bootconsoleio.cpp

功能强大的开源加密软件。使用最新ieee-p1619标准

/*
 Copyright (c) 2008 TrueCrypt Foundation. All rights reserved.

 Governed by the TrueCrypt License 2.4 the full text of which is contained
 in the file License.txt included in TrueCrypt binary and source code
 distribution packages.
*/

#include "Platform.h"
#include "Bios.h"
#include "BootConsoleIo.h"
#include "BootDebug.h"


static int ScreenOutputDisabled = 0;

void DisableScreenOutput ()
{
	++ScreenOutputDisabled;
}


void EnableScreenOutput ()
{
	--ScreenOutputDisabled;
}


void PrintChar (char c)
{
#ifdef TC_BOOT_TRACING_ENABLED
	WriteDebugPort (c);
#endif

	if (ScreenOutputDisabled)
		return;

	__asm
	{
		xor bx, bx
		mov al, c
		mov ah, 0xe
		int 0x10
	}
}


void PrintCharAtCusor (char c)
{
	__asm
	{
		xor bx, bx
		mov al, c
		mov cx, 1
		mov ah, 0xa
		int 0x10
	}
}


void Print (const char *str)
{
	char c;
	while (c = *str++)
		PrintChar (c);
}


void Print (uint32 number)
{
	char str[12];
	int pos = 0;
	while (number >= 10)
	{
		str[pos++] = (number % 10) + '0';
		number /= 10;
	}
	str[pos] = (number % 10) + '0';
	
	while (pos >= 0)
		PrintChar (str[pos--]);
}


void Print (const uint64 &number)
{
	if (number.HighPart == 0)
		Print (number.LowPart);
	else
		PrintHex (number);
}


void PrintHex (byte b)
{
	PrintChar (((b >> 4) >= 0xA ? 'A' - 0xA : '0') + (b >> 4));
	PrintChar (((b & 0xF) >= 0xA ? 'A' - 0xA : '0') + (b & 0xF));
}


void PrintHex (uint16 data)
{
	PrintHex (byte (data >> 8));
	PrintHex (byte (data));
}


void PrintHex (uint32 data)
{
	PrintHex (uint16 (data >> 16));
	PrintHex (uint16 (data));
}


void PrintHex (const uint64 &data)
{
	PrintHex (data.HighPart);
	PrintHex (data.LowPart);
}

void PrintRepeatedChar (char c, int n)
{
	while (n-- > 0)
		PrintChar (c);
}


void PrintEndl ()
{
	Print ("\r\n");
}


void PrintEndl (int cnt)
{
	while (cnt-- > 0)
		PrintEndl ();
}


void Beep ()
{
	PrintChar (7);
}


void ClearScreen ()
{
	__asm
	{
		mov bh, 7
		xor cx, cx
		mov dx, 0x184f
		mov ax, 0x600
		int 0x10

		xor bh, bh
		xor dx, dx
		mov ah, 2
		int 0x10
	}
}


void PrintBackspace ()
{
	PrintChar (TC_BIOS_CHAR_BACKSPACE);
	PrintCharAtCusor (' ');
}


void PrintError (const char *message, bool beep, bool newLine)
{
	Print ("Error: ");
	Print (message);
	
	if (newLine)
		PrintEndl();

	if (beep)
		Beep();
}


byte GetShiftFlags ()
{
	byte flags;
	__asm
	{
		mov ah, 2
		int 0x16
		mov flags, al
	}

	return flags;
}


byte GetKeyboardChar (byte *scanCode)
{
	byte asciiCode;
	byte scan;
	__asm
	{
		mov ah, 0
		int 0x16
		mov asciiCode, al
		mov scan, ah
	}
	
	if (scanCode)
		*scanCode = scan;

	return asciiCode;
}


bool IsKeyboardCharAvailable ()
{
	bool available = false;
	__asm
	{
		mov ah, 1
		int 0x16
		jz not_avail
		mov available, true
	not_avail:
	}

	return available;
}


void ClearBiosKeystrokeBuffer ()
{
	__asm
	{
		push es
		xor ax, ax
		mov es, ax
		mov di, 0x41e
		mov cx, 32
		cld
		rep stosb
		pop es
	}
}


bool IsPrintable (char c)
{
	return c >= ' ' && c <= '~';
}


int GetString (char *buffer, size_t bufferSize)
{
	byte c;
	byte scanCode;
	size_t pos = 0;

	while (pos < bufferSize)
	{
		c = GetKeyboardChar (&scanCode);

		if (scanCode == TC_BIOS_KEY_ENTER)
			break;
		
		if (scanCode == TC_BIOS_KEY_ESC)
			return 0;

		buffer[pos++] = c;
		PrintChar (IsPrintable (c) ? c : ' ');
	}

	return pos;
}