ArmVirtPkg/PrePi/FdtParser.c

   1 /*
   2  * Copyright (c) 2015, Linaro Ltd. All rights reserved.
   3  *
   4  * This program and the accompanying materials
   5  * are licensed and made available under the terms and conditions of the BSD License
   6  * which accompanies this distribution.  The full text of the license may be found at
   7  * http://opensource.org/licenses/bsd-license.php
   8  *
   9  * THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10  * WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11  */
  12
  13 #include <Uefi.h>
  14 #include <Include/libfdt.h>
  15
  16 BOOLEAN
  17 FindMemnode (
  18   IN  VOID    *DeviceTreeBlob,
  19   OUT UINT64  *SystemMemoryBase,
  20   OUT UINT64  *SystemMemorySize
  21   )
  22 {
  23   INT32         MemoryNode;
  24   INT32         AddressCells;
  25   INT32         SizeCells;
  26   INT32         Length;
  27   CONST INT32   *Prop;
  28
  29   if (fdt_check_header (DeviceTreeBlob) != 0) {
  30     return FALSE;
  31   }
  32
  33   //
  34   // Look for a node called "memory" at the lowest level of the tree
  35   //
  36   MemoryNode = fdt_path_offset (DeviceTreeBlob, "/memory");
  37   if (MemoryNode <= 0) {
  38     return FALSE;
  39   }
  40
  41   //
  42   // Retrieve the #address-cells and #size-cells properties
  43   // from the root node, or use the default if not provided.
  44   //
  45   AddressCells = 1;
  46   SizeCells = 1;
  47
  48   Prop = fdt_getprop (DeviceTreeBlob, 0, "#address-cells", &Length);
  49   if (Length == 4) {
  50     AddressCells = fdt32_to_cpu (*Prop);
  51   }
  52
  53   Prop = fdt_getprop (DeviceTreeBlob, 0, "#size-cells", &Length);
  54   if (Length == 4) {
  55     SizeCells = fdt32_to_cpu (*Prop);
  56   }
  57
  58   //
  59   // Now find the 'reg' property of the /memory node, and read the first
  60   // range listed.
  61   //
  62   Prop = fdt_getprop (DeviceTreeBlob, MemoryNode, "reg", &Length);
  63
  64   if (Length < (AddressCells + SizeCells) * sizeof (INT32)) {
  65     return FALSE;
  66   }
  67
  68   *SystemMemoryBase = fdt32_to_cpu (Prop[0]);
  69   if (AddressCells > 1) {
  70     *SystemMemoryBase = (*SystemMemoryBase << 32) | fdt32_to_cpu (Prop[1]);
  71   }
  72   Prop += AddressCells;
  73
  74   *SystemMemorySize = fdt32_to_cpu (Prop[0]);
  75   if (SizeCells > 1) {
  76     *SystemMemorySize = (*SystemMemorySize << 32) | fdt32_to_cpu (Prop[1]);
  77   }
  78
  79   return TRUE;
  80 }
  81
  82 VOID
  83 CopyFdt (
  84   IN    VOID    *FdtDest,
  85   IN    VOID    *FdtSource
  86   )
  87 {
  88   fdt_pack(FdtSource);
  89   CopyMem (FdtDest, FdtSource, fdt_totalsize (FdtSource));
  90 }