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;
}
VOID
SetMemory(
ULONG_PTR BaseAddress,
SIZE_T Size,
TYPE_OF_MEMORY MemoryType)
{
ULONG_PTR BasePage, PageCount;
BasePage = BaseAddress / PAGE_SIZE;
PageCount = ADDRESS_AND_SIZE_TO_SPAN_PAGES(BaseAddress, Size);
/* Add the memory descriptor */
PcMapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
BasePage,
PageCount,
MemoryType);
}
VOID
ReserveMemory(
ULONG_PTR BaseAddress,
SIZE_T Size,
TYPE_OF_MEMORY MemoryType,
PCHAR Usage)
{
ULONG_PTR BasePage, PageCount;
ULONG i;
BasePage = BaseAddress / PAGE_SIZE;
PageCount = ADDRESS_AND_SIZE_TO_SPAN_PAGES(BaseAddress, Size);
for (i = 0; i < PcMapCount; i++)
{
/* Check for conflicting descriptor */
if ((PcMemoryMap[i].BasePage < BasePage + PageCount) &&
(PcMemoryMap[i].BasePage + PcMemoryMap[i].PageCount > BasePage))
{
/* Check if the memory is free */
if (PcMemoryMap[i].MemoryType != LoaderFree)
{
FrLdrBugCheckWithMessage(
MEMORY_INIT_FAILURE,
__FILE__,
__LINE__,
"Failed to reserve memory in the range 0x%Ix - 0x%Ix for %s",
BaseAddress,
Size,
Usage);
}
}
}
/* Add the memory descriptor */
PcMapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
BasePage,
PageCount,
MemoryType);
}
static
ULONG
PcMemGetBiosMemoryMap(PFREELDR_MEMORY_DESCRIPTOR MemoryMap, ULONG MaxMemoryMapSize)
{
REGS Regs;
ULONG MapCount = 0;
ULONGLONG RealBaseAddress, RealSize;
TYPE_OF_MEMORY MemoryType;
ULONG Size;
ASSERT(PcBiosMapCount == 0);
TRACE("GetBiosMemoryMap()\n");
/* Make sure the usable memory is large enough. To do this we check the 16
bit value at address 0x413 inside the BDA, which gives us the usable size
in KB */
Size = (*(PUSHORT)(ULONG_PTR)0x413) * 1024;
if (Size < MEMORY_MARGIN)
{
FrLdrBugCheckWithMessage(
MEMORY_INIT_FAILURE,
__FILE__,
__LINE__,
"The BIOS reported a usable memory range up to 0x%x, which is too small!\n\n"
"If you see this, please report to the ReactOS team!",
Size);
}
/* Get the address of the Extended BIOS Data Area (EBDA).
* Int 15h, AH=C1h
* SYSTEM - RETURN EXTENDED-BIOS DATA-AREA SEGMENT ADDRESS (PS)
*
* Return:
* CF set on error
* CF clear if successful
* ES = segment of data area
*/
Regs.x.eax = 0x0000C100;
Int386(0x15, &Regs, &Regs);
/* If the function fails, there is no EBDA */
if (INT386_SUCCESS(Regs))
{
/* Check if this is high enough */
ULONG EbdaBase = (ULONG)Regs.w.es << 4;
if (EbdaBase < MEMORY_MARGIN)
{
FrLdrBugCheckWithMessage(
MEMORY_INIT_FAILURE,
__FILE__,
__LINE__,
"The location of your EBDA is 0x%lx, which is too low!\n\n"
"If you see this, please report to the ReactOS team!",
EbdaBase);
}
/* Calculate the (max) size of the EBDA */
Size = 0xA0000 - EbdaBase;
/* Add the descriptor */
MapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
(EbdaBase / MM_PAGE_SIZE),
(Size / MM_PAGE_SIZE),
LoaderFirmwarePermanent);
}
/* Int 15h AX=E820h
* Newer BIOSes - GET SYSTEM MEMORY MAP
*
* AX = E820h
* EAX = 0000E820h
* EDX = 534D4150h ('SMAP')
* EBX = continuation value or 00000000h to start at beginning of map
* ECX = size of buffer for result, in bytes (should be >= 20 bytes)
* ES:DI -> buffer for result
* Return:
* CF clear if successful
* EAX = 534D4150h ('SMAP')
* ES:DI buffer filled
* EBX = next offset from which to copy or 00000000h if all done
* ECX = actual length returned in bytes
* CF set on error
* AH = error code (86h)
*/
Regs.x.ebx = 0x00000000;
while (PcBiosMapCount < MAX_BIOS_DESCRIPTORS)
{
/* Setup the registers for the BIOS call */
Regs.x.eax = 0x0000E820;
Regs.x.edx = 0x534D4150; /* ('SMAP') */
/* Regs.x.ebx = 0x00000001; Continuation value already set */
Regs.x.ecx = sizeof(BIOS_MEMORY_MAP);
Regs.w.es = BIOSCALLBUFSEGMENT;
Regs.w.di = BIOSCALLBUFOFFSET;
Int386(0x15, &Regs, &Regs);
TRACE("Memory Map Entry %d\n", PcBiosMapCount);
TRACE("Int15h AX=E820h\n");
TRACE("EAX = 0x%x\n", Regs.x.eax);
TRACE("EBX = 0x%x\n", Regs.x.ebx);
TRACE("ECX = 0x%x\n", Regs.x.ecx);
TRACE("CF set = %s\n", (Regs.x.eflags & EFLAGS_CF) ? "TRUE" : "FALSE");
/* If the BIOS didn't return 'SMAP' in EAX then
* it doesn't support this call. If CF is set, we're done */
if (Regs.x.eax != 0x534D4150 || !INT386_SUCCESS(Regs))
{
break;
}
/* Copy data to global buffer */
RtlCopyMemory(&PcBiosMemoryMap[PcBiosMapCount], (PVOID)BIOSCALLBUFFER, Regs.x.ecx);
TRACE("BaseAddress: 0x%llx\n", PcBiosMemoryMap[PcBiosMapCount].BaseAddress);
TRACE("Length: 0x%llx\n", PcBiosMemoryMap[PcBiosMapCount].Length);
TRACE("Type: 0x%lx\n", PcBiosMemoryMap[PcBiosMapCount].Type);
TRACE("Reserved: 0x%lx\n", PcBiosMemoryMap[PcBiosMapCount].Reserved);
TRACE("\n");
/* Check if this is free memory */
if (PcBiosMemoryMap[PcBiosMapCount].Type == BiosMemoryUsable)
{
MemoryType = LoaderFree;
/* Align up base of memory area */
RealBaseAddress = PcBiosMemoryMap[PcBiosMapCount].BaseAddress & ~(MM_PAGE_SIZE - 1ULL);
/* Calculate the length after aligning the base */
RealSize = PcBiosMemoryMap[PcBiosMapCount].BaseAddress +
PcBiosMemoryMap[PcBiosMapCount].Length - RealBaseAddress;
RealSize = (RealSize + MM_PAGE_SIZE - 1) & ~(MM_PAGE_SIZE - 1ULL);
}
else
{
if (PcBiosMemoryMap[PcBiosMapCount].Type == BiosMemoryReserved)
MemoryType = LoaderFirmwarePermanent;
else
MemoryType = LoaderSpecialMemory;
/* Align down base of memory area */
RealBaseAddress = PcBiosMemoryMap[PcBiosMapCount].BaseAddress & ~(MM_PAGE_SIZE - 1ULL);
/* Calculate the length after aligning the base */
RealSize = PcBiosMemoryMap[PcBiosMapCount].BaseAddress +
PcBiosMemoryMap[PcBiosMapCount].Length - RealBaseAddress;
RealSize = (RealSize + MM_PAGE_SIZE - 1) & ~(MM_PAGE_SIZE - 1ULL);
}
/* Check if we can add this descriptor */
if ((RealSize >= MM_PAGE_SIZE) && (MapCount < MaxMemoryMapSize))
{
/* Add the descriptor */
MapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
(PFN_NUMBER)(RealBaseAddress / MM_PAGE_SIZE),
(PFN_NUMBER)(RealSize / MM_PAGE_SIZE),
MemoryType);
}
PcBiosMapCount++;
/* If the continuation value is zero or the
* carry flag is set then this was
* the last entry so we're done */
if (Regs.x.ebx == 0x00000000)
{
TRACE("End Of System Memory Map!\n\n");
break;
}
}
return MapCount;
}
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;
}
static
ULONG
PcMemGetBiosMemoryMap(PFREELDR_MEMORY_DESCRIPTOR MemoryMap, ULONG MaxMemoryMapSize)
{
REGS Regs;
ULONGLONG RealBaseAddress, EndAddress, RealSize;
TYPE_OF_MEMORY MemoryType;
ULONG Size, RequiredSize;
ASSERT(PcBiosMapCount == 0);
TRACE("GetBiosMemoryMap()\n");
/* Make sure the usable memory is large enough. To do this we check the 16
bit value at address 0x413 inside the BDA, which gives us the usable size
in KB */
Size = (*(PUSHORT)(ULONG_PTR)0x413) * 1024;
RequiredSize = FREELDR_BASE + FrLdrImageSize + PAGE_SIZE;
if (Size < RequiredSize)
{
FrLdrBugCheckWithMessage(
MEMORY_INIT_FAILURE,
__FILE__,
__LINE__,
"The BIOS reported a usable memory range up to 0x%x, which is too small!\n"
"Required size is 0x%x\n\n"
"If you see this, please report to the ReactOS team!",
Size, RequiredSize);
}
/* Int 15h AX=E820h
* Newer BIOSes - GET SYSTEM MEMORY MAP
*
* AX = E820h
* EAX = 0000E820h
* EDX = 534D4150h ('SMAP')
* EBX = continuation value or 00000000h to start at beginning of map
* ECX = size of buffer for result, in bytes (should be >= 20 bytes)
* ES:DI -> buffer for result
* Return:
* CF clear if successful
* EAX = 534D4150h ('SMAP')
* ES:DI buffer filled
* EBX = next offset from which to copy or 00000000h if all done
* ECX = actual length returned in bytes
* CF set on error
* AH = error code (86h)
*/
Regs.x.ebx = 0x00000000;
while (PcBiosMapCount < MAX_BIOS_DESCRIPTORS)
{
/* Setup the registers for the BIOS call */
Regs.x.eax = 0x0000E820;
Regs.x.edx = 0x534D4150; /* ('SMAP') */
/* Regs.x.ebx = 0x00000001; Continuation value already set */
Regs.x.ecx = sizeof(BIOS_MEMORY_MAP);
Regs.w.es = BIOSCALLBUFSEGMENT;
Regs.w.di = BIOSCALLBUFOFFSET;
Int386(0x15, &Regs, &Regs);
TRACE("Memory Map Entry %d\n", PcBiosMapCount);
TRACE("Int15h AX=E820h\n");
TRACE("EAX = 0x%x\n", Regs.x.eax);
TRACE("EBX = 0x%x\n", Regs.x.ebx);
TRACE("ECX = 0x%x\n", Regs.x.ecx);
TRACE("CF set = %s\n", (Regs.x.eflags & EFLAGS_CF) ? "TRUE" : "FALSE");
/* If the BIOS didn't return 'SMAP' in EAX then
* it doesn't support this call. If CF is set, we're done */
if (Regs.x.eax != 0x534D4150 || !INT386_SUCCESS(Regs))
{
break;
}
/* Copy data to global buffer */
RtlCopyMemory(&PcBiosMemoryMap[PcBiosMapCount], (PVOID)BIOSCALLBUFFER, Regs.x.ecx);
TRACE("BaseAddress: 0x%llx\n", PcBiosMemoryMap[PcBiosMapCount].BaseAddress);
TRACE("Length: 0x%llx\n", PcBiosMemoryMap[PcBiosMapCount].Length);
TRACE("Type: 0x%lx\n", PcBiosMemoryMap[PcBiosMapCount].Type);
TRACE("Reserved: 0x%lx\n", PcBiosMemoryMap[PcBiosMapCount].Reserved);
TRACE("\n");
/* Check if this is free memory */
if (PcBiosMemoryMap[PcBiosMapCount].Type == BiosMemoryUsable)
{
MemoryType = LoaderFree;
/* Align up base of memory range */
RealBaseAddress = ALIGN_UP_BY(PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
PAGE_SIZE);
/* Calculate aligned EndAddress */
EndAddress = PcBiosMemoryMap[PcBiosMapCount].BaseAddress +
PcBiosMemoryMap[PcBiosMapCount].Length;
EndAddress = ALIGN_DOWN_BY(EndAddress, PAGE_SIZE);
/* Check if there is anything left */
if (EndAddress <= RealBaseAddress)
{
/* This doesn't span any page, so continue with next range */
continue;
}
/* Calculate the length of the aligned range */
RealSize = EndAddress - RealBaseAddress;
}
else
{
if (PcBiosMemoryMap[PcBiosMapCount].Type == BiosMemoryReserved)
MemoryType = LoaderFirmwarePermanent;
else
MemoryType = LoaderSpecialMemory;
/* Align down base of memory area */
RealBaseAddress = ALIGN_DOWN_BY(PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
PAGE_SIZE);
/* Calculate the length after aligning the base */
RealSize = PcBiosMemoryMap[PcBiosMapCount].BaseAddress +
PcBiosMemoryMap[PcBiosMapCount].Length - RealBaseAddress;
RealSize = ALIGN_UP_BY(RealSize, PAGE_SIZE);
}
/* Check if we can add this descriptor */
if ((RealSize >= MM_PAGE_SIZE) && (PcMapCount < MaxMemoryMapSize))
{
/* Add the descriptor */
PcMapCount = AddMemoryDescriptor(PcMemoryMap,
MAX_BIOS_DESCRIPTORS,
(PFN_NUMBER)(RealBaseAddress / MM_PAGE_SIZE),
(PFN_NUMBER)(RealSize / MM_PAGE_SIZE),
MemoryType);
}
PcBiosMapCount++;
/* If the continuation value is zero or the
* carry flag is set then this was
* the last entry so we're done */
if (Regs.x.ebx == 0x00000000)
{
TRACE("End Of System Memory Map!\n\n");
break;
}
}
TRACE("GetBiosMemoryMap end, PcBiosMapCount = %ld\n", PcBiosMapCount);
return PcBiosMapCount;
}
