EmbeddedPkg/Library/FdtLib/FdtConfigurationTable.c

   1 /** @file
   2 *
   3 *  Copyright (c) 2014, ARM Limited. All rights reserved.
   4 *
   5 *  This program and the accompanying materials
   6 *  are licensed and made available under the terms and conditions of the BSD License
   7 *  which accompanies this distribution.  The full text of the license may be found at
   8 *  http://opensource.org/licenses/bsd-license.php
   9 *
  10 *  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 *  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 *
  13 **/
  14
  15 #include <Uefi.h>
  16 #include <Library/DebugLib.h>
  17 #include <Library/MemoryAllocationLib.h>
  18 #include <Library/UefiBootServicesTableLib.h>
  19
  20 #include <Protocol/DevicePath.h>
  21 #include <Protocol/SimpleFileSystem.h>
  22
  23 #include <Guid/Fdt.h>
  24 #include <Guid/FileInfo.h>
  25
  26 #include <libfdt.h>
  27
  28 //
  29 // Device path for SemiHosting
  30 //
  31 STATIC CONST struct {
  32   VENDOR_DEVICE_PATH        Guid;
  33   EFI_DEVICE_PATH_PROTOCOL  End;
  34 } mSemihostingDevicePath = {
  35   {
  36     { HARDWARE_DEVICE_PATH, HW_VENDOR_DP, { sizeof (VENDOR_DEVICE_PATH), 0 } },
  37     { 0xC5B9C74A, 0x6D72, 0x4719, { 0x99, 0xAB, 0xC5, 0x9F, 0x19, 0x90, 0x91, 0xEB } }
  38   },
  39   { END_DEVICE_PATH_TYPE, END_ENTIRE_DEVICE_PATH_SUBTYPE, { sizeof (EFI_DEVICE_PATH_PROTOCOL), 0 } }
  40 };
  41
  42
  43 /**
  44   This function declares the passed FDT into the UEFI Configuration Table
  45
  46   @param FdtBlob    Base address of the Fdt Blob in System Memory
  47   @param FdtSize    Size of the Fdt Blob in System Memory
  48
  49   @return EFI_SUCCESS           Fdt Blob was successfully installed into the configuration table
  50   @return !EFI_SUCCESS          Error returned by BS.InstallConfigurationTable()
  51
  52 **/
  53 STATIC
  54 EFI_STATUS
  55 InstallFdtIntoConfigurationTable (
  56   IN VOID* FdtBlob,
  57   IN UINTN FdtSize
  58   )
  59 {
  60   EFI_STATUS Status;
  61
  62   // Check the FDT header is valid. We only make this check in DEBUG mode in case the FDT header change on
  63   // production device and this ASSERT() becomes not valid.
  64   ASSERT (fdt_check_header (FdtBlob) == 0);
  65
  66   // Ensure the Size of the Device Tree is smaller than the size of the read file
  67   ASSERT ((UINTN)fdt_totalsize (FdtBlob) <= FdtSize);
  68
  69   // Install the FDT into the Configuration Table
  70   Status = gBS->InstallConfigurationTable (&gFdtTableGuid, FdtBlob);
  71
  72   return Status;
  73 }
  74
  75
  76 /**
  77   Load and Install FDT from Semihosting
  78
  79   @param Filename   Name of the file to load from semihosting
  80
  81   @return EFI_SUCCESS           Fdt Blob was successfully installed into the configuration table
  82                                 from semihosting
  83   @return EFI_NOT_FOUND         Fail to locate the file in semihosting
  84   @return EFI_OUT_OF_RESOURCES  Fail to allocate memory to contain the blob
  85 **/
  86 EFI_STATUS
  87 InstallFdtFromSemihosting (
  88   IN  CONST CHAR16*   FileName
  89   )
  90 {
  91   EFI_STATUS                       Status;
  92   EFI_DEVICE_PATH*                 Remaining;
  93   EFI_HANDLE                       Handle;
  94   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *SemihostingFs;
  95   EFI_FILE_PROTOCOL               *Fs;
  96   EFI_FILE_PROTOCOL               *File;
  97   EFI_PHYSICAL_ADDRESS             FdtBase;
  98   EFI_FILE_INFO                   *FileInfo;
  99   UINTN                            FdtSize;
 100   UINTN                            FileInfoSize;
 101
 102   // Ensure the Semihosting driver is initialized
 103   Remaining = (EFI_DEVICE_PATH*)&mSemihostingDevicePath;
 104   // The LocateDevicePath() function locates all devices on DevicePath that support Protocol and returns
 105   // the handle to the device that is closest to DevicePath. On output, the device path pointer is modified
 106   // to point to the remaining part of the device path
 107   Status = gBS->LocateDevicePath (&gEfiDevicePathProtocolGuid, &Remaining, &Handle);
 108   if (EFI_ERROR (Status)) {
 109     ASSERT_EFI_ERROR (Status);
 110     return Status;
 111   }
 112
 113   // Recursive = FALSE: We do not want to start the whole device tree
 114   Status = gBS->ConnectController (Handle, NULL, Remaining, FALSE);
 115   if (EFI_ERROR (Status)) {
 116     return Status;
 117   }
 118
 119   // Locate the FileSystem
 120   Status = gBS->HandleProtocol (Handle, &gEfiSimpleFileSystemProtocolGuid, (VOID **)&SemihostingFs);
 121   if (EFI_ERROR (Status)) {
 122     ASSERT_EFI_ERROR (Status);
 123     return Status;
 124   }
 125
 126   // Try to Open the volume and get root directory
 127   Status = SemihostingFs->OpenVolume (SemihostingFs, &Fs);
 128   if (EFI_ERROR (Status)) {
 129     DEBUG ((EFI_D_WARN, "Warning: Fail to open semihosting filesystem that should contain FDT file.\n"));
 130     return Status;
 131   }
 132
 133   File = NULL;
 134   Status = Fs->Open (Fs, &File, (CHAR16*)FileName, EFI_FILE_MODE_READ, 0);
 135   if (EFI_ERROR (Status)) {
 136     DEBUG ((EFI_D_WARN, "Warning: Fail to load FDT file '%s'.\n", FileName));
 137     Fs->Close (Fs);
 138     return Status;
 139   }
 140
 141   FileInfoSize = 0;
 142   File->GetInfo (File, &gEfiFileInfoGuid, &FileInfoSize, NULL);
 143   FileInfo = AllocatePool (FileInfoSize);
 144   if (FileInfo == NULL) {
 145     Status = EFI_OUT_OF_RESOURCES;
 146     goto CLOSE_FILES;
 147   }
 148   Status = File->GetInfo (File, &gEfiFileInfoGuid, &FileInfoSize, FileInfo);
 149   if (EFI_ERROR (Status)) {
 150     FreePool (FileInfo);
 151     goto CLOSE_FILES;
 152   }
 153
 154   // Get the file size
 155   FdtSize = FileInfo->FileSize;
 156   FreePool (FileInfo);
 157
 158   // The FDT blob is attached to the Configuration Table. It is recommended to load it as Runtime Service Data
 159   // to prevent the kernel to overwrite its data
 160   Status = gBS->AllocatePages (AllocateAnyPages, EfiRuntimeServicesData, EFI_SIZE_TO_PAGES (FdtSize), &FdtBase);
 161   if (!EFI_ERROR (Status)) {
 162     Status = File->Read (File, &FdtSize, (VOID*)(UINTN)(FdtBase));
 163     if (EFI_ERROR (Status)) {
 164       gBS->FreePages (FdtBase, EFI_SIZE_TO_PAGES (FdtSize));
 165     } else {
 166       // Install the FDT as part of the UEFI Configuration Table
 167       Status = InstallFdtIntoConfigurationTable ((VOID*)(UINTN)FdtBase, FdtSize);
 168       if (EFI_ERROR (Status)) {
 169         gBS->FreePages (FdtBase, EFI_SIZE_TO_PAGES (FdtSize));
 170       }
 171     }
 172   }
 173
 174 CLOSE_FILES:
 175   File->Close (File);
 176   Fs->Close (Fs);
 177   return Status;
 178 }