PFREELDR_MEMORY_DESCRIPTOR
PcMemGetMemoryMap(ULONG *MemoryMapSize)
{
ULONG i, EntryCount;
ULONG ExtendedMemorySizeAtOneMB;
ULONG ExtendedMemorySizeAtSixteenMB;
EntryCount = PcMemGetBiosMemoryMap(PcMemoryMap, MAX_BIOS_DESCRIPTORS);
/* If the BIOS didn't provide a memory map, synthesize one */
if (0 == EntryCount)
{
GetExtendedMemoryConfiguration(&ExtendedMemorySizeAtOneMB, &ExtendedMemorySizeAtSixteenMB);
/* Conventional memory */
AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
0,
PcMemGetConventionalMemorySize() * 1024 / PAGE_SIZE,
LoaderFree);
/* Extended memory */
EntryCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
1024 * 1024 / PAGE_SIZE,
ExtendedMemorySizeAtOneMB * 1024 / PAGE_SIZE,
LoaderFree);
if (ExtendedMemorySizeAtSixteenMB != 0)
{
/* Extended memory at 16MB */
EntryCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
0x1000000 / PAGE_SIZE,
ExtendedMemorySizeAtSixteenMB * 64 * 1024 / PAGE_SIZE,
LoaderFree);
}
}
TRACE("Dumping resulting memory map:\n");
for (i = 0; i < EntryCount; i++)
{
TRACE("BasePage=0x%lx, PageCount=0x%lx, Type=%s\n",
PcMemoryMap[i].BasePage,
PcMemoryMap[i].PageCount,
MmGetSystemMemoryMapTypeString(PcMemoryMap[i].MemoryType));
}
*MemoryMapSize = EntryCount;
return PcMemoryMap;
}
PFREELDR_MEMORY_DESCRIPTOR
PcMemGetMemoryMap(ULONG *MemoryMapSize)
{
ULONG i, EntryCount;
ULONG ExtendedMemorySizeAtOneMB;
ULONG ExtendedMemorySizeAtSixteenMB;
ULONG EbdaBase, EbdaSize;
TRACE("PcMemGetMemoryMap()\n");
EntryCount = PcMemGetBiosMemoryMap(PcMemoryMap, MAX_BIOS_DESCRIPTORS);
/* If the BIOS didn't provide a memory map, synthesize one */
if (EntryCount == 0)
{
GetExtendedMemoryConfiguration(&ExtendedMemorySizeAtOneMB,
&ExtendedMemorySizeAtSixteenMB);
/* Conventional memory */
AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
0,
PcMemGetConventionalMemorySize() * 1024 / PAGE_SIZE,
LoaderFree);
/* Extended memory */
PcMapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
1024 * 1024 / PAGE_SIZE,
ExtendedMemorySizeAtOneMB * 1024 / PAGE_SIZE,
LoaderFree);
if (ExtendedMemorySizeAtSixteenMB != 0)
{
/* Extended memory at 16MB */
PcMapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
0x1000000 / PAGE_SIZE,
ExtendedMemorySizeAtSixteenMB * 64 * 1024 / PAGE_SIZE,
LoaderFree);
}
/* Check if we have an EBDA and get it's location */
if (GetEbdaLocation(&EbdaBase, &EbdaSize))
{
/* Add the descriptor */
PcMapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
(EbdaBase / PAGE_SIZE),
ADDRESS_AND_SIZE_TO_SPAN_PAGES(EbdaBase, EbdaSize),
LoaderFirmwarePermanent);
}
}
/* Setup some protected ranges */
SetMemory(0x000000, 0x01000, LoaderFirmwarePermanent); // Realmode IVT / BDA
SetMemory(0x0A0000, 0x50000, LoaderFirmwarePermanent); // Video memory
SetMemory(0x0F0000, 0x10000, LoaderSpecialMemory); // ROM
SetMemory(0xFFF000, 0x01000, LoaderSpecialMemory); // unusable memory (do we really need this?)
/* Reserve some static ranges for freeldr */
ReserveMemory(0x1000, STACKLOW - 0x1000, LoaderFirmwareTemporary, "BIOS area");
ReserveMemory(STACKLOW, STACKADDR - STACKLOW, LoaderOsloaderStack, "FreeLdr stack");
ReserveMemory(FREELDR_BASE, FrLdrImageSize, LoaderLoadedProgram, "FreeLdr image");
/* Default to 1 page above freeldr for the disk read buffer */
DiskReadBuffer = (PUCHAR)ALIGN_UP_BY(FREELDR_BASE + FrLdrImageSize, PAGE_SIZE);
DiskReadBufferSize = PAGE_SIZE;
/* Scan for free range above freeldr image */
for (i = 0; i < PcMapCount; i++)
{
if ((PcMemoryMap[i].BasePage > (FREELDR_BASE / PAGE_SIZE)) &&
(PcMemoryMap[i].MemoryType == LoaderFree))
{
/* Use this range for the disk read buffer */
DiskReadBuffer = (PVOID)(PcMemoryMap[i].BasePage * PAGE_SIZE);
DiskReadBufferSize = min(PcMemoryMap[i].PageCount * PAGE_SIZE,
MAX_DISKREADBUFFER_SIZE);
break;
}
}
TRACE("DiskReadBuffer=%p, DiskReadBufferSize=%lx\n",
DiskReadBuffer, DiskReadBufferSize);
/* Now reserve the range for the disk read buffer */
ReserveMemory((ULONG_PTR)DiskReadBuffer,
DiskReadBufferSize,
LoaderFirmwareTemporary,
"Disk read buffer");
TRACE("Dumping resulting memory map:\n");
for (i = 0; i < PcMapCount; i++)
{
TRACE("BasePage=0x%lx, PageCount=0x%lx, Type=%s\n",
PcMemoryMap[i].BasePage,
PcMemoryMap[i].PageCount,
MmGetSystemMemoryMapTypeString(PcMemoryMap[i].MemoryType));
}
*MemoryMapSize = PcMapCount;
return PcMemoryMap;
}