42 record through EFI SMBIOS protocol according to the device descriptor and protocol type data (defined in SMBIOS type 42h ***[[7]](#[0])***) provided by platform level Redfish host interface library. On EDK2 open source implementation (**EmulatorPkg**), SMBIOS type 42 data is retrieved from EFI variables created by RedfishPlatformConfig.efi ***[[20]](#[0])*** under EFI shell. OEM may provide its own PlatformHostInterfaceLib ***[[11]](#[0])*** instance for the platform-specific implementation.

### EDK2 Refish Credential DXE Driver ***[[5]](#[0])***

The abstract DXE driver which incorporates with RedfishPlatformCredentialLib ***[[10]](#[0])*** to acquire the credential of Redfish service. On edk2 EmulatorPkg implementation, the credential is hardcoded using the fixed Account/Password in order to connect to Redfish service established by [Redfish Profile Simulator](https://github.com/DMTF/Redfish-Profile-Simulator). OEM may provide its own RedfishPlatformCredentialLib instance for the platform-specific implementation.

### EFI REST EX UEFI Driver for Redfish service ***[[4]](#[0])***

This is the network-based driver instance of EFI_REST_EX protocol [(UEFI spec 2.8, section 29.7.2)](http://uefi.org/specifications) for communicating with Redfish service using the HTTP protocol. OEM may have its own EFI REST EX UEFI Driver instance on which the underlying transport to Redfish service could be proprietary.

### EFI Redfish Discover UEFI Driver  ***[[3]](#[0])***

EFI Redfish Discover Protocol implementation (UEFI spec 2.8, section 31.1). Only support Redfish service discovery through Redfish Host Interface. The Redfish service discovery using SSDP over UDP ***[[18]](#[0])*** is not implemented at the moment.

### EFI REST JSON Structure DXE Driver  ***[[9]](#[0])***

EFI REST JSON Structure DXE implementation (UEFI spec 2.8, section 29.7.3). This could be used by EDK2 Redfish Feature DXE Drivers ***[[17]](#[0])***. The EDK2 Redfish feature drivers manipulate platform-owned Redfish properties in C structure format and convert them into the payload in JSON format through this protocol. This driver leverages the effort of [Redfish Schema to C Generator](https://github.com/DMTF/Redfish-Schema-C-Struct-Generator) to have the "C Structure" <-> "JSON" conversion.

### EDK2 Redfish Config Handler UEFI Driver ***[[15]](#[0])***

This is the centralized manager of EDK2 Redfish feature drivers, it initiates EDK2 Redfish feature drivers by invoking init() function of EDK2 Redfish Config Handler Protocol ***[[16]](#[0])*** installed by each EDK2 Redfish feature driver. EDK2 Redfish Config Handler driver is an UEFI driver which has the dependency with EFI REST EX protocol and utilizes EFI Redfish Discover protocol to discover Redfish service that manages this system.

### EDK2 Content Coding Library ***[[12]](#[0])***
The library is incorporated with RedfishLib ***[[13]](#[0])*** to encode and decode Redfish JSON payload. This is the platform library to support HTTP Content-Encoding/Accept-Encoding headers. EumlatorPkg use the NULL instance of this library because [Redfish Profile Simulator](https://github.com/DMTF/Redfish-Profile-Simulator) supports neither HTTP Content-Encoding header on the payload returned to Redfish client nor HTTP Accept-Encoding header.

## Other Open Source Projects
  The following libraries are the wrappers of other open source projects used in RedfishPkg

  * **RedfishPkg\PrivateLibrary\RedfishLib**  ***[[13]](#[0])***
  This is the wrapper of open source project ***[libredfish](https://github.com/DMTF/libredfish)***,
  which is the library to initialize the connection to Redfish service with the proper credential and execute Create/Read/Update/Delete (CRUD) HTTP methods on Redfish properties.

  * **RedfishPkg\Library\JsonLib** ***[[14]](#[0])***
  This is the wrapper of open source project ***[Jansson](https://digip.org/jansson)***,  which is the library that provides APIs to manipulate JSON payload.

## Platform Components for EDK2 EmulatorPkg:
  * **RedfishPlatformCredentialLib**
  the EDK2 Emulator platform implementation of acquiring credential to build up the communication between UEFI firmware and Redfish service. ***[[10]](#[0])***

  * **RedfishPlatformHostInterfaceLib**
  EDK2 Emulator platform implementation which provides the information of building up SMBIOS type 42h record. ***[[11]](#[0])***

## Miscellaneous:

   * **EFI Shell Application**
   RedfishPlatformConfig.exe is an EFI Shell application used to set up the Redfish service information for the EDK2 Emulator platform. The information such as IP address, subnet, and port.
   ```C
    For example, run shell command "RedfishPlatformConfig.efi -s 192.168.10.101 255.255.255.0 192.168.10.123 255.255.255.0", which means
      the source IP address is 192.168.10.101, and the Redfish Server IP address is 192.168.10.123.
   ```

   * **Redfish Profile Simulator**
   Refer to [Redfish Profile Simulator](https://github.com/DMTF/Redfish-Profile-Simulator) to set up the Redfish service.
   We are also in the progress to contribute bug fixes and enhancements to the mainstream Redfish Profile Simulator in order to incorporate with EDK2 Redfish solution.

## Connect to Redfish Service on EDK2 Emulator Platform
   1. Install the WinpCap and copy [SnpNt32Io.dll](https://github.com/tianocore/edk2-NetNt32Io) to the building directory of the Emulator platform. This is the emulated network interface for EDK2 Emulator Platform.
   ```C
   e.g. %WORKSPACE%/Build/EmulatorX64/DEBUG_VS2015x86/X64
   ```

   2. Enable below macros in EmulatorPkg.dsc
   ```C
  NETWORK_HTTP_ENABLE = TRUE
  SECURE_BOOT_ENABLE = TRUE
  REDFISH_ENABLE = TRUE
   ```

   3. Allow HTTP connection
   Enable below macro to allow HTTP connection on EDK2 network stack for connecting to [Redfish Profile Simulator](https://github.com/DMTF/Redfish-Profile-Simulator) becasue Redfish Profile Simulator doesn't support HTTPS.
   ```C
   NETWORK_ALLOW_HTTP_CONNECTIONS = TRUE
   ```

   4. Assign the correct MAC Address
   Assign the correct MAC address of the network interface card emulated by WinpCap.
   - Rebuild EmulatorPkg and boot to EFI shell once SnpNt32Io.dll is copied to the building directory and the macros mentioned in #2 are all set to TURE.
   - Execute the EFI shell command "ifconfig -l" under EFI shell and look for MAC address information, then assign the MAC address to below PCD.
   ```c
   gEfiRedfishPkgTokenSpaceGuid.PcdRedfishRestExServiceDevicePath.DevicePath|{DEVICE_PATH("MAC(000000000000,0x1)")}
   ```

   5. Configure the Redfish service on the EDK2 Emulator platform

   Execute RedfishPlatformConfig.efi under EFI shell to configure the Redfish service information. The EFI variables are created for storing Redfish service information and is  consumed by RedfishPlatformHostInterfaceLib under EmulatorPkg.

## Related Materials
1. [DSP0270](https://www.dmtf.org/sites/default/files/standards/documents/DSP0270_1.3.0.pdf) - Redfish Host Interface Specification, 1.3.0
2. [DSP0266](https://www.dmtf.org/sites/default/files/standards/documents/DSP0266_1.12.0.pdf) - Redfish Specification, 1.12.0
3. Redfish Schemas - https://redfish.dmtf.org/schemas/v1/
4. UEFI Specification - http://uefi.org/specifications

## The Contributors
Thanks to the below predecessors who contributed to the UEFI EDK2 Redfish Prove of Concept code.\
Fu, Siyuan <siyuan.fu@intel.com>\
Ye, Ting <ting.ye@intel.com>\
Wang, Fan <fan.wang@intel.com>\
Wu, Jiaxin <jiaxin.wu@intel.com>\
Yao, Jiewen <jiewen.yao@intel.com>\
Shia, Cinnamon <cinnamon.shia@hpe.com>
