reactos/boot/freeldr/freeldr/arch/i386/xboxmem.c

   1 /* $Id$
   2  *
   3  *  FreeLoader
   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 along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Note: much of this code was based on knowledge and/or code developed
  20  * by the Xbox Linux group: http://www.xbox-linux.org
  21  */
  22
  23 #include <freeldr.h>
  24
  25 static ULONG InstalledMemoryMb = 0;
  26 static ULONG AvailableMemoryMb = 0;
  27
  28 #define TEST_SIZE     0x200
  29 #define TEST_PATTERN1 0xaa
  30 #define TEST_PATTERN2 0x55
  31
  32 VOID
  33 XboxMemInit(VOID)
  34 {
  35   UCHAR ControlRegion[TEST_SIZE];
  36   PVOID MembaseTop = (PVOID)(64 * 1024 * 1024);
  37   PVOID MembaseLow = (PVOID)0;
  38
  39   (*(PULONG)(0xfd000000 + 0x100200)) = 0x03070103 ;
  40   (*(PULONG)(0xfd000000 + 0x100204)) = 0x11448000 ;
  41
  42   WRITE_PORT_ULONG((ULONG*) 0xcf8, CONFIG_CMD(0, 0, 0x84));
  43   WRITE_PORT_ULONG((ULONG*) 0xcfc, 0x7ffffff);             /* Prep hardware for 128 Mb */
  44
  45   InstalledMemoryMb = 64;
  46   memset(ControlRegion, TEST_PATTERN1, TEST_SIZE);
  47   memset(MembaseTop, TEST_PATTERN1, TEST_SIZE);
  48   __wbinvd();
  49
  50   if (0 == memcmp(MembaseTop, ControlRegion, TEST_SIZE))
  51     {
  52       /* Looks like there is memory .. maybe a 128MB box */
  53       memset(ControlRegion, TEST_PATTERN2, TEST_SIZE);
  54       memset(MembaseTop, TEST_PATTERN2, TEST_SIZE);
  55       __wbinvd();
  56       if (0 == memcmp(MembaseTop, ControlRegion, TEST_SIZE))
  57         {
  58           /* Definitely looks like there is memory */
  59           if (0 == memcmp(MembaseLow, ControlRegion, TEST_SIZE))
  60             {
  61               /* Hell, we find the Test-string at 0x0 too ! */
  62               InstalledMemoryMb = 64;
  63             }
  64           else
  65             {
  66               InstalledMemoryMb = 128;
  67             }
  68         }
  69     }
  70
  71   /* Set hardware for amount of memory detected */
  72   WRITE_PORT_ULONG((ULONG*) 0xcf8, CONFIG_CMD(0, 0, 0x84));
  73   WRITE_PORT_ULONG((ULONG*) 0xcfc, InstalledMemoryMb * 1024 * 1024 - 1);
  74
  75   AvailableMemoryMb = InstalledMemoryMb;
  76 }
  77
  78 ULONG
  79 XboxMemGetMemoryMap(PBIOS_MEMORY_MAP BiosMemoryMap, ULONG MaxMemoryMapSize)
  80 {
  81   ULONG EntryCount = 0;
  82
  83   /* Synthesize memory map */
  84   if (1 <= MaxMemoryMapSize)
  85     {
  86       /* Available RAM block */
  87       BiosMemoryMap[0].BaseAddress = 0;
  88       BiosMemoryMap[0].Length = AvailableMemoryMb * 1024 * 1024;
  89       BiosMemoryMap[0].Type = BiosMemoryUsable;
  90       EntryCount = 1;
  91     }
  92
  93   if (2 <= MaxMemoryMapSize)
  94     {
  95       /* Video memory */
  96       BiosMemoryMap[1].BaseAddress = AvailableMemoryMb * 1024 * 1024;
  97       BiosMemoryMap[1].Length = (InstalledMemoryMb - AvailableMemoryMb) * 1024 * 1024;
  98       BiosMemoryMap[1].Type = BiosMemoryReserved;
  99       EntryCount = 2;
 100     }
 101
 102   return EntryCount;
 103 }
 104
 105 PVOID
 106 XboxMemReserveMemory(ULONG MbToReserve)
 107 {
 108   if (0 == InstalledMemoryMb)
 109     {
 110       /* Hmm, seems we're not initialized yet */
 111       XboxMemInit();
 112     }
 113
 114   if (AvailableMemoryMb < MbToReserve)
 115     {
 116       /* Can't satisfy the request */
 117       return NULL;
 118     }
 119
 120   AvailableMemoryMb -= MbToReserve;
 121
 122   /* Top of available memory points to the space just reserved */
 123   return (PVOID) (AvailableMemoryMb * 1024 * 1024);
 124 }
 125
 126 /* EOF */