This commit was generated by cvs2svn to compensate for changes in r131440,

which included commits to RCS files with non-trunk default branches.

10 files changed, 165 insertions, 72 deletions

diff --git a/sys/contrib/dev/acpica/CHANGES.txt b/sys/contrib/dev/acpica/CHANGES.txt
index 9e71afc..81ac58d 100644
--- a/sys/contrib/dev/acpica/CHANGES.txt
+++ b/sys/contrib/dev/acpica/CHANGES.txt
@@ -1,4 +1,51 @@
 ----------------------------------------
+27 May 2004.  Summary of changes for version 20040527:
+
+1) ACPI CA Core Subsystem:
+
+Completed a new design and implementation for EBDA (Extended BIOS
+Data Area) support in the RSDP scan code.  The original code
+improperly scanned for the EBDA by simply scanning from memory
+location 0 to 0x400.  The correct method is to first obtain the
+EBDA pointer from within the BIOS data area, then scan 1K of
+memory starting at the EBDA pointer.  There appear to be few if
+any machines that place the RSDP in the EBDA, however.
+
+Integrated a fix for a possible fault during evaluation of
+BufferField arguments.  Obsolete code that was causing the
+problem was removed.
+
+Found and fixed a problem in the Field Support Code where data
+could be corrupted on a bit field read that starts on an aligned
+boundary but does not end on an aligned boundary.  Merged the
+read/write "datum length" calculation code into a common
+procedure.
+
+Rolled in a couple of changes to the FreeBSD-specific header.
+
+Code and Data Size: Current and previous core subsystem library
+sizes are shown below.  These are the code and data sizes for the
+acpica.lib produced by the Microsoft Visual C++ 6.0 compiler, and
+these values do not include any ACPI driver or OSPM code.  The
+debug version of the code includes the debug output trace
+mechanism and has a much larger code and data size.  Note that
+these values will vary depending on the efficiency of the
+compiler and the compiler options used during generation.
+
+  Previous Release:
+    Non-Debug Version:  77.6K Code,  11.5K Data,   89.1K Total
+    Debug Version:     163.2K Code,  67.2K Data,  230.4K Total
+  Current Release:
+    Non-Debug Version:  77.7K Code,  11.5K Data,   89.2K Total
+    Debug Version:     163.3K Code,  67.2K Data,  230.5K Total
+
+
+2) iASL Compiler/Disassembler:
+
+Fixed a generation warning produced by some overly-verbose
+compilers for a 64-bit constant.
+
+----------------------------------------
 14 May 2004.  Summary of changes for version 20040514:
 
 1) ACPI CA Core Subsystem:
diff --git a/sys/contrib/dev/acpica/acinterp.h b/sys/contrib/dev/acpica/acinterp.h
index a0f19a1..29ef907 100644
--- a/sys/contrib/dev/acpica/acinterp.h
+++ b/sys/contrib/dev/acpica/acinterp.h
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Name: acinterp.h - Interpreter subcomponent prototypes and defines
- *       $Revision: 148 $
+ *       $Revision: 149 $
  *
  *****************************************************************************/
 
@@ -191,6 +191,12 @@ AcpiExConvertToAscii (
  */
 
 ACPI_STATUS
+AcpiExCommonBufferSetup (
+    ACPI_OPERAND_OBJECT     *ObjDesc,
+    UINT32                  BufferLength,
+    UINT32                  *DatumCount);
+
+ACPI_STATUS
 AcpiExExtractFromField (
     ACPI_OPERAND_OBJECT     *ObjDesc,
     void                    *Buffer,
diff --git a/sys/contrib/dev/acpica/acmacros.h b/sys/contrib/dev/acpica/acmacros.h
index 9f577d6..6eb509d 100644
--- a/sys/contrib/dev/acpica/acmacros.h
+++ b/sys/contrib/dev/acpica/acmacros.h
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Name: acmacros.h - C macros for the entire subsystem.
- *       $Revision: 150 $
+ *       $Revision: 151 $
  *
  *****************************************************************************/
 
@@ -126,6 +126,9 @@
 #define ACPI_LOBYTE(l)                  ((UINT8)(UINT16)(l))
 #define ACPI_HIBYTE(l)                  ((UINT8)((((UINT16)(l)) >> 8) & 0xFF))
 
+#define ACPI_SET_BIT(target,bit)        ((target) |= (bit))
+#define ACPI_CLEAR_BIT(target,bit)      ((target) &= ~(bit))
+
 
 #if ACPI_MACHINE_WIDTH == 16
 
diff --git a/sys/contrib/dev/acpica/compiler/aslcompiler.y b/sys/contrib/dev/acpica/compiler/aslcompiler.y
index 18fe3af..a3cbf5a 100644
--- a/sys/contrib/dev/acpica/compiler/aslcompiler.y
+++ b/sys/contrib/dev/acpica/compiler/aslcompiler.y
@@ -2252,7 +2252,7 @@ QWordConstExpr
 ConstExprTerm
     : PARSEOP_ZERO                  {$$ = TrCreateValuedLeafNode (PARSEOP_ZERO, 0);}
     | PARSEOP_ONE                   {$$ = TrCreateValuedLeafNode (PARSEOP_ONE, 1);}
-    | PARSEOP_ONES                  {$$ = TrCreateValuedLeafNode (PARSEOP_ONES, 0xFFFFFFFFFFFFFFFFull);}
+    | PARSEOP_ONES                  {$$ = TrCreateValuedLeafNode (PARSEOP_ONES, ACPI_INTEGER_MAX);}
     ;
 
 /* OptionalCount must appear before ByteList or an incorrect reduction will result */
diff --git a/sys/contrib/dev/acpica/dbdisply.c b/sys/contrib/dev/acpica/dbdisply.c
index 0dd6396..38476f2 100644
--- a/sys/contrib/dev/acpica/dbdisply.c
+++ b/sys/contrib/dev/acpica/dbdisply.c
@@ -1,7 +1,7 @@
 /*******************************************************************************
  *
  * Module Name: dbdisply - debug display commands
- *              $Revision: 105 $
+ *              $Revision: 106 $
  *
  ******************************************************************************/
 
@@ -824,8 +824,8 @@ AcpiDbDisplayGpes (void)
                         (GpeBlock->RegisterCount * 8) -1);
             AcpiOsPrintf ("    RegisterInfo: %p  Status %8.8X%8.8X Enable %8.8X%8.8X\n",
                     GpeBlock->RegisterInfo,
-                    ACPI_FORMAT_UINT64 (GpeBlock->RegisterInfo->StatusAddress.Address),
-                    ACPI_FORMAT_UINT64 (GpeBlock->RegisterInfo->EnableAddress.Address));
+                    ACPI_FORMAT_UINT64 (ACPI_GET_ADDRESS (GpeBlock->RegisterInfo->StatusAddress.Address)),
+                    ACPI_FORMAT_UINT64 (ACPI_GET_ADDRESS (GpeBlock->RegisterInfo->EnableAddress.Address)));
             AcpiOsPrintf ("    EventInfo:    %p\n", GpeBlock->EventInfo);
 
             /* Examine each GPE Register within the block */
@@ -838,8 +838,8 @@ AcpiDbDisplayGpes (void)
                         "    Reg %u:  WakeEnable %2.2X, RunEnable %2.2X  Status %8.8X%8.8X Enable %8.8X%8.8X\n",
                         i, GpeRegisterInfo->EnableForWake,
                         GpeRegisterInfo->EnableForRun,
-                        ACPI_FORMAT_UINT64 (GpeRegisterInfo->StatusAddress.Address),
-                        ACPI_FORMAT_UINT64 (GpeRegisterInfo->EnableAddress.Address));
+                        ACPI_FORMAT_UINT64 (ACPI_GET_ADDRESS (GpeRegisterInfo->StatusAddress.Address)),
+                        ACPI_FORMAT_UINT64 (ACPI_GET_ADDRESS (GpeRegisterInfo->EnableAddress.Address)));
 
                 /* Now look at the individual GPEs in this byte register */
 
diff --git a/sys/contrib/dev/acpica/dsopcode.c b/sys/contrib/dev/acpica/dsopcode.c
index 5ccabb6..6a69e4a 100644
--- a/sys/contrib/dev/acpica/dsopcode.c
+++ b/sys/contrib/dev/acpica/dsopcode.c
@@ -2,7 +2,7 @@
  *
  * Module Name: dsopcode - Dispatcher Op Region support and handling of
  *                         "control" opcodes
- *              $Revision: 94 $
+ *              $Revision: 95 $
  *
  *****************************************************************************/
 
@@ -153,7 +153,6 @@ AcpiDsExecuteArguments (
     ACPI_STATUS             Status;
     ACPI_PARSE_OBJECT       *Op;
     ACPI_WALK_STATE         *WalkState;
-    ACPI_PARSE_OBJECT       *Arg;
 
 
     ACPI_FUNCTION_TRACE ("DsExecuteArguments");
@@ -204,9 +203,7 @@ AcpiDsExecuteArguments (
 
     /* Get and init the Op created above */
 
-    Arg = Op->Common.Value.Arg;
     Op->Common.Node = Node;
-    Arg->Common.Node = Node;
     AcpiPsDeleteParseTree (Op);
 
     /* Evaluate the deferred arguments */
diff --git a/sys/contrib/dev/acpica/evgpe.c b/sys/contrib/dev/acpica/evgpe.c
index 77ac5cd..f191d44 100644
--- a/sys/contrib/dev/acpica/evgpe.c
+++ b/sys/contrib/dev/acpica/evgpe.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Module Name: evgpe - General Purpose Event handling and dispatch
- *              $Revision: 40 $
+ *              $Revision: 42 $
  *
  *****************************************************************************/
 
@@ -206,28 +206,28 @@ AcpiEvUpdateGpeEnableMasks (
 
     if (Type == ACPI_GPE_DISABLE)
     {
-        GpeRegisterInfo->EnableForWake &= ~RegisterBit;
-        GpeRegisterInfo->EnableForRun  &= ~RegisterBit;
+        ACPI_CLEAR_BIT (GpeRegisterInfo->EnableForWake, RegisterBit);
+        ACPI_CLEAR_BIT (GpeRegisterInfo->EnableForRun, RegisterBit);
         return_ACPI_STATUS (AE_OK);
     }
 
-    /* 2) Enable case.  Set the appropriate enable bits */
+    /* 2) Enable case.  Set/Clear the appropriate enable bits */
 
     switch (GpeEventInfo->Flags & ACPI_GPE_TYPE_MASK)
     {
     case ACPI_GPE_TYPE_WAKE:
-        GpeRegisterInfo->EnableForWake |= RegisterBit;
-        GpeRegisterInfo->EnableForRun  &= ~RegisterBit;
+        ACPI_SET_BIT   (GpeRegisterInfo->EnableForWake, RegisterBit);
+        ACPI_CLEAR_BIT (GpeRegisterInfo->EnableForRun, RegisterBit);
         break;
 
     case ACPI_GPE_TYPE_RUNTIME:
-        GpeRegisterInfo->EnableForWake &= ~RegisterBit;
-        GpeRegisterInfo->EnableForRun  |= RegisterBit;
+        ACPI_CLEAR_BIT (GpeRegisterInfo->EnableForWake, RegisterBit);
+        ACPI_SET_BIT   (GpeRegisterInfo->EnableForRun, RegisterBit);
         break;
 
     case ACPI_GPE_TYPE_WAKE_RUN:
-        GpeRegisterInfo->EnableForWake |= RegisterBit;
-        GpeRegisterInfo->EnableForRun  |= RegisterBit;
+        ACPI_SET_BIT   (GpeRegisterInfo->EnableForWake, RegisterBit);
+        ACPI_SET_BIT   (GpeRegisterInfo->EnableForRun, RegisterBit);
         break;
 
     default:
@@ -274,17 +274,19 @@ AcpiEvEnableGpe (
     switch (GpeEventInfo->Flags & ACPI_GPE_TYPE_MASK)
     {
     case ACPI_GPE_TYPE_WAKE:
-        GpeEventInfo->Flags |= ACPI_GPE_WAKE_ENABLED;
+
+        ACPI_SET_BIT (GpeEventInfo->Flags, ACPI_GPE_WAKE_ENABLED);
         break;
 
     case ACPI_GPE_TYPE_WAKE_RUN:
-        GpeEventInfo->Flags |= ACPI_GPE_WAKE_ENABLED;
+
+        ACPI_SET_BIT (GpeEventInfo->Flags, ACPI_GPE_WAKE_ENABLED);
 
         /*lint -fallthrough */
 
     case ACPI_GPE_TYPE_RUNTIME:
 
-        GpeEventInfo->Flags |= ACPI_GPE_RUN_ENABLED;
+        ACPI_SET_BIT (GpeEventInfo->Flags, ACPI_GPE_RUN_ENABLED);
 
         if (WriteToHardware)
         {
@@ -350,11 +352,11 @@ AcpiEvDisableGpe (
     switch (GpeEventInfo->Flags & ACPI_GPE_TYPE_MASK)
     {
     case ACPI_GPE_TYPE_WAKE:
-        GpeEventInfo->Flags &= ~ACPI_GPE_WAKE_ENABLED;
+        ACPI_CLEAR_BIT (GpeEventInfo->Flags, ACPI_GPE_WAKE_ENABLED);
         break;
 
     case ACPI_GPE_TYPE_WAKE_RUN:
-        GpeEventInfo->Flags &= ~ACPI_GPE_WAKE_ENABLED;
+        ACPI_CLEAR_BIT (GpeEventInfo->Flags, ACPI_GPE_WAKE_ENABLED);
 
         /*lint -fallthrough */
 
@@ -362,7 +364,7 @@ AcpiEvDisableGpe (
 
         /* Disable the requested runtime GPE */
 
-        GpeEventInfo->Flags &= ~ACPI_GPE_RUN_ENABLED;
+        ACPI_CLEAR_BIT (GpeEventInfo->Flags, ACPI_GPE_RUN_ENABLED);
         Status = AcpiHwWriteGpeEnableReg (GpeEventInfo);
         break;
 
@@ -721,11 +723,11 @@ AcpiEvGpeDispatch (
 
     if (AcpiGbl_SystemAwakeAndRunning)
     {
-        GpeEventInfo->Flags |= ACPI_GPE_SYSTEM_RUNNING;
+        ACPI_SET_BIT (GpeEventInfo->Flags, ACPI_GPE_SYSTEM_RUNNING);
     }
     else
     {
-        GpeEventInfo->Flags &= ~ACPI_GPE_SYSTEM_RUNNING;
+        ACPI_CLEAR_BIT (GpeEventInfo->Flags, ACPI_GPE_SYSTEM_RUNNING);
     }
 
     /*
@@ -739,9 +741,11 @@ AcpiEvGpeDispatch (
     {
     case ACPI_GPE_DISPATCH_HANDLER:
 
-        /* Invoke the installed handler (at interrupt level) */
-
-        GpeEventInfo->Dispatch.Handler->Address ((void *)
+        /*
+         * Invoke the installed handler (at interrupt level)
+         * Ignore return status for now.  TBD: leave GPE disabled on error?
+         */
+        (void) GpeEventInfo->Dispatch.Handler->Address (
                         GpeEventInfo->Dispatch.Handler->Context);
 
         /* It is now safe to clear level-triggered events. */
diff --git a/sys/contrib/dev/acpica/evgpeblk.c b/sys/contrib/dev/acpica/evgpeblk.c
index b34cbe9..cc8d380 100644
--- a/sys/contrib/dev/acpica/evgpeblk.c
+++ b/sys/contrib/dev/acpica/evgpeblk.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Module Name: evgpeblk - GPE block creation and initialization.
- *              $Revision: 34 $
+ *              $Revision: 36 $
  *
  *****************************************************************************/
 
@@ -1102,8 +1102,8 @@ AcpiEvCreateGpeBlock (
     /* Dump info about this GPE block */
 
     ACPI_DEBUG_PRINT ((ACPI_DB_INIT,
-        "GPE %02d to %02d [%4.4s] %d regs at %8.8X%8.8X on int %d\n",
-        GpeBlock->BlockBaseNumber,
+        "GPE %02X to %02X [%4.4s] %u regs at %8.8X%8.8X on int 0x%X\n",
+        (UINT32) GpeBlock->BlockBaseNumber,
         (UINT32) (GpeBlock->BlockBaseNumber +
                 ((GpeBlock->RegisterCount * ACPI_GPE_REGISTER_WIDTH) -1)),
         GpeDevice->Name.Ascii,
diff --git a/sys/contrib/dev/acpica/exconfig.c b/sys/contrib/dev/acpica/exconfig.c
index e3ed108..4686b4a 100644
--- a/sys/contrib/dev/acpica/exconfig.c
+++ b/sys/contrib/dev/acpica/exconfig.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Module Name: exconfig - Namespace reconfiguration (Load/Unload opcodes)
- *              $Revision: 77 $
+ *              $Revision: 78 $
  *
  *****************************************************************************/
 
@@ -415,7 +415,7 @@ AcpiExLoadOp (
         for (i = 0; i < 8; i++)
         {
             Status = AcpiEvAddressSpaceDispatch (ObjDesc, ACPI_READ,
-                                (ACPI_PHYSICAL_ADDRESS) i + Address, 8,
+                                (ACPI_PHYSICAL_ADDRESS) (i + Address), 8,
                                 ((UINT8 *) &TableHeader) + i);
             if (ACPI_FAILURE (Status))
             {
@@ -443,7 +443,7 @@ AcpiExLoadOp (
         for (i = 0; i < TableHeader.Length; i++)
         {
             Status = AcpiEvAddressSpaceDispatch (ObjDesc, ACPI_READ,
-                                (ACPI_PHYSICAL_ADDRESS) i + Address, 8,
+                                (ACPI_PHYSICAL_ADDRESS) (i + Address), 8,
                                 ((UINT8 *) TablePtr + i));
             if (ACPI_FAILURE (Status))
             {
diff --git a/sys/contrib/dev/acpica/tbxfroot.c b/sys/contrib/dev/acpica/tbxfroot.c
index 01b9dd3..4356602 100644
--- a/sys/contrib/dev/acpica/tbxfroot.c
+++ b/sys/contrib/dev/acpica/tbxfroot.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Module Name: tbxfroot - Find the root ACPI table (RSDT)
- *              $Revision: 72 $
+ *              $Revision: 73 $
  *
  *****************************************************************************/
 
@@ -486,14 +486,17 @@ AcpiTbScanMemoryForRsdp (
  *              Flags                   - Current memory mode (logical vs.
  *                                        physical addressing)
  *
- * RETURN:      Status
+ * RETURN:      Status, RSDP physical address
  *
  * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor
  *              pointer structure.  If it is found, set *RSDP to point to it.
  *
- *              NOTE: The RSDP must be either in the first 1K of the Extended
- *              BIOS Data Area or between E0000 and FFFFF (ACPI 1.0 section
- *              5.2.2; assertion #421).
+ *              NOTE1: The RSDP must be either in the first 1K of the Extended
+ *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
+ *              Only a 32-bit physical address is necessary.
+ *
+ *              NOTE2: This function is always available, regardless of the
+ *              initialization state of the rest of ACPI.
  *
  ******************************************************************************/
 
@@ -504,8 +507,8 @@ AcpiTbFindRsdp (
 {
     UINT8                   *TablePtr;
     UINT8                   *MemRover;
-    UINT64                  PhysAddr;
-    ACPI_STATUS             Status = AE_OK;
+    UINT32                  PhysicalAddress;
+    ACPI_STATUS             Status;
 
 
     ACPI_FUNCTION_TRACE ("TbFindRsdp");
@@ -517,39 +520,62 @@ AcpiTbFindRsdp (
     if ((Flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING)
     {
         /*
-         * 1) Search EBDA (low memory) paragraphs
+         * 1a) Get the location of the EBDA
          */
-        Status = AcpiOsMapMemory ((UINT64) ACPI_LO_RSDP_WINDOW_BASE, ACPI_LO_RSDP_WINDOW_SIZE,
+        Status = AcpiOsMapMemory ((ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION,
+                                    ACPI_EBDA_PTR_LENGTH,
                                     (void *) &TablePtr);
         if (ACPI_FAILURE (Status))
         {
-            ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %X for length %X\n",
-                ACPI_LO_RSDP_WINDOW_BASE, ACPI_LO_RSDP_WINDOW_SIZE));
+            ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X for length %X\n",
+                ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
             return_ACPI_STATUS (Status);
         }
 
-        MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_LO_RSDP_WINDOW_SIZE);
-        AcpiOsUnmapMemory (TablePtr, ACPI_LO_RSDP_WINDOW_SIZE);
+        ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr);
+        PhysicalAddress <<= 4;                  /* Convert segment to physical address */
+        AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH);
 
-        if (MemRover)
+        /* EBDA present? */
+
+        if (PhysicalAddress > 0x400)
         {
-            /* Found it, return the physical address */
+            /*
+             * 1b) Search EBDA paragraphs (EBDA is required to be a minimum of 1K length)
+             */
+            Status = AcpiOsMapMemory ((ACPI_PHYSICAL_ADDRESS) PhysicalAddress,
+                                        ACPI_EBDA_WINDOW_SIZE,
+                                        (void *) &TablePtr);
+            if (ACPI_FAILURE (Status))
+            {
+                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X for length %X\n",
+                    PhysicalAddress, ACPI_EBDA_WINDOW_SIZE));
+                return_ACPI_STATUS (Status);
+            }
 
-            PhysAddr = ACPI_LO_RSDP_WINDOW_BASE;
-            PhysAddr += ACPI_PTR_DIFF (MemRover,TablePtr);
+            MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_EBDA_WINDOW_SIZE);
+            AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE);
 
-            TableInfo->PhysicalAddress = PhysAddr;
-            return_ACPI_STATUS (AE_OK);
+            if (MemRover)
+            {
+                /* Found it, return the physical address */
+
+                PhysicalAddress += ACPI_PTR_DIFF (MemRover, TablePtr);
+
+                TableInfo->PhysicalAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress;
+                return_ACPI_STATUS (AE_OK);
+            }
         }
 
         /*
-         * 2) Search upper memory: 16-byte boundaries in E0000h-F0000h
+         * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
          */
-        Status = AcpiOsMapMemory ((UINT64) ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE,
+        Status = AcpiOsMapMemory ((ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE,
+                                    ACPI_HI_RSDP_WINDOW_SIZE,
                                     (void *) &TablePtr);
         if (ACPI_FAILURE (Status))
         {
-            ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %X for length %X\n",
+            ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X for length %X\n",
                 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE));
             return_ACPI_STATUS (Status);
         }
@@ -561,10 +587,9 @@ AcpiTbFindRsdp (
         {
             /* Found it, return the physical address */
 
-            PhysAddr = ACPI_HI_RSDP_WINDOW_BASE;
-            PhysAddr += ACPI_PTR_DIFF (MemRover, TablePtr);
+            PhysicalAddress = ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr);
 
-            TableInfo->PhysicalAddress = PhysAddr;
+            TableInfo->PhysicalAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress;
             return_ACPI_STATUS (AE_OK);
         }
     }
@@ -575,20 +600,31 @@ AcpiTbFindRsdp (
     else
     {
         /*
-         * 1) Search EBDA (low memory) paragraphs
+         * 1a) Get the location of the EBDA
          */
-        MemRover = AcpiTbScanMemoryForRsdp (ACPI_PHYSADDR_TO_PTR (ACPI_LO_RSDP_WINDOW_BASE),
-                        ACPI_LO_RSDP_WINDOW_SIZE);
-        if (MemRover)
+        ACPI_MOVE_16_TO_32 (&PhysicalAddress, ACPI_EBDA_PTR_LOCATION);
+        PhysicalAddress <<= 4;      /* Convert segment to physical address */
+
+        /* EBDA present? */
+
+        if (PhysicalAddress > 0x400)
         {
-            /* Found it, return the physical address */
+            /*
+             * 1b) Search EBDA paragraphs (EBDA is required to be a minimum of 1K length)
+             */
+            MemRover = AcpiTbScanMemoryForRsdp (ACPI_PHYSADDR_TO_PTR (PhysicalAddress),
+                            ACPI_EBDA_WINDOW_SIZE);
+            if (MemRover)
+            {
+                /* Found it, return the physical address */
 
-            TableInfo->PhysicalAddress = ACPI_TO_INTEGER (MemRover);
-            return_ACPI_STATUS (AE_OK);
+                TableInfo->PhysicalAddress = ACPI_TO_INTEGER (MemRover);
+                return_ACPI_STATUS (AE_OK);
+            }
         }
 
         /*
-         * 2) Search upper memory: 16-byte boundaries in E0000h-F0000h
+         * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
          */
         MemRover = AcpiTbScanMemoryForRsdp (ACPI_PHYSADDR_TO_PTR (ACPI_HI_RSDP_WINDOW_BASE),
                         ACPI_HI_RSDP_WINDOW_SIZE);