[BOOTVID] Reorganize some definitions used in the per-architecture bootvids (#8547)

In addition:
- simplify the no-op `PrepareForSetPixel()` definitions;
- const-ify immutable data arrays for the VGA PC bootvid.

drivers/base/bootvid/arm/arm.h

@@ -7,22 +7,6 @@
 
 #pragma once
 
-extern PUSHORT VgaArmBase;
-
-#define LCDTIMING0_PPL(x)       ((((x) / 16 - 1) & 0x3f) << 2)
-#define LCDTIMING1_LPP(x)       (((x) & 0x3ff) - 1)
-#define LCDCONTROL_LCDPWR       (1 << 11)
-#define LCDCONTROL_LCDEN        (1)
-#define LCDCONTROL_LCDBPP(x)    (((x) & 7) << 1)
-#define LCDCONTROL_LCDTFT       (1 << 5)
-
-#define PL110_LCDTIMING0    (PVOID)0xE0020000
-#define PL110_LCDTIMING1    (PVOID)0xE0020004
-#define PL110_LCDTIMING2    (PVOID)0xE0020008
-#define PL110_LCDUPBASE     (PVOID)0xE0020010
-#define PL110_LCDLPBASE     (PVOID)0xE0020014
-#define PL110_LCDCONTROL    (PVOID)0xE0020018
-
 #define READ_REGISTER_ULONG(r) (*(volatile ULONG * const)(r))
 #define WRITE_REGISTER_ULONG(r, v) (*(volatile ULONG *)(r) = (v))
 
@@ -34,8 +18,7 @@ InitPaletteWithTable(
     _In_reads_(Count) const ULONG* Table,
     _In_ ULONG Count);
 
-VOID
-PrepareForSetPixel(VOID);
+#define PrepareForSetPixel()
 
 VOID
 SetPixel(

drivers/base/bootvid/arm/bootvid.c

@@ -10,8 +10,24 @@
 #define NDEBUG
 #include <debug.h>
 
-PUSHORT VgaArmBase;
-PHYSICAL_ADDRESS VgaPhysical;
+/* GLOBALS ********************************************************************/
+
+#define LCDTIMING0_PPL(x)       ((((x) / 16 - 1) & 0x3f) << 2)
+#define LCDTIMING1_LPP(x)       (((x) & 0x3ff) - 1)
+#define LCDCONTROL_LCDPWR       (1 << 11)
+#define LCDCONTROL_LCDEN        (1)
+#define LCDCONTROL_LCDBPP(x)    (((x) & 7) << 1)
+#define LCDCONTROL_LCDTFT       (1 << 5)
+
+#define PL110_LCDTIMING0    (PVOID)0xE0020000
+#define PL110_LCDTIMING1    (PVOID)0xE0020004
+#define PL110_LCDTIMING2    (PVOID)0xE0020008
+#define PL110_LCDUPBASE     (PVOID)0xE0020010
+#define PL110_LCDLPBASE     (PVOID)0xE0020014
+#define PL110_LCDCONTROL    (PVOID)0xE0020018
+
+static PUSHORT VgaArmBase;
+static PHYSICAL_ADDRESS VgaPhysical;
 
 /* PRIVATE FUNCTIONS *********************************************************/
 
@@ -31,13 +47,6 @@ VidpBuildColor(
     return ((Red & 0x1F) << 11) | ((Green & 0x1F) << 6) | ((Blue & 0x1F));
 }
 
-VOID
-PrepareForSetPixel(VOID)
-{
-    /* Nothing to prepare */
-    NOTHING;
-}
-
 FORCEINLINE
 VOID
 SetPixel(

drivers/base/bootvid/i386/pc/bootdata.c

@@ -7,12 +7,13 @@
  */
 
 #include "precomp.h"
+#include "vga.h"
 
 //
 // Minimal Attribute Controller Registers initialization command stream.
 // Compatible EGA.
 //
-USHORT AT_Initialization[] =
+const USHORT AT_Initialization[] =
 {
     /* Reset ATC to index mode */
     IB,
@@ -43,7 +44,7 @@ USHORT AT_Initialization[] =
 // 640x480 256-color 60Hz mode (BIOS mode 12) set command stream for VGA.
 // Adapted from win32ss/drivers/miniport/vga_new/vgadata.c
 //
-USHORT VGA_640x480[] =
+const USHORT VGA_640x480[] =
 {
     /* Write the Sequencer Registers */
     OWM,

drivers/base/bootvid/i386/pc/bootvid.c

@@ -12,7 +12,7 @@
 
 static BOOLEAN
 VgaInterpretCmdStream(
-    _In_ PUSHORT CmdStream)
+    _In_ const USHORT* CmdStream)
 {
     USHORT Cmd;
     UCHAR Major, Minor;
@@ -23,7 +23,8 @@ VgaInterpretCmdStream(
     USHORT ShortValue;
 
     /* First make sure that we have a Command Stream */
-    if (!CmdStream) return TRUE;
+    if (!CmdStream)
+        return TRUE;
 
     /* Loop as long as we have commands */
     while (*CmdStream != EOD)
@@ -63,7 +64,7 @@ VgaInterpretCmdStream(
                     Count = *CmdStream++;
 
                     /* Write the USHORT to the port; the buffer is what's in the command stream */
-                    WRITE_PORT_BUFFER_USHORT((PUSHORT)(VgaRegisterBase + Port), CmdStream, Count);
+                    WRITE_PORT_BUFFER_USHORT((PUSHORT)(VgaRegisterBase + Port), (PUSHORT)CmdStream, Count);
 
                     /* Move past the buffer in the command stream */
                     CmdStream += Count;

drivers/base/bootvid/i386/pc/pc.h

@@ -7,11 +7,13 @@
 
 #pragma once
 
+#include "vga.h"
+
 extern ULONG_PTR VgaRegisterBase;
 extern ULONG_PTR VgaBase;
-extern USHORT AT_Initialization[];
-extern USHORT VGA_640x480[];
-extern UCHAR PixelMask[8];
+extern const USHORT AT_Initialization[];
+extern const USHORT VGA_640x480[];
+extern const UCHAR PixelMask[8];
 
 #define __inpb(Port) \
     READ_PORT_UCHAR((PUCHAR)(VgaRegisterBase + (Port)))

drivers/base/bootvid/i386/pc/vga.c

@@ -12,7 +12,7 @@
 
 /* GLOBALS *******************************************************************/
 
-static UCHAR lMaskTable[8] =
+static const UCHAR lMaskTable[8] =
 {
     (1 << 8) - (1 << 0),
     (1 << 7) - (1 << 0),
@@ -23,7 +23,7 @@ static UCHAR lMaskTable[8] =
     (1 << 2) - (1 << 0),
     (1 << 1) - (1 << 0)
 };
-static UCHAR rMaskTable[8] =
+static const UCHAR rMaskTable[8] =
 {
     (1 << 7),
     (1 << 7) + (1 << 6),
@@ -34,7 +34,7 @@ static UCHAR rMaskTable[8] =
     (1 << 7) + (1 << 6) + (1 << 5) + (1 << 4) + (1 << 3) + (1 << 2) + (1 << 1),
     (1 << 7) + (1 << 6) + (1 << 5) + (1 << 4) + (1 << 3) + (1 << 2) + (1 << 1) + (1 << 0),
 };
-UCHAR PixelMask[8] =
+const UCHAR PixelMask[8] =
 {
     (1 << 7),
     (1 << 6),
@@ -45,7 +45,7 @@ UCHAR PixelMask[8] =
     (1 << 1),
     (1 << 0),
 };
-static ULONG lookup[16] =
+static const ULONG lookup[16] =
 {
     0x0000,
     0x0100,

drivers/base/bootvid/i386/pc98/bootvid.c

@@ -8,14 +8,17 @@
 /* INCLUDES *******************************************************************/
 
 #include "precomp.h"
+#include <drivers/pc98/video.h>
 
 /* GLOBALS ********************************************************************/
 
-static ULONG_PTR PegcControl = 0;
-ULONG_PTR FrameBuffer = 0;
+#define BYTES_PER_SCANLINE (SCREEN_WIDTH / 8)
 
 #define PEGC_MAX_COLORS    256
 
+static ULONG_PTR PegcControl = 0;
+ULONG_PTR FrameBuffer = 0;
+
 /* PRIVATE FUNCTIONS **********************************************************/
 
 static BOOLEAN
@@ -318,12 +321,6 @@ PreserveRow(
         WRITE_REGISTER_ULONG(NewPosition++, READ_REGISTER_ULONG(OldPosition++));
 }
 
-VOID
-PrepareForSetPixel(VOID)
-{
-    NOTHING;
-}
-
 VOID
 DoScroll(
     _In_ ULONG Scroll)

drivers/base/bootvid/i386/pc98/pc98.h

@@ -7,13 +7,8 @@
 
 #pragma once
 
-/* INCLUDES *******************************************************************/
-
-#include <drivers/pc98/video.h>
-
 /* GLOBALS ********************************************************************/
 
-#define BYTES_PER_SCANLINE (SCREEN_WIDTH / 8)
 #define FB_OFFSET(x, y)    ((y) * SCREEN_WIDTH + (x))
 
 extern ULONG_PTR FrameBuffer;
@@ -25,8 +20,7 @@ InitPaletteWithTable(
     _In_reads_(Count) const ULONG* Table,
     _In_ ULONG Count);
 
-VOID
-PrepareForSetPixel(VOID);
+#define PrepareForSetPixel()
 
 FORCEINLINE
 VOID

drivers/base/bootvid/i386/xbox/bootvid.c

@@ -15,6 +15,9 @@
 
 /* GLOBALS ********************************************************************/
 
+#define BB_OFFSET(x, y)    ((y) * SCREEN_WIDTH + (x))
+#define FB_OFFSET(x, y)    (((PanV + (y)) * FrameBufferWidth + PanH + (x)) * BytesPerPixel)
+
 static ULONG_PTR FrameBufferStart = 0;
 static ULONG FrameBufferWidth, FrameBufferHeight, PanH, PanV;
 static UCHAR BytesPerPixel;
@@ -248,13 +251,6 @@ InitPaletteWithTable(
     ApplyPalette();
 }
 
-VOID
-PrepareForSetPixel(VOID)
-{
-    /* Nothing to prepare */
-    NOTHING;
-}
-
 VOID
 SetPixel(
     _In_ ULONG Left,

drivers/base/bootvid/i386/xbox/xbox.h

@@ -9,16 +9,12 @@
 
 #pragma once
 
-#define BB_OFFSET(x, y)    ((y) * SCREEN_WIDTH + (x))
-#define FB_OFFSET(x, y)    (((PanV + (y)) * FrameBufferWidth + PanH + (x)) * BytesPerPixel)
-
 VOID
 InitPaletteWithTable(
     _In_reads_(Count) const ULONG* Table,
     _In_ ULONG Count);
 
-VOID
-PrepareForSetPixel(VOID);
+#define PrepareForSetPixel()
 
 VOID
 SetPixel(