ArmPkg/Library/BdsLib/BdsLinuxAtag.c

   1 /** @file
   2 *
   3 *  Copyright (c) 2011-2012, 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 "BdsInternal.h"
  16 #include "BdsLinuxLoader.h"
  17
  18 // Point to the current ATAG
  19 STATIC LINUX_ATAG *mLinuxKernelCurrentAtag;
  20
  21 STATIC
  22 VOID
  23 SetupCoreTag (
  24   IN UINT32 PageSize
  25   )
  26 {
  27   mLinuxKernelCurrentAtag->header.size = tag_size(LINUX_ATAG_CORE);
  28   mLinuxKernelCurrentAtag->header.type = ATAG_CORE;
  29
  30   mLinuxKernelCurrentAtag->body.core_tag.flags    = 1;            /* ensure read-only */
  31   mLinuxKernelCurrentAtag->body.core_tag.pagesize = PageSize;     /* systems PageSize (4k) */
  32   mLinuxKernelCurrentAtag->body.core_tag.rootdev  = 0;            /* zero root device (typically overridden from kernel command line )*/
  33
  34   // move pointer to next tag
  35   mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
  36 }
  37
  38 STATIC
  39 VOID
  40 SetupMemTag (
  41   IN UINTN StartAddress,
  42   IN UINT32 Size
  43   )
  44 {
  45   mLinuxKernelCurrentAtag->header.size = tag_size(LINUX_ATAG_MEM);
  46   mLinuxKernelCurrentAtag->header.type = ATAG_MEM;
  47
  48   mLinuxKernelCurrentAtag->body.mem_tag.start = StartAddress;    /* Start of memory chunk for AtagMem */
  49   mLinuxKernelCurrentAtag->body.mem_tag.size  = Size;             /* Size of memory chunk for AtagMem */
  50
  51   // move pointer to next tag
  52   mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
  53 }
  54
  55 STATIC
  56 VOID
  57 SetupCmdlineTag (
  58   IN CONST CHAR8 *CmdLine
  59   )
  60 {
  61   UINT32 LineLength;
  62
  63   // Increment the line length by 1 to account for the null string terminator character
  64   LineLength = AsciiStrLen(CmdLine) + 1;
  65
  66   /* Check for NULL strings.
  67    * Do not insert a tag for an empty CommandLine, don't even modify the tag address pointer.
  68    * Remember, you have at least one null string terminator character.
  69    */
  70   if(LineLength > 1) {
  71     mLinuxKernelCurrentAtag->header.size = ((UINT32)sizeof(LINUX_ATAG_HEADER) + LineLength + (UINT32)3) >> 2;
  72     mLinuxKernelCurrentAtag->header.type = ATAG_CMDLINE;
  73
  74     /* place CommandLine into tag */
  75     AsciiStrCpy(mLinuxKernelCurrentAtag->body.cmdline_tag.cmdline, CmdLine);
  76
  77     // move pointer to next tag
  78     mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
  79   }
  80 }
  81
  82 STATIC
  83 VOID
  84 SetupInitrdTag (
  85   IN UINT32 InitrdImage,
  86   IN UINT32 InitrdImageSize
  87   )
  88 {
  89   mLinuxKernelCurrentAtag->header.size = tag_size(LINUX_ATAG_INITRD2);
  90   mLinuxKernelCurrentAtag->header.type = ATAG_INITRD2;
  91
  92   mLinuxKernelCurrentAtag->body.initrd2_tag.start = InitrdImage;
  93   mLinuxKernelCurrentAtag->body.initrd2_tag.size = InitrdImageSize;
  94
  95   // Move pointer to next tag
  96   mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
  97 }
  98 STATIC
  99 VOID
 100 SetupEndTag (
 101   VOID
 102   )
 103 {
 104   // Empty tag ends list; this has zero length and no body
 105   mLinuxKernelCurrentAtag->header.type = ATAG_NONE;
 106   mLinuxKernelCurrentAtag->header.size = 0;
 107
 108   /* We can not calculate the next address by using the standard macro:
 109    * Params = next_tag_address(Params);
 110    * because it relies on the header.size, which here it is 0 (zero).
 111    * The easiest way is to add the sizeof(mLinuxKernelCurrentAtag->header).
 112    */
 113   mLinuxKernelCurrentAtag = (LINUX_ATAG*)((UINT32)mLinuxKernelCurrentAtag + sizeof(mLinuxKernelCurrentAtag->header));
 114 }
 115
 116 EFI_STATUS
 117 PrepareAtagList (
 118   IN  CONST CHAR8*          CommandLineString,
 119   IN  EFI_PHYSICAL_ADDRESS  InitrdImage,
 120   IN  UINTN                 InitrdImageSize,
 121   OUT EFI_PHYSICAL_ADDRESS  *AtagBase,
 122   OUT UINT32                *AtagSize
 123   )
 124 {
 125   EFI_STATUS                  Status;
 126   LIST_ENTRY                  *ResourceLink;
 127   LIST_ENTRY                  ResourceList;
 128   EFI_PHYSICAL_ADDRESS        AtagStartAddress;
 129   BDS_SYSTEM_MEMORY_RESOURCE  *Resource;
 130
 131   AtagStartAddress = LINUX_ATAG_MAX_OFFSET;
 132   Status = gBS->AllocatePages (AllocateMaxAddress, EfiBootServicesData, EFI_SIZE_TO_PAGES(ATAG_MAX_SIZE), &AtagStartAddress);
 133   if (EFI_ERROR(Status)) {
 134     DEBUG ((EFI_D_WARN, "Warning: Failed to allocate Atag at 0x%lX (%r). The Atag will be allocated somewhere else in System Memory.\n", AtagStartAddress, Status));
 135     Status = gBS->AllocatePages (AllocateAnyPages, EfiBootServicesData, EFI_SIZE_TO_PAGES(ATAG_MAX_SIZE), &AtagStartAddress);
 136     ASSERT_EFI_ERROR(Status);
 137   }
 138
 139   // Ready to setup the atag list
 140   mLinuxKernelCurrentAtag = (LINUX_ATAG*)(UINTN)AtagStartAddress;
 141
 142   // Standard core tag 4k PageSize
 143   SetupCoreTag( (UINT32)SIZE_4KB );
 144
 145   // Physical memory setup
 146   GetSystemMemoryResources (&ResourceList);
 147   ResourceLink = ResourceList.ForwardLink;
 148   while (ResourceLink != NULL && ResourceLink != &ResourceList) {
 149     Resource = (BDS_SYSTEM_MEMORY_RESOURCE*)ResourceLink;
 150     DEBUG((EFI_D_INFO,"- [0x%08X,0x%08X]\n",(UINT32)Resource->PhysicalStart,(UINT32)Resource->PhysicalStart+(UINT32)Resource->ResourceLength));
 151     SetupMemTag( (UINT32)Resource->PhysicalStart, (UINT32)Resource->ResourceLength );
 152     ResourceLink = ResourceLink->ForwardLink;
 153   }
 154
 155   // CommandLine setting root device
 156   if (CommandLineString) {
 157     SetupCmdlineTag (CommandLineString);
 158   }
 159
 160   if (InitrdImageSize > 0 && InitrdImage != 0) {
 161     SetupInitrdTag ((UINT32)InitrdImage, (UINT32)InitrdImageSize);
 162   }
 163
 164   // End of tags
 165   SetupEndTag();
 166
 167   // Calculate atag list size
 168   *AtagBase = AtagStartAddress;
 169   *AtagSize = (UINT32)mLinuxKernelCurrentAtag - (UINT32)AtagStartAddress + 1;
 170
 171   return EFI_SUCCESS;
 172 }
 173