#include <freeldr.h>

Include dependency graph for xboxmem.c:

Macros
#define	TEST_SIZE 0x200

#define	TEST_PATTERN1 0xaa

#define	TEST_PATTERN2 0x55

Functions
VOID	XboxMemInit (VOID)

PFREELDR_MEMORY_DESCRIPTOR	XboxMemGetMemoryMap (ULONG *MemoryMapSize)

PVOID	XboxMemReserveMemory (ULONG MbToReserve)

Variables
static ULONG	InstalledMemoryMb = 0

static ULONG	AvailableMemoryMb = 0

FREELDR_MEMORY_DESCRIPTOR	XboxMemoryMap [2]

Macro Definition Documentation

◆ TEST_PATTERN1

#define TEST_PATTERN1 0xaa

Definition at line 28 of file xboxmem.c.

◆ TEST_PATTERN2

#define TEST_PATTERN2 0x55

Definition at line 29 of file xboxmem.c.

◆ TEST_SIZE

#define TEST_SIZE 0x200

Definition at line 27 of file xboxmem.c.

Function Documentation

◆ XboxMemGetMemoryMap()

PFREELDR_MEMORY_DESCRIPTOR XboxMemGetMemoryMap ( ULONG * MemoryMapSize )

Definition at line 80 of file xboxmem.c.

 {
   /* Synthesize memory map */
       /* Available RAM block */
       XboxMemoryMap[0].BasePage = 0;
       XboxMemoryMap[0].PageCount = AvailableMemoryMb * 1024 * 1024 / MM_PAGE_SIZE;
       XboxMemoryMap[0].MemoryType = LoaderFree;
 
       /* Video memory */
       XboxMemoryMap[1].BasePage = AvailableMemoryMb * 1024 * 1024 / MM_PAGE_SIZE;
       XboxMemoryMap[1].PageCount = (InstalledMemoryMb - AvailableMemoryMb) * 1024 * 1024 / MM_PAGE_SIZE;
       XboxMemoryMap[1].MemoryType = LoaderFirmwarePermanent;
 
   *MemoryMapSize = 2;
   return XboxMemoryMap;
 }

Referenced by XboxMachInit().

◆ XboxMemInit()

VOID XboxMemInit ( VOID )

Definition at line 32 of file xboxmem.c.

 {
   UCHAR ControlRegion[TEST_SIZE];
   PVOID MembaseTop = (PVOID)(64 * 1024 * 1024);
   PVOID MembaseLow = (PVOID)0;
 
   (*(PULONG)(0xfd000000 + 0x100200)) = 0x03070103 ;
   (*(PULONG)(0xfd000000 + 0x100204)) = 0x11448000 ;
 
   WRITE_PORT_ULONG((ULONG*) 0xcf8, CONFIG_CMD(0, 0, 0x84));
   WRITE_PORT_ULONG((ULONG*) 0xcfc, 0x7ffffff);             /* Prep hardware for 128 Mb */
 
   InstalledMemoryMb = 64;
   memset(ControlRegion, TEST_PATTERN1, TEST_SIZE);
   memset(MembaseTop, TEST_PATTERN1, TEST_SIZE);
   __wbinvd();
 
   if (0 == memcmp(MembaseTop, ControlRegion, TEST_SIZE))
     {
       /* Looks like there is memory .. maybe a 128MB box */
       memset(ControlRegion, TEST_PATTERN2, TEST_SIZE);
       memset(MembaseTop, TEST_PATTERN2, TEST_SIZE);
       __wbinvd();
       if (0 == memcmp(MembaseTop, ControlRegion, TEST_SIZE))
         {
           /* Definitely looks like there is memory */
           if (0 == memcmp(MembaseLow, ControlRegion, TEST_SIZE))
             {
               /* Hell, we find the Test-string at 0x0 too ! */
               InstalledMemoryMb = 64;
             }
           else
             {
               InstalledMemoryMb = 128;
             }
         }
     }
 
   /* Set hardware for amount of memory detected */
   WRITE_PORT_ULONG((ULONG*) 0xcf8, CONFIG_CMD(0, 0, 0x84));
   WRITE_PORT_ULONG((ULONG*) 0xcfc, InstalledMemoryMb * 1024 * 1024 - 1);
 
   AvailableMemoryMb = InstalledMemoryMb;
 }

Referenced by XboxMachInit(), and XboxMemReserveMemory().

◆ XboxMemReserveMemory()

PVOID XboxMemReserveMemory ( ULONG MbToReserve )

Definition at line 98 of file xboxmem.c.

 {
   if (0 == InstalledMemoryMb)
     {
       /* Hmm, seems we're not initialized yet */
       XboxMemInit();
     }
 
   if (AvailableMemoryMb < MbToReserve)
     {
       /* Can't satisfy the request */
       return NULL;
     }
 
   AvailableMemoryMb -= MbToReserve;
 
   /* Top of available memory points to the space just reserved */
   return (PVOID) (AvailableMemoryMb * 1024 * 1024);
 }