OvmfPkg/Include/IndustryStandard/QemuLoader.h

   1 /** @file
   2   Command structures for the QEMU FwCfg table loader interface.
   3
   4   Copyright (C) 2014, Red Hat, Inc.
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #ifndef QEMU_LOADER_H_
  11 #define QEMU_LOADER_H_
  12
  13 #include <Base.h>
  14 #include <IndustryStandard/QemuFwCfg.h>
  15
  16 //
  17 // The types and the documentation reflects the SeaBIOS interface.
  18 //
  19 #define QEMU_LOADER_FNAME_SIZE  QEMU_FW_CFG_FNAME_SIZE
  20
  21 typedef enum {
  22   QemuLoaderCmdAllocate = 1,
  23   QemuLoaderCmdAddPointer,
  24   QemuLoaderCmdAddChecksum,
  25   QemuLoaderCmdWritePointer,
  26 } QEMU_LOADER_COMMAND_TYPE;
  27
  28 typedef enum {
  29   QemuLoaderAllocHigh = 1,
  30   QemuLoaderAllocFSeg
  31 } QEMU_LOADER_ALLOC_ZONE;
  32
  33 #pragma pack (1)
  34 //
  35 // QemuLoaderCmdAllocate: download the fw_cfg file named File, to a buffer
  36 // allocated in the zone specified by Zone, aligned at a multiple of Alignment.
  37 //
  38 typedef struct {
  39   UINT8     File[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
  40   UINT32    Alignment;                    // power of two
  41   UINT8     Zone;                         // QEMU_LOADER_ALLOC_ZONE values
  42 } QEMU_LOADER_ALLOCATE;
  43
  44 //
  45 // QemuLoaderCmdAddPointer: the bytes at
  46 // [PointerOffset..PointerOffset+PointerSize) in the file PointerFile contain a
  47 // relative pointer (an offset) into PointeeFile. Increment the relative
  48 // pointer's value by the base address of where PointeeFile's contents have
  49 // been placed (when QemuLoaderCmdAllocate has been executed for PointeeFile).
  50 //
  51 typedef struct {
  52   UINT8     PointerFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
  53   UINT8     PointeeFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
  54   UINT32    PointerOffset;
  55   UINT8     PointerSize;                      // one of 1, 2, 4, 8
  56 } QEMU_LOADER_ADD_POINTER;
  57
  58 //
  59 // QemuLoaderCmdAddChecksum: calculate the UINT8 checksum (as per
  60 // CalculateChecksum8()) of the range [Start..Start+Length) in File. Store the
  61 // UINT8 result at ResultOffset in the same File.
  62 //
  63 typedef struct {
  64   UINT8     File[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
  65   UINT32    ResultOffset;
  66   UINT32    Start;
  67   UINT32    Length;
  68 } QEMU_LOADER_ADD_CHECKSUM;
  69
  70 //
  71 // QemuLoaderCmdWritePointer: the bytes at
  72 // [PointerOffset..PointerOffset+PointerSize) in the writeable fw_cfg file
  73 // PointerFile are to receive the absolute address of PointeeFile, as allocated
  74 // and downloaded by the firmware, incremented by the value of PointeeOffset.
  75 // Store the sum of (a) the base address of where PointeeFile's contents have
  76 // been placed (when QemuLoaderCmdAllocate has been executed for PointeeFile)
  77 // and (b) PointeeOffset, to this portion of PointerFile.
  78 //
  79 // This command is similar to QemuLoaderCmdAddPointer; the difference is that
  80 // the "pointer to patch" does not exist in guest-physical address space, only
  81 // in "fw_cfg file space". In addition, the "pointer to patch" is not
  82 // initialized by QEMU in-place with a possibly nonzero offset value: the
  83 // relative offset into PointeeFile comes from the explicit PointeeOffset
  84 // field.
  85 //
  86 typedef struct {
  87   UINT8     PointerFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
  88   UINT8     PointeeFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
  89   UINT32    PointerOffset;
  90   UINT32    PointeeOffset;
  91   UINT8     PointerSize;                      // one of 1, 2, 4, 8
  92 } QEMU_LOADER_WRITE_POINTER;
  93
  94 typedef struct {
  95   UINT32    Type;                          // QEMU_LOADER_COMMAND_TYPE values
  96   union {
  97     QEMU_LOADER_ALLOCATE         Allocate;
  98     QEMU_LOADER_ADD_POINTER      AddPointer;
  99     QEMU_LOADER_ADD_CHECKSUM     AddChecksum;
 100     QEMU_LOADER_WRITE_POINTER    WritePointer;
 101     UINT8                        Padding[124];
 102   } Command;
 103 } QEMU_LOADER_ENTRY;
 104 #pragma pack ()
 105
 106 #endif