ArmVirtPkg/PrePi/FdtParser.c

   1 /*
   2  * Copyright (c) 2015, Linaro Ltd. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-2-Clause-Patent
   5  */
   6
   7 #include <Uefi.h>
   8 #include <Include/libfdt.h>
   9
  10 BOOLEAN
  11 FindMemnode (
  12   IN  VOID    *DeviceTreeBlob,
  13   OUT UINT64  *SystemMemoryBase,
  14   OUT UINT64  *SystemMemorySize
  15   )
  16 {
  17   INT32         MemoryNode;
  18   INT32         AddressCells;
  19   INT32         SizeCells;
  20   INT32         Length;
  21   CONST INT32   *Prop;
  22
  23   if (fdt_check_header (DeviceTreeBlob) != 0) {
  24     return FALSE;
  25   }
  26
  27   //
  28   // Look for a node called "memory" at the lowest level of the tree
  29   //
  30   MemoryNode = fdt_path_offset (DeviceTreeBlob, "/memory");
  31   if (MemoryNode <= 0) {
  32     return FALSE;
  33   }
  34
  35   //
  36   // Retrieve the #address-cells and #size-cells properties
  37   // from the root node, or use the default if not provided.
  38   //
  39   AddressCells = 1;
  40   SizeCells = 1;
  41
  42   Prop = fdt_getprop (DeviceTreeBlob, 0, "#address-cells", &Length);
  43   if (Length == 4) {
  44     AddressCells = fdt32_to_cpu (*Prop);
  45   }
  46
  47   Prop = fdt_getprop (DeviceTreeBlob, 0, "#size-cells", &Length);
  48   if (Length == 4) {
  49     SizeCells = fdt32_to_cpu (*Prop);
  50   }
  51
  52   //
  53   // Now find the 'reg' property of the /memory node, and read the first
  54   // range listed.
  55   //
  56   Prop = fdt_getprop (DeviceTreeBlob, MemoryNode, "reg", &Length);
  57
  58   if (Length < (AddressCells + SizeCells) * sizeof (INT32)) {
  59     return FALSE;
  60   }
  61
  62   *SystemMemoryBase = fdt32_to_cpu (Prop[0]);
  63   if (AddressCells > 1) {
  64     *SystemMemoryBase = (*SystemMemoryBase << 32) | fdt32_to_cpu (Prop[1]);
  65   }
  66   Prop += AddressCells;
  67
  68   *SystemMemorySize = fdt32_to_cpu (Prop[0]);
  69   if (SizeCells > 1) {
  70     *SystemMemorySize = (*SystemMemorySize << 32) | fdt32_to_cpu (Prop[1]);
  71   }
  72
  73   return TRUE;
  74 }
  75
  76 VOID
  77 CopyFdt (
  78   IN    VOID    *FdtDest,
  79   IN    VOID    *FdtSource
  80   )
  81 {
  82   fdt_pack(FdtSource);
  83   CopyMem (FdtDest, FdtSource, fdt_totalsize (FdtSource));
  84 }