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

   1 /*
   2  *  FreeLoader
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  *  Note: much of this code was based on knowledge and/or code developed
  19  *  by the Xbox Linux group: http://www.xbox-linux.org
  20  */
  21
  22 #include <freeldr.h>
  23
  24 static ULONG InstalledMemoryMb = 0;
  25 static ULONG AvailableMemoryMb = 0;
  26
  27 #define TEST_SIZE     0x200
  28 #define TEST_PATTERN1 0xAA
  29 #define TEST_PATTERN2 0x55
  30
  31 VOID
  32 XboxMemInit(VOID)
  33 {
  34     UCHAR ControlRegion[TEST_SIZE];
  35     PVOID MembaseTop = (PVOID)(64 * 1024 * 1024);
  36     PVOID MembaseLow = (PVOID)0;
  37
  38     (*(PULONG)(0xfd000000 + 0x100200)) = 0x03070103;
  39     (*(PULONG)(0xfd000000 + 0x100204)) = 0x11448000;
  40
  41     WRITE_PORT_ULONG((ULONG*) 0xcf8, CONFIG_CMD(0, 0, 0x84));
  42     WRITE_PORT_ULONG((ULONG*) 0xcfc, 0x7ffffff);             /* Prep hardware for 128 Mb */
  43
  44     InstalledMemoryMb = 64;
  45     memset(ControlRegion, TEST_PATTERN1, TEST_SIZE);
  46     memset(MembaseTop, TEST_PATTERN1, TEST_SIZE);
  47     __wbinvd();
  48
  49     if (memcmp(MembaseTop, ControlRegion, TEST_SIZE) == 0)
  50     {
  51         /* Looks like there is memory .. maybe a 128MB box */
  52         memset(ControlRegion, TEST_PATTERN2, TEST_SIZE);
  53         memset(MembaseTop, TEST_PATTERN2, TEST_SIZE);
  54         __wbinvd();
  55         if (memcmp(MembaseTop, ControlRegion, TEST_SIZE) == 0)
  56         {
  57             /* Definitely looks like there is memory */
  58             if (memcmp(MembaseLow, ControlRegion, TEST_SIZE) == 0)
  59             {
  60                 /* Hell, we find the Test-string at 0x0 too! */
  61                 InstalledMemoryMb = 64;
  62             }
  63             else
  64             {
  65                 InstalledMemoryMb = 128;
  66             }
  67         }
  68     }
  69
  70     /* Set hardware for amount of memory detected */
  71     WRITE_PORT_ULONG((ULONG*) 0xcf8, CONFIG_CMD(0, 0, 0x84));
  72     WRITE_PORT_ULONG((ULONG*) 0xcfc, InstalledMemoryMb * 1024 * 1024 - 1);
  73
  74     AvailableMemoryMb = InstalledMemoryMb;
  75 }
  76
  77 FREELDR_MEMORY_DESCRIPTOR XboxMemoryMap[2];
  78
  79 PFREELDR_MEMORY_DESCRIPTOR
  80 XboxMemGetMemoryMap(ULONG *MemoryMapSize)
  81 {
  82     /* Synthesize memory map */
  83
  84     /* Available RAM block */
  85     XboxMemoryMap[0].BasePage = 0;
  86     XboxMemoryMap[0].PageCount = AvailableMemoryMb * 1024 * 1024 / MM_PAGE_SIZE;
  87     XboxMemoryMap[0].MemoryType = LoaderFree;
  88
  89     /* Video memory */
  90     XboxMemoryMap[1].BasePage = AvailableMemoryMb * 1024 * 1024 / MM_PAGE_SIZE;
  91     XboxMemoryMap[1].PageCount = (InstalledMemoryMb - AvailableMemoryMb) * 1024 * 1024 / MM_PAGE_SIZE;
  92     XboxMemoryMap[1].MemoryType = LoaderFirmwarePermanent;
  93
  94     *MemoryMapSize = 2;
  95     return XboxMemoryMap;
  96 }
  97
  98 PVOID
  99 XboxMemReserveMemory(ULONG MbToReserve)
 100 {
 101     if (InstalledMemoryMb == 0)
 102     {
 103         /* Hmm, seems we're not initialized yet */
 104         XboxMemInit();
 105     }
 106
 107     if (MbToReserve > AvailableMemoryMb)
 108     {
 109         /* Can't satisfy the request */
 110         return NULL;
 111     }
 112
 113     AvailableMemoryMb -= MbToReserve;
 114
 115     /* Top of available memory points to the space just reserved */
 116     return (PVOID)(AvailableMemoryMb * 1024 * 1024);
 117 }
 118
 119 /* EOF */