mirror of https://github.com/acidanthera/audk.git
3 Commits
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Nicolas Ojeda Leon
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a1bd79c514 |
Ovmf/HardwareInfoLib: Add Dxe lib to dynamically parse heterogenous data
Following the Hardware Info library, create the DxeHardwareInfoLib which implements the whole API capable of parsing heterogeneous hardware information. The list-like API grants callers a flexible and common pattern to retrieve the data. Moreover, the initial source is a BLOB which generalizes the host-to-guest transmission mechanism. The Hardware Info library main objective is to provide a way to describe non-discoverable hardware so that the host can share the available resources with the guest in Ovmf platforms. This change features and embraces the main idea behind the library by providing an API that parses a BLOB into a linked list to retrieve hardware data from any source. Additionally, list-like APIs are provided so that the hardware info list can be traversed conveniently. Similarly, the capability is provided to filter results by specific hardware types. However, heterogeneous elements can be added to the list, increasing the flexibility. This way, a single source, for example a fw-cfg file, can be used to describe several instances of multiple types of hardware. This part of the Hardware Info library makes use of dynamic memory and is intended for stages in which memory services are available. A motivation example is the PciHostBridgeLib. This library, part of the PCI driver populates the list of PCI root bridges during DXE stage for future steps to discover the resources under them. The hardware info library can be used to obtain the detailed description of available host bridges, for instance in the form of a fw-cfg file, and parse that information into a dynmaic list that allows, first to verify consistency of the data, and second discover the resources availabe for each root bridge. Cc: Alexander Graf <graf@amazon.de> Cc: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com> |
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Nicolas Ojeda Leon
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2b1a5b8c61 |
Ovmf/HardwareInfoLib: Create Pei lib to parse directly from fw-cfg
Define the HardwareInfoLib API and create the PeiHardwareInfoLib which implements it, specifically for Pei usage, supporting only static accesses to parse data directly from a fw-cfg file. All list-like APIs are implemented as unsupported and only a fw-cfg wrapper to read hardware info elements is provided. The Hardware Info library is intended to describe non-discoverable hardware information and share that from the host to the guest in Ovmf platforms. The QEMU fw-cfg extension for this library provides a first variation to parse hardware info by reading it directly from a fw-cfg file. This library offers a wrapper function to the plain QmeuFwCfgReadBytes which, specifically, parses header-data pairs out of the binary values in the file. For this purpose, the approach is incremental, reading the file block by block and outputting the values only for a specific known hardware type (e.g. PCI host bridges). One element is returned in each call until the end of the file is reached. Considering fw-cfg as the first means to transport hardware info from the host to the guest, this wrapping library offers the possibility to statically, and in steps, read a specific type of hardware info elements out of the file. This method reads one hardware element of a specific type at a time, without the need to pre-allocate memory and read the whole file or dynamically allocate memory for each new element found. As a usage example, the static approach followed by this library enables early UEFI stages to use and read hardware information supplied by the host. For instance, in early times of the PEI stage, hardware information can be parsed out from a fw-cfg file prescinding from memory services, that may not yet be available, and avoiding dynamic memory allocations. Cc: Alexander Graf <graf@amazon.de> Cc: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com> |
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Nicolas Ojeda Leon
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6c9f218bc0 |
OvmfPkg/Library: Create base HardwareInfoLib for PCI Host Bridges
Create the Hardware Info library base together with the specifics to describe PCI Host Bridges. The Hardware Info library is intended to be used for disclosing non-discoverable hardware information from the host to the guest in Ovmf platforms. Core functionality will provide the possibility to parse information from a generic BLOB into runtime structures. The library is conceived in a generic way so that further hardware elements can also be described using it. For such purpose the length of the BLOB is not restricted but instead regarded as a sequence of header-info elements that allow the parsing during runtime. The first type of hardware defined will be PCI host bridges, providing the possibility to define multiple and specify the resources each of them can use. This enables the guest firmware to configure PCI resources properly. Having the size of each individual element favors the reuse of a single interface to convey descriptions of an arbitrary number of heterogenous hardware elements. Furthermore, flexible access mechanisms coupled with the size will grant the possibility of interpreting them in a single run. Define the base types of the generic Hardware Info library to parse heterogeneous data. Also provide the specific changes to support PCI host bridges as the first hardware type supported by the library. Additionally, define the HOST_BRIDGE_INFO structure to describe PCI host bridges along with the functionality to parse such information into proper structures used by the PCI driver in a centralized manner and taking care of versioning. As an example and motivation, the library will be used to define multiple PCI host bridges for complex platforms that require it. The first means of transportation that will be used is going to be fw-cfg, over which a stream of bytes will be transferred and later parsed by the hardware info library. Accordingly, the PCI driver will make use of these host bridges definitions to populate the list of Root Bridges and proceed with the configuration and discovery of underlying hardware components. As mentioned before, the binary data to be parsed by the Hardware Info library should be organized as a sequence of Header-element pairs in which the header describes the type and size of the associated element that comes right after it. As an illustration, to provide inforation of 3 host bridges the data, conceptually, would look like this: Header PCI Host Bridge (type and size) # 1 PCI Host Bridge info # 1 Header PCI Host Bridge (type and size) # 2 PCI Host Bridge info # 2 Header PCI Host Bridge (type and size) # 3 PCI Host Bridge info # 3 Cc: Alexander Graf <graf@amazon.de> Cc: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com> |