[NTVDM]

When the VGA memory map is A0000-BFFFF, mirror the bottom 64 KB into the top.
This should take care of all VGA addressing problems.

svn path=/trunk/; revision=67377

diff --git a/reactos/subsystems/mvdm/ntvdm/hardware/video/vga.c b/reactos/subsystems/mvdm/ntvdm/hardware/video/vga.c
index 3562d79..5e322b5 100644 (file)
--- a/reactos/subsystems/mvdm/ntvdm/hardware/video/vga.c
+++ b/reactos/subsystems/mvdm/ntvdm/hardware/video/vga.c
@@ -22,7 +22,7 @@
 /* PRIVATE VARIABLES **********************************************************/
 
 static CONST DWORD MemoryBase[]  = { 0xA0000, 0xA0000, 0xB0000, 0xB8000 };
 /* PRIVATE VARIABLES **********************************************************/
 
 static CONST DWORD MemoryBase[]  = { 0xA0000, 0xA0000, 0xB0000, 0xB8000 };

-static CONST DWORD MemoryLimit[] = { 0xAFFFF, 0xAFFFF, 0xB7FFF, 0xBFFFF };
+static CONST DWORD MemoryLimit[] = { 0xBFFFF, 0xAFFFF, 0xB7FFF, 0xBFFFF };

 
 /*
  * Activate this line if you want to use the real
 
 /*
  * Activate this line if you want to use the real


@@ -622,7 +622,7 @@ static inline DWORD VgaGetAddressSize(VOID)
 
 static inline DWORD VgaTranslateReadAddress(DWORD Address)
 {
 
 static inline DWORD VgaTranslateReadAddress(DWORD Address)
 {

-    DWORD Offset = Address - VgaGetVideoBaseAddress();
+    DWORD Offset = LOWORD(Address - VgaGetVideoBaseAddress());

     BYTE Plane;
 
     /* Check for chain-4 and odd-even mode */
     BYTE Plane;
 
     /* Check for chain-4 and odd-even mode */


@@ -649,7 +649,7 @@ static inline DWORD VgaTranslateReadAddress(DWORD Address)
 
 static inline DWORD VgaTranslateWriteAddress(DWORD Address)
 {
 
 static inline DWORD VgaTranslateWriteAddress(DWORD Address)
 {

-    DWORD Offset = Address - VgaGetVideoBaseAddress();
+    DWORD Offset = LOWORD(Address - VgaGetVideoBaseAddress());

 
     /* Check for chain-4 and odd-even mode */
     if (VgaSeqRegisters[VGA_SEQ_MEM_REG] & VGA_SEQ_MEM_C4)
 
     /* Check for chain-4 and odd-even mode */
     if (VgaSeqRegisters[VGA_SEQ_MEM_REG] & VGA_SEQ_MEM_C4)


@@ -1905,8 +1905,6 @@ VOID NTAPI VgaReadMemory(ULONG Address, PVOID Buffer, ULONG Size)
     PUCHAR BufPtr = (PUCHAR)Buffer;
 
     DPRINT("VgaReadMemory: Address 0x%08X, Size %lu\n", Address, Size);
     PUCHAR BufPtr = (PUCHAR)Buffer;
 
     DPRINT("VgaReadMemory: Address 0x%08X, Size %lu\n", Address, Size);

-    Address = min(max(Address, VgaGetVideoBaseAddress()), VgaGetVideoLimitAddress());
-    Size = min(Size, VgaGetVideoLimitAddress() - Address + 1);

 
     /* Ignore if video RAM access is disabled */
     if ((VgaMiscRegister & VGA_MISC_RAM_ENABLED) == 0) return;
 
     /* Ignore if video RAM access is disabled */
     if ((VgaMiscRegister & VGA_MISC_RAM_ENABLED) == 0) return;


@@ -1934,8 +1932,6 @@ BOOLEAN NTAPI VgaWriteMemory(ULONG Address, PVOID Buffer, ULONG Size)
     PUCHAR BufPtr = (PUCHAR)Buffer;
 
     DPRINT("VgaWriteMemory: Address 0x%08X, Size %lu\n", Address, Size);
     PUCHAR BufPtr = (PUCHAR)Buffer;
 
     DPRINT("VgaWriteMemory: Address 0x%08X, Size %lu\n", Address, Size);

-    Address = min(max(Address, VgaGetVideoBaseAddress()), VgaGetVideoLimitAddress());
-    Size = min(Size, VgaGetVideoLimitAddress() - Address + 1);

 
     /* Ignore if video RAM access is disabled */
     if ((VgaMiscRegister & VGA_MISC_RAM_ENABLED) == 0) return TRUE;
 
     /* Ignore if video RAM access is disabled */
     if ((VgaMiscRegister & VGA_MISC_RAM_ENABLED) == 0) return TRUE;