pcmem.c File Reference

#include <freeldr.h>
#include <arch/pc/x86common.h>
#include <debug.h>

Include dependency graph for pcmem.c:

Go to the source code of this file.

Macros
#define	ULONGLONG_ALIGN_DOWN_BY(size, align)    ((ULONGLONG)(size) & ~((ULONGLONG)(align) - 1))
#define	ULONGLONG_ALIGN_UP_BY(size, align)    (ULONGLONG_ALIGN_DOWN_BY(((ULONGLONG)(size) + align - 1), align))

Functions
	DBG_DEFAULT_CHANNEL (MEMORY)
ULONG	AddMemoryDescriptor (IN OUT PFREELDR_MEMORY_DESCRIPTOR List, IN ULONG MaxCount, IN PFN_NUMBER BasePage, IN PFN_NUMBER PageCount, IN TYPE_OF_MEMORY MemoryType)
static BOOLEAN	GetExtendedMemoryConfiguration (ULONG *pMemoryAtOneMB, ULONG *pMemoryAtSixteenMB)
static ULONG	PcMemGetConventionalMemorySize (VOID)
static BOOLEAN	GetEbdaLocation (PULONG BaseAddress, PULONG Size)
static VOID	PcMemCheckUsableMemorySize (VOID)
static ULONG	PcMemGetBiosMemoryMap (PFREELDR_MEMORY_DESCRIPTOR MemoryMap, ULONG MaxMemoryMapSize)
VOID	ReserveMemory (PFREELDR_MEMORY_DESCRIPTOR MemoryMap, ULONG_PTR BaseAddress, SIZE_T Size, TYPE_OF_MEMORY MemoryType, PCHAR Usage)
VOID	SetMemory (PFREELDR_MEMORY_DESCRIPTOR MemoryMap, ULONG_PTR BaseAddress, SIZE_T Size, TYPE_OF_MEMORY MemoryType)
ULONG	PcMemFinalizeMemoryMap (PFREELDR_MEMORY_DESCRIPTOR MemoryMap)
PFREELDR_MEMORY_DESCRIPTOR	PcMemGetMemoryMap (ULONG *MemoryMapSize)

Variables
BIOS_MEMORY_MAP	PcBiosMemoryMap [MAX_BIOS_DESCRIPTORS]
ULONG	PcBiosMapCount
FREELDR_MEMORY_DESCRIPTOR	PcMemoryMap [MAX_BIOS_DESCRIPTORS+1]
ULONG	PcMapCount

Macro Definition Documentation

ULONGLONG_ALIGN_DOWN_BY

#define ULONGLONG_ALIGN_DOWN_BY	(		size,
			align
	)		((ULONGLONG)(size) & ~((ULONGLONG)(align) - 1))

Definition at line 31 of file pcmem.c.

ULONGLONG_ALIGN_UP_BY

#define ULONGLONG_ALIGN_UP_BY	(		size,
			align
	)		(ULONGLONG_ALIGN_DOWN_BY(((ULONGLONG)(size) + align - 1), align))

Definition at line 34 of file pcmem.c.

Function Documentation

AddMemoryDescriptor()

ULONG AddMemoryDescriptor	(	IN OUT PFREELDR_MEMORY_DESCRIPTOR	List,
		IN ULONG	MaxCount,
		IN PFN_NUMBER	BasePage,
		IN PFN_NUMBER	PageCount,
		IN TYPE_OF_MEMORY	MemoryType
	)

Definition at line 123 of file meminit.c.

{
    ULONG Index, DescriptCount;
    PFN_NUMBER EndPage;
    TRACE("AddMemoryDescriptor(0x%Ix, 0x%Ix, %u)\n",
          BasePage, PageCount, MemoryType);
 
    EndPage = BasePage + PageCount;
 
    /* Skip over all descriptor below the new range */
    Index = 0;
    while ((List[Index].PageCount != 0) &&
           ((List[Index].BasePage + List[Index].PageCount) <= BasePage))
    {
        Index++;
    }
 
    /* Count the descriptors */
    DescriptCount = Index;
    while (List[DescriptCount].PageCount != 0)
    {
        DescriptCount++;
    }
 
    /* Check if the existing range conflicts with the new range */
    while ((List[Index].PageCount != 0) &&
           (List[Index].BasePage < EndPage))
    {
        TRACE("AddMemoryDescriptor conflict @%lu: new=[%lx:%lx], existing=[%lx,%lx]\n",
              Index, BasePage, PageCount, List[Index].BasePage, List[Index].PageCount);
 
        /*
         * We have 4 overlapping cases:
         *
         * Case              (a)       (b)       (c)       (d)
         * Existing range  |---|     |-----|    |---|      |---|
         * New range         |---|    |---|    |-----|   |---|
         *
         */
 
        /* Check if the existing range starts before the new range (a)/(b) */
        if (List[Index].BasePage < BasePage)
        {
            /* Check if the existing range extends beyond the new range (b) */
            if (List[Index].BasePage + List[Index].PageCount > EndPage)
            {
                /* Split the descriptor */
                RtlMoveMemory(&List[Index + 1],
                              &List[Index],
                              (DescriptCount - Index) * sizeof(List[0]));
                List[Index + 1].BasePage = EndPage;
                List[Index + 1].PageCount = List[Index].BasePage +
                                            List[Index].PageCount -
                                            List[Index + 1].BasePage;
                List[Index].PageCount = BasePage - List[Index].BasePage;
                Index++;
                DescriptCount++;
                break;
            }
            else
            {
                /* Crop the existing range and continue with the next range */
                List[Index].PageCount = BasePage - List[Index].BasePage;
                Index++;
            }
        }
        /* Check if the existing range is fully covered by the new range (c) */
        else if ((List[Index].BasePage + List[Index].PageCount) <=
                 EndPage)
        {
            /* Delete this descriptor */
            RtlMoveMemory(&List[Index],
                          &List[Index + 1],
                          (DescriptCount - Index) * sizeof(List[0]));
            DescriptCount--;
        }
        /* Otherwise the existing range ends after the new range (d) */
        else
        {
            /* Crop the existing range at the start and bail out */
            List[Index].PageCount -= EndPage - List[Index].BasePage;
            List[Index].BasePage = EndPage;
            break;
        }
    }
 
    /* Make sure we can still add a new descriptor */
    if (DescriptCount >= MaxCount)
    {
        FrLdrBugCheckWithMessage(
            MEMORY_INIT_FAILURE,
            __FILE__,
            __LINE__,
            "Ran out of static memory descriptors!");
    }
 
    /* Insert the new descriptor */
    if (Index < DescriptCount)
    {
        RtlMoveMemory(&List[Index + 1],
                      &List[Index],
                      (DescriptCount - Index) * sizeof(List[0]));
    }
 
    List[Index].BasePage = BasePage;
    List[Index].PageCount = PageCount;
    List[Index].MemoryType = MemoryType;
    DescriptCount++;
 
#if 0 // only enable on demand!
    DbgDumpMemoryMap(List);
#endif
    return DescriptCount;
}

Referenced by PcMemGetBiosMemoryMap(), PcMemGetMemoryMap(), ReserveMemory(), and SetMemory().

DBG_DEFAULT_CHANNEL()

DBG_DEFAULT_CHANNEL

(

MEMORY

)

GetEbdaLocation()

static BOOLEAN GetEbdaLocation ( PULONG  BaseAddress, PULONG  Size  )

static

Definition at line 175 of file pcmem.c.

{
    REGS Regs;
 
    TRACE("GetEbdaLocation()\n");
 
    /* 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))
    {
        return FALSE;
    }
 
    /* Get Base address and (maximum) size */
    *BaseAddress = (ULONG)Regs.w.es << 4;
    *Size = 0xA0000 - *BaseAddress;
    return TRUE;
}

Referenced by PcMemGetMemoryMap().

GetExtendedMemoryConfiguration()

static BOOLEAN GetExtendedMemoryConfiguration ( ULONG *  pMemoryAtOneMB, ULONG *  pMemoryAtSixteenMB  )

static

Definition at line 53 of file pcmem.c.

{
    REGS     RegsIn;
    REGS     RegsOut;
 
    TRACE("GetExtendedMemoryConfiguration()\n");
 
    *pMemoryAtOneMB = 0;
    *pMemoryAtSixteenMB = 0;
 
    // Int 15h AX=E801h
    // Phoenix BIOS v4.0 - GET MEMORY SIZE FOR >64M CONFIGURATIONS
    //
    // AX = E801h
    // Return:
    // CF clear if successful
    // AX = extended memory between 1M and 16M, in K (max 3C00h = 15MB)
    // BX = extended memory above 16M, in 64K blocks
    // CX = configured memory 1M to 16M, in K
    // DX = configured memory above 16M, in 64K blocks
    // CF set on error
    RegsIn.w.ax = 0xE801;
    Int386(0x15, &RegsIn, &RegsOut);
 
    TRACE("Int15h AX=E801h\n");
    TRACE("AX = 0x%x\n", RegsOut.w.ax);
    TRACE("BX = 0x%x\n", RegsOut.w.bx);
    TRACE("CX = 0x%x\n", RegsOut.w.cx);
    TRACE("DX = 0x%x\n", RegsOut.w.dx);
    TRACE("CF set = %s\n", (RegsOut.x.eflags & EFLAGS_CF) ? "TRUE" : "FALSE");
 
    if (INT386_SUCCESS(RegsOut))
    {
        // If AX=BX=0000h the use CX and DX
        if (RegsOut.w.ax == 0)
        {
            // Return extended memory size in K
            *pMemoryAtSixteenMB = RegsOut.w.dx;
            *pMemoryAtOneMB = RegsOut.w.cx;
            return TRUE;
        }
        else
        {
            // Return extended memory size in K
            *pMemoryAtSixteenMB = RegsOut.w.bx;
            *pMemoryAtOneMB = RegsOut.w.ax;
            return TRUE;
        }
    }
 
    // If we get here then Int15 Func E801h didn't work
    // So try Int15 Func 88h
    // Int 15h AH=88h
    // SYSTEM - GET EXTENDED MEMORY SIZE (286+)
    //
    // AH = 88h
    // Return:
    // CF clear if successful
    // AX = number of contiguous KB starting at absolute address 100000h
    // CF set on error
    // AH = status
    // 80h invalid command (PC,PCjr)
    // 86h unsupported function (XT,PS30)
    RegsIn.b.ah = 0x88;
    Int386(0x15, &RegsIn, &RegsOut);
 
    TRACE("Int15h AH=88h\n");
    TRACE("AX = 0x%x\n", RegsOut.w.ax);
    TRACE("CF set = %s\n", (RegsOut.x.eflags & EFLAGS_CF) ? "TRUE" : "FALSE");
 
    if (INT386_SUCCESS(RegsOut) && RegsOut.w.ax != 0)
    {
        *pMemoryAtOneMB = RegsOut.w.ax;
        return TRUE;
    }
 
    // If we get here then Int15 Func 88h didn't work
    // So try reading the CMOS
    WRITE_PORT_UCHAR((PUCHAR)0x70, 0x31);
    *pMemoryAtOneMB = READ_PORT_UCHAR((PUCHAR)0x71);
    *pMemoryAtOneMB = (*pMemoryAtOneMB & 0xFFFF);
    *pMemoryAtOneMB = (*pMemoryAtOneMB << 8);
 
    TRACE("Int15h Failed\n");
    TRACE("CMOS reports: 0x%lx\n", *pMemoryAtOneMB);
 
    if (*pMemoryAtOneMB != 0)
    {
        return TRUE;
    }
 
    return FALSE;
}

Referenced by PcMemGetMemoryMap().

PcMemCheckUsableMemorySize()

static VOID PcMemCheckUsableMemorySize ( VOID  )

static

Definition at line 209 of file pcmem.c.

{
    ULONG Size, RequiredSize;
 
    TRACE("PcMemCheckUsableMemorySize()\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%lx, which is too small!\n"
            "Required size is 0x%lx\n\n"
            "If you see this, please report to the ReactOS team!",
            Size, RequiredSize);
    }
}

Referenced by PcMemGetMemoryMap().

PcMemFinalizeMemoryMap()

ULONG PcMemFinalizeMemoryMap

(

PFREELDR_MEMORY_DESCRIPTOR

MemoryMap

)

Definition at line 547 of file pcmem.c.

{
    ULONG i;
 
    /* Reserve some static ranges for freeldr */
    ReserveMemory(MemoryMap, 0x1000, STACKLOW - 0x1000, LoaderFirmwareTemporary, "BIOS area");
    ReserveMemory(MemoryMap, STACKLOW, STACKADDR - STACKLOW, LoaderOsloaderStack, "FreeLdr stack");
    ReserveMemory(MemoryMap, 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 ((MemoryMap[i].BasePage > (FREELDR_BASE / PAGE_SIZE)) &&
            (MemoryMap[i].MemoryType == LoaderFree))
        {
            /* Use this range for the disk read buffer */
            DiskReadBuffer = (PVOID)(MemoryMap[i].BasePage * PAGE_SIZE);
            DiskReadBufferSize = min(MemoryMap[i].PageCount * PAGE_SIZE,
                                     MAX_DISKREADBUFFER_SIZE);
            break;
        }
    }
 
    TRACE("DiskReadBuffer=0x%p, DiskReadBufferSize=0x%lx\n",
          DiskReadBuffer, DiskReadBufferSize);
 
    ASSERT(DiskReadBufferSize > 0);
 
    /* Now reserve the range for the disk read buffer */
    ReserveMemory(MemoryMap,
                  (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",
              MemoryMap[i].BasePage,
              MemoryMap[i].PageCount,
              MmGetSystemMemoryMapTypeString(MemoryMap[i].MemoryType));
    }
    return PcMapCount;
}

Referenced by Pc98MemGetMemoryMap(), PcMemGetMemoryMap(), and XboxMemGetMemoryMap().

PcMemGetBiosMemoryMap()

static ULONG PcMemGetBiosMemoryMap ( PFREELDR_MEMORY_DESCRIPTOR  MemoryMap, ULONG  MaxMemoryMapSize  )

static

Definition at line 235 of file pcmem.c.

{
    REGS Regs;
    ULONGLONG RealBaseAddress, EndAddress, RealSize;
    TYPE_OF_MEMORY MemoryType;
 
    ASSERT(PcBiosMapCount == 0);
 
    TRACE("PcMemGetBiosMemoryMap()\n");
 
    /* 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)
    {
        /* ACPI 3.0/4.0: Set Extended Attributes to enabled/valid by default, in case entry has no E.A.. */
        ((PBIOS_MEMORY_MAP)BIOSCALLBUFFER)->ExtendedAttributesAsULONG = 0;
        ((PBIOS_MEMORY_MAP)BIOSCALLBUFFER)->ExtendedAttributes.Enabled_Reserved = 1;
 
        /* 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 %lu\n", PcBiosMapCount);
        TRACE("Int15h AX=E820h\n");
        TRACE("EAX = 0x%lx\n", Regs.x.eax);
        TRACE("EBX = 0x%lx\n", Regs.x.ebx);
        TRACE("ECX = %lu\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 (Regs.x.eax != 0x534D4150)
        {
            WARN("BIOS doesn't support Int15h AX=E820h!\n");
            break;
        }
 
        /* If the carry flag is set,
         * then this call was past the last entry, so we're done. */
        if (!INT386_SUCCESS(Regs))
        {
            TRACE("End of System Memory Map! (Past last)\n");
            break;
        }
 
        if (Regs.x.ecx == 0)
        {
            TRACE("Discarding empty entry. (would-be-PcBiosMapCount = %lu)\n",
                  PcBiosMapCount);
            goto nextRange;
        }
 
        /* Extra safety: unexpected entry length.
         * All in-between values are valid too, as x86 is little-indian
         * and only lower byte is used per ACPI 6.2-A.
         */
        if (Regs.x.ecx < RTL_SIZEOF_THROUGH_FIELD(BIOS_MEMORY_MAP, Type) ||
            Regs.x.ecx > sizeof(BIOS_MEMORY_MAP))
        {
            ERR("Int 15h AX=E820h returned an invalid entry length! (would-be-PcBiosMapCount = %lu, Entry length = (%Iu <=) %lu (<= %Iu))\n",
                PcBiosMapCount, RTL_SIZEOF_THROUGH_FIELD(BIOS_MEMORY_MAP, Type), Regs.x.ecx, sizeof(BIOS_MEMORY_MAP));
            /* Warn user, unless wrong case is "first and not too big entry", which is otherwise harmless. */
            if (PcBiosMapCount > 0 || Regs.x.ecx > sizeof(BIOS_MEMORY_MAP))
            {
                ASSERTMSG("Int 15h AX=E820h returned an invalid entry length!\n", FALSE);
            }
            /* We keep previous entries (if any), but do not dare trying next entries.
             * We assume these entries are good to use as is. If they are not, we are in trouble...
             * (And don't ask what happens if BIOS actually overflowed our entry buffer...)
             *
             * FIXME: Safer = revert previous entries, Safest = blacklist this BIOS.
             */
            break;
        }
 
        if (((PBIOS_MEMORY_MAP)BIOSCALLBUFFER)->ExtendedAttributes.Enabled_Reserved == 0)
        {
            WARN("Discarding disabled/invalid entry. (would-be-PcBiosMapCount = %lu)\n",
                 PcBiosMapCount);
            /* This unlikely case was correct between ACPI 3.0 and 4.0, so assume all is fine.
             * Unless we would be ready to drop ACPI 3.0 compatibility.
             */
            goto nextRange;
        }
 
        /*
         * Other deprecated ExtendedAttributes flags such as NonVolatile_Deprecated_Reserved
         * or SlowAccess_Deprecated_Reserved are simply ignored.
         */
 
        /* Copy data to global buffer */
        RtlCopyMemory(&PcBiosMemoryMap[PcBiosMapCount], (PVOID)BIOSCALLBUFFER, sizeof(BIOS_MEMORY_MAP));
 
        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("ExtendedAttributesAsULONG: 0x%08lx\n", PcBiosMemoryMap[PcBiosMapCount].ExtendedAttributesAsULONG);
 
        if (PcBiosMemoryMap[PcBiosMapCount].ExtendedAttributes.ErrorLog == 1)
        {
            FIXME("EA.ErrorLog = 1. Please report this to CORE-14150. "
                   "(PcBiosMapCount = %lu, BaseAddress = 0x%llx, Length = 0x%llx, Type = 0x%lx, ExtendedAttributesAsULONG = 0x%08lx)\n",
                  PcBiosMapCount,
                  PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
                  PcBiosMemoryMap[PcBiosMapCount].Length,
                  PcBiosMemoryMap[PcBiosMapCount].Type,
                  PcBiosMemoryMap[PcBiosMapCount].ExtendedAttributesAsULONG);
            // NotWantedForPublicBuilds: ASSERTMSG("EA.ErrorLog = 1. Check/Report then CONTinue.\n", FALSE);
        }
 
        if (PcBiosMemoryMap[PcBiosMapCount].Length == 0)
        {
            TRACE("Discarding empty range. (would-be-PcBiosMapCount = %lu, BaseAddress = 0x%llx, Length = 0)\n",
                  PcBiosMapCount, PcBiosMemoryMap[PcBiosMapCount].BaseAddress);
            goto nextRange;
        }
 
        /* Check if this is free memory */
        if (PcBiosMemoryMap[PcBiosMapCount].Type == BiosMemoryUsable)
        {
            MemoryType = LoaderFree;
 
            /* Align up base of memory range */
            RealBaseAddress = ULONGLONG_ALIGN_UP_BY(
                                PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
                                PAGE_SIZE);
 
            /* Calculate aligned EndAddress */
            EndAddress = PcBiosMemoryMap[PcBiosMapCount].BaseAddress +
                         PcBiosMemoryMap[PcBiosMapCount].Length;
            EndAddress = ULONGLONG_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 */
                TRACE("Skipping aligned range < PAGE_SIZE. (would-be-PcBiosMapCount = %lu, BaseAddress = 0x%llx, Length = 0x%llx)\n",
                      PcBiosMapCount,
                      PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
                      PcBiosMemoryMap[PcBiosMapCount].Length);
                goto nextRange;
            }
 
            /* 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 = ULONGLONG_ALIGN_DOWN_BY(
                                PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
                                PAGE_SIZE);
 
            /* Calculate the length after aligning the base */
            RealSize = PcBiosMemoryMap[PcBiosMapCount].BaseAddress +
                       PcBiosMemoryMap[PcBiosMapCount].Length - RealBaseAddress;
            RealSize = ULONGLONG_ALIGN_UP_BY(RealSize, PAGE_SIZE);
        }
 
        /* Check if we can add this descriptor */
        if (RealSize < MM_PAGE_SIZE)
        {
            TRACE("Skipping aligned range < MM_PAGE_SIZE. (PcBiosMapCount = %lu, BaseAddress = 0x%llx, Length = 0x%llx)\n",
                  PcBiosMapCount,
                  PcBiosMemoryMap[PcBiosMapCount].BaseAddress,
                  PcBiosMemoryMap[PcBiosMapCount].Length);
        }
        else if (PcMapCount >= MaxMemoryMapSize)
        {
            ERR("PcMemoryMap is already full! (PcBiosMapCount = %lu, PcMapCount = %lu (>= %lu))\n",
                PcBiosMapCount, PcMapCount, MaxMemoryMapSize);
            // NotWantedForPublicBuilds: ASSERTMSG("PcMemoryMap is already full!\n", FALSE);
            /* We keep previous entries, and half-retrieve current/next entries.
             * We assume all these entries are good to use as is. If they are not, we are in trouble...
             *
             * FIXME: Safer = revert (half-)retrieved entries, Safest = increase MaxMemoryMapSize.
             */
        }
        else
        {
            /* Add the descriptor */
            PcMapCount = AddMemoryDescriptor(PcMemoryMap,
                                           MAX_BIOS_DESCRIPTORS,
                                           (PFN_NUMBER)(RealBaseAddress / MM_PAGE_SIZE),
                                           (PFN_NUMBER)(RealSize / MM_PAGE_SIZE),
                                           MemoryType);
        }
 
        PcBiosMapCount++;
 
nextRange:
        /* If the continuation value is zero,
         * then this was the last entry, so we're done. */
        if (Regs.x.ebx == 0x00000000)
        {
            TRACE("End of System Memory Map! (Reset)\n");
            break;
        }
    }
    /* Check whether there would be more entries to process. */
    if (PcBiosMapCount >= MAX_BIOS_DESCRIPTORS && Regs.x.ebx != 0x00000000)
    {
        ERR("PcBiosMemoryMap is already full! (PcBiosMapCount = %lu (>= %lu), PcMapCount = %lu)\n",
            PcBiosMapCount, MAX_BIOS_DESCRIPTORS, PcMapCount);
        // NotWantedForPublicBuilds: ASSERTMSG("PcBiosMemoryMap is already full!\n", FALSE);
        /* We keep retrieved entries, but ignore next entries.
         * We assume these entries are good to use as is. If they are not, we are in trouble...
         *
         * FIXME: Safer = revert retrieved entries, Safest = increase MAX_BIOS_DESCRIPTORS.
         */
    }
 
    TRACE("PcMemGetBiosMemoryMap end: PcBiosMapCount = %lu\n", PcBiosMapCount);
    return PcBiosMapCount;
}

Referenced by PcMemGetMemoryMap().

PcMemGetConventionalMemorySize()

static ULONG PcMemGetConventionalMemorySize ( VOID  )

static

Definition at line 149 of file pcmem.c.

{
    REGS Regs;
 
    TRACE("PcMemGetConventionalMemorySize()\n");
 
    /* Int 12h
     * BIOS - GET MEMORY SIZE
     *
     * Return:
     * AX = kilobytes of contiguous memory starting at absolute address 00000h
     *
     * This call returns the contents of the word at 0040h:0013h;
     * in PC and XT, this value is set from the switches on the motherboard
     */
    Regs.w.ax = 0;
    Int386(0x12, &Regs, &Regs);
 
    TRACE("Int12h\n");
    TRACE("AX = 0x%x\n", Regs.w.ax);
 
    return (ULONG)Regs.w.ax;
}

Referenced by PcMemGetMemoryMap().

PcMemGetMemoryMap()

PFREELDR_MEMORY_DESCRIPTOR PcMemGetMemoryMap

(

ULONG *

MemoryMapSize

)

Definition at line 599 of file pcmem.c.

{
    ULONG EntryCount;
    ULONG ExtendedMemorySizeAtOneMB;
    ULONG ExtendedMemorySizeAtSixteenMB;
    ULONG EbdaBase, EbdaSize;
 
    TRACE("PcMemGetMemoryMap()\n");
 
    PcMemCheckUsableMemorySize();
 
    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(PcMemoryMap, 0x000000, 0x01000, LoaderFirmwarePermanent); // Realmode IVT / BDA
    SetMemory(PcMemoryMap, 0x0A0000, 0x50000, LoaderFirmwarePermanent); // Video memory
    SetMemory(PcMemoryMap, 0x0F0000, 0x10000, LoaderSpecialMemory); // ROM
    SetMemory(PcMemoryMap, 0xFFF000, 0x01000, LoaderSpecialMemory); // unusable memory (do we really need this?)
 
    *MemoryMapSize = PcMemFinalizeMemoryMap(PcMemoryMap);
    return PcMemoryMap;
}

Referenced by MachInit().

ReserveMemory()

VOID ReserveMemory	(	PFREELDR_MEMORY_DESCRIPTOR	MemoryMap,
		ULONG_PTR	BaseAddress,
		SIZE_T	Size,
		TYPE_OF_MEMORY	MemoryType,
		PCHAR	Usage
	)

Definition at line 484 of file pcmem.c.

{
    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 ((MemoryMap[i].BasePage < BasePage + PageCount) &&
            (MemoryMap[i].BasePage + MemoryMap[i].PageCount > BasePage))
        {
            /* Check if the memory is free */
            if (MemoryMap[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(MemoryMap,
                                     MAX_BIOS_DESCRIPTORS,
                                     BasePage,
                                     PageCount,
                                     MemoryType);
}

Referenced by PcMemFinalizeMemoryMap(), and XboxMemGetMemoryMap().

SetMemory()

VOID SetMemory	(	PFREELDR_MEMORY_DESCRIPTOR	MemoryMap,
		ULONG_PTR	BaseAddress,
		SIZE_T	Size,
		TYPE_OF_MEMORY	MemoryType
	)

Definition at line 527 of file pcmem.c.

{
    ULONG_PTR BasePage, PageCount;
 
    BasePage = BaseAddress / PAGE_SIZE;
    PageCount = ADDRESS_AND_SIZE_TO_SPAN_PAGES(BaseAddress, Size);
 
    /* Add the memory descriptor */
    PcMapCount = AddMemoryDescriptor(MemoryMap,
                                     MAX_BIOS_DESCRIPTORS,
                                     BasePage,
                                     PageCount,
                                     MemoryType);
}

Referenced by Pc98MemGetMemoryMap(), PcMemGetMemoryMap(), and XboxMemGetMemoryMap().

Variable Documentation

PcBiosMapCount

ULONG PcBiosMapCount

Definition at line 38 of file pcmem.c.

Referenced by DetectAcpiBios(), Pc98MemGetMemoryMap(), and PcMemGetBiosMemoryMap().

PcBiosMemoryMap

BIOS_MEMORY_MAP PcBiosMemoryMap[MAX_BIOS_DESCRIPTORS]

Definition at line 37 of file pcmem.c.

Referenced by DetectAcpiBios(), Pc98MemGetMemoryMap(), and PcMemGetBiosMemoryMap().

PcMapCount

ULONG PcMapCount

Definition at line 41 of file pcmem.c.

Referenced by PcMemFinalizeMemoryMap(), PcMemGetBiosMemoryMap(), PcMemGetMemoryMap(), ReserveMemory(), and SetMemory().

PcMemoryMap

FREELDR_MEMORY_DESCRIPTOR PcMemoryMap[MAX_BIOS_DESCRIPTORS+1]

Definition at line 40 of file pcmem.c.

Referenced by PcMemGetBiosMemoryMap(), and PcMemGetMemoryMap().