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

#pragma once

extern ULONG_PTR VgaRegisterBase;
extern ULONG_PTR VgaBase;
extern USHORT AT_Initialization[];
extern USHORT VGA_640x480[];
extern UCHAR PixelMask[8];

#define __inpb(Port) \
    READ_PORT_UCHAR((PUCHAR)(VgaRegisterBase + (Port)))

#define __inpw(Port) \
    READ_PORT_USHORT((PUSHORT)(VgaRegisterBase + (Port)))

#define __outpb(Port, Value) \
    WRITE_PORT_UCHAR((PUCHAR)(VgaRegisterBase + (Port)), (UCHAR)(Value))

#define __outpw(Port, Value) \
    WRITE_PORT_USHORT((PUSHORT)(VgaRegisterBase + (Port)), (USHORT)(Value))

VOID
NTAPI
InitPaletteWithTable(
    _In_ PULONG Table,
    _In_ ULONG Count);

VOID
PrepareForSetPixel(VOID);

FORCEINLINE
VOID
SetPixel(
    _In_ ULONG Left,
    _In_ ULONG Top,
    _In_ UCHAR Color)
{
    PUCHAR PixelPosition;

    /* Calculate the pixel position */
    PixelPosition = (PUCHAR)(VgaBase + (Left >> 3) + (Top * (SCREEN_WIDTH / 8)));

    /* Select the bitmask register and write the mask */
    __outpw(VGA_BASE_IO_PORT + GRAPH_ADDRESS_PORT, (PixelMask[Left & 7] << 8) | IND_BIT_MASK);

    /* Read the current pixel value and add our color */
    WRITE_REGISTER_UCHAR(PixelPosition, READ_REGISTER_UCHAR(PixelPosition) & Color);
}

VOID
NTAPI
PreserveRow(
    _In_ ULONG CurrentTop,
    _In_ ULONG TopDelta,
    _In_ BOOLEAN Restore);

VOID
NTAPI
DoScroll(
    _In_ ULONG Scroll);

VOID
NTAPI
DisplayCharacter(
    _In_ CHAR Character,
    _In_ ULONG Left,
    _In_ ULONG Top,
    _In_ ULONG TextColor,
    _In_ ULONG BackColor);