freeldr/freeldr/disk/geometry.c

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 1998-2002  Brian Palmer  <brianp@sginet.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <freeldr.h>
  21 #include <disk.h>
  22 #include <rtl.h>
  23 #include <mm.h>
  24
  25
  26 typedef struct
  27 {
  28         LIST_ITEM       ListEntry;
  29
  30         ULONG           DriveNumber;
  31         GEOMETRY        DriveGeometry;
  32
  33 } DRIVE_GEOMETRY, *PDRIVE_GEOMETRY;
  34
  35
  36 PDRIVE_GEOMETRY DriveGeometryListHead = NULL;
  37
  38
  39 BOOL DiskGetDriveGeometry(ULONG DriveNumber, PGEOMETRY DriveGeometry)
  40 {
  41         PDRIVE_GEOMETRY DriveGeometryListEntry;
  42
  43         //
  44         // Search the drive geometry list for the requested drive
  45         //
  46         DriveGeometryListEntry = DriveGeometryListHead;
  47         while (DriveGeometryListEntry != NULL)
  48         {
  49                 //
  50                 // Check to see if this is the drive we want
  51                 //
  52                 if (DriveGeometryListEntry->DriveNumber == DriveNumber)
  53                 {
  54                         //
  55                         // Yep - return the information
  56                         //
  57                         RtlCopyMemory(DriveGeometry, &DriveGeometryListEntry->DriveGeometry, sizeof(GEOMETRY));
  58                         return TRUE;
  59                 }
  60
  61                 //
  62                 // Nope, get next item
  63                 //
  64                 DriveGeometryListEntry = (PDRIVE_GEOMETRY)RtlListGetNext((PLIST_ITEM)DriveGeometryListEntry);
  65         }
  66
  67         DiskError("Drive geometry unknown.");
  68         return FALSE;
  69 }
  70
  71 BOOL DiskSetDriveGeometry(ULONG DriveNumber, ULONG Cylinders, ULONG Heads, ULONG Sectors, ULONG BytesPerSector)
  72 {
  73         PDRIVE_GEOMETRY DriveGeometryListEntry;
  74
  75         //
  76         // Search the drive geometry list for the requested drive
  77         //
  78         DriveGeometryListEntry = DriveGeometryListHead;
  79         while (DriveGeometryListEntry != NULL)
  80         {
  81                 //
  82                 // Check to see if this is the drive
  83                 //
  84                 if (DriveGeometryListEntry->DriveNumber == DriveNumber)
  85                 {
  86                         //
  87                         // Yes, we already have this drive's geometry information
  88                         // so just return
  89                         //
  90                         return TRUE;
  91                 }
  92
  93                 //
  94                 // Nope, get next item
  95                 //
  96                 DriveGeometryListEntry = (PDRIVE_GEOMETRY)RtlListGetNext((PLIST_ITEM)DriveGeometryListEntry);
  97         }
  98
  99         //
 100         // If we get here then this is a new drive and we have
 101         // to add it's information to our list
 102         //
 103         DriveGeometryListEntry = (PDRIVE_GEOMETRY)AllocateMemory(sizeof(DRIVE_GEOMETRY));
 104         if (DriveGeometryListEntry == NULL)
 105         {
 106                 return FALSE;
 107         }
 108
 109         RtlZeroMemory(DriveGeometryListEntry, sizeof(DRIVE_GEOMETRY));
 110         DriveGeometryListEntry->DriveNumber = DriveNumber;
 111         DriveGeometryListEntry->DriveGeometry.Cylinders = Cylinders;
 112         DriveGeometryListEntry->DriveGeometry.Heads = Heads;
 113         DriveGeometryListEntry->DriveGeometry.Sectors = Sectors;
 114         DriveGeometryListEntry->DriveGeometry.BytesPerSector = BytesPerSector;
 115
 116         if (DriveGeometryListHead == NULL)
 117         {
 118                 DriveGeometryListHead = DriveGeometryListEntry;
 119         }
 120         else
 121         {
 122                 RtlListInsertTail((PLIST_ITEM)DriveGeometryListHead, (PLIST_ITEM)DriveGeometryListEntry);
 123         }
 124
 125         return TRUE;
 126 }