startup.s

最新的grub2源代码

	
	call	prot_to_real	/* enter real mode */
	.code16

	movb	$0x1, %ah
	int	$0x16

	jz	notpending
	
	movw	%ax, %dx
	DATA32	jmp	pending

notpending:
	decl	%edx

pending:
	DATA32	call	real_to_prot
	.code32

	movl	%edx, %eax

	popl	%ebp
	ret

	
/*
 * grub_uint16_t grub_console_getxy (void)
 * BIOS call "INT 10H Function 03h" to get cursor position
 *	Call with	%ah = 0x03
 *			%bh = page
 *      Returns         %ch = starting scan line
 *                      %cl = ending scan line
 *                      %dh = row (0 is top)
 *                      %dl = column (0 is left)
 */


FUNCTION(grub_console_getxy)
	pushl	%ebp
	pushl	%ebx                    /* save EBX */

	call	prot_to_real
	.code16

        xorb	%bh, %bh                /* set page to 0 */
	movb	$0x3, %ah
	int	$0x10			/* get cursor position */

	DATA32	call	real_to_prot
	.code32

	movb	%dl, %ah
	movb	%dh, %al

	popl	%ebx
	popl	%ebp
	ret


/*
 * void grub_console_gotoxy(grub_uint8_t x, grub_uint8_t y)
 * BIOS call "INT 10H Function 02h" to set cursor position
 *	Call with	%ah = 0x02
 *			%bh = page
 *                      %dh = row (0 is top)
 *                      %dl = column (0 is left)
 */


FUNCTION(grub_console_gotoxy)
	pushl	%ebp
	pushl	%ebx                    /* save EBX */

	movb	%dl, %dh	/* %dh = y */
	movb	%al, %dl	/* %dl = x */

	call	prot_to_real
	.code16

        xorb	%bh, %bh                /* set page to 0 */
	movb	$0x2, %ah
	int	$0x10			/* set cursor position */

	DATA32	call	real_to_prot
	.code32

	popl	%ebx
	popl	%ebp
	ret

	
/*
 * void grub_console_cls (void)
 * BIOS call "INT 10H Function 09h" to write character and attribute
 *	Call with	%ah = 0x09
 *                      %al = (character)
 *                      %bh = (page number)
 *                      %bl = (attribute)
 *                      %cx = (number of times)
 */

FUNCTION(grub_console_cls)
	pushl	%ebp
	pushl	%ebx                    /* save EBX */

	call	prot_to_real
	.code16

	/* move the cursor to the beginning */
	movb	$0x02, %ah
	xorb	%bh, %bh
	xorw	%dx, %dx
	int	$0x10

	/* write spaces to the entire screen */
	movw	$0x0920, %ax
	movw	$0x07, %bx
	movw	$(80 * 25), %cx
        int	$0x10

	/* move back the cursor */
	movb	$0x02, %ah
	int	$0x10

	DATA32	call	real_to_prot
	.code32

	popl	%ebx
	popl	%ebp
	ret

	
/*
 * void grub_console_setcursor (int on)
 * BIOS call "INT 10H Function 01h" to set cursor type
 *      Call with       %ah = 0x01
 *                      %ch = cursor starting scanline
 *                      %cl = cursor ending scanline
 */

console_cursor_state:
	.byte	1
console_cursor_shape:
	.word	0
	
FUNCTION(grub_console_setcursor)
	pushl	%ebp
	pushl	%ebx

	/* push ON */
	pushl	%eax
	
	/* check if the standard cursor shape has already been saved */
	movw	console_cursor_shape, %ax
	testw	%ax, %ax
	jne	1f

	call	prot_to_real
	.code16

	movb	$0x03, %ah
	xorb	%bh, %bh
	int	$0x10

	DATA32	call	real_to_prot
	.code32

	movw	%cx, console_cursor_shape
1:
	/* set %cx to the designated cursor shape */
	movw	$0x2000, %cx
	popl	%eax
	testl	%eax, %eax
	jz	2f
	movw	console_cursor_shape, %cx
2:	
	call	prot_to_real
	.code16

	movb    $0x1, %ah
	int     $0x10 

	DATA32	call	real_to_prot
	.code32

	popl	%ebx
	popl	%ebp
	ret
		
/*
 * grub_getrtsecs()
 *	if a seconds value can be read, read it and return it (BCD),
 *      otherwise return 0xFF
 * BIOS call "INT 1AH Function 02H" to check whether a character is pending
 *	Call with	%ah = 0x2
 *	Return:
 *		If RT Clock can give correct values
 *			%ch = hour (BCD)
 *			%cl = minutes (BCD)
 *                      %dh = seconds (BCD)
 *                      %dl = daylight savings time (00h std, 01h daylight)
 *			Carry flag = clear
 *		else
 *			Carry flag = set
 *                         (this indicates that the clock is updating, or
 *                          that it isn't running)
 */
FUNCTION(grub_getrtsecs)
	pushl	%ebp

	call	prot_to_real	/* enter real mode */
	.code16

	clc
	movb	$0x2, %ah
	int	$0x1a

	DATA32	jnc	gottime
	movb	$0xff, %dh

gottime:
	DATA32	call	real_to_prot
	.code32

	movb	%dh, %al

	popl	%ebp
	ret

	
/*
 * grub_get_rtc()
 *	return the real time in ticks, of which there are about
 *	18-20 per second
 */
FUNCTION(grub_get_rtc)
	pushl	%ebp

	call	prot_to_real	/* enter real mode */
	.code16

	/* %ax is already zero */
        int	$0x1a

	DATA32	call	real_to_prot
	.code32

	movl	%ecx, %eax
	shll	$16, %eax
	movw	%dx, %ax

	popl	%ebp
	ret


/*
 * unsigned char grub_vga_set_mode (unsigned char mode)
 */
FUNCTION(grub_vga_set_mode)
	pushl	%ebp
	pushl	%ebx
	movl	%eax, %ecx

	call	prot_to_real
	.code16
	/* get current mode */
	xorw	%bx, %bx
	movb	$0x0f, %ah
	int	$0x10
	movb	%al, %dl

	/* set the new mode */
	movb	%cl, %al
	xorb	%ah, %ah
	int	$0x10

	DATA32	call	real_to_prot
	.code32

	movb	%dl, %al
	popl	%ebx
	popl	%ebp
	ret


/*
 * unsigned char *grub_vga_get_font (void)
 */
FUNCTION(grub_vga_get_font)
	pushl	%ebp
	pushl	%ebx

	call	prot_to_real
	.code16
	movw	$0x1130, %ax
	movb	$0x06, %bh
	int	$0x10
	movw	%es, %bx
	movw	%bp, %dx
	DATA32	call	real_to_prot
	.code32

	movzwl	%bx, %ecx
	shll	$4, %ecx
	movw	%dx, %ax
	addl	%ecx, %eax

	popl	%ebx
	popl	%ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_get_controller_info (struct grub_vbe_info_block *controller_info)
 *
 * Register allocations for parameters:
 * %eax		*controller_info
 */
FUNCTION(grub_vbe_get_controller_info)
	pushl	%ebp
	pushl	%edi

	movw	%ax, %di	/* Store *controller_info to %edx:%di.  */
	xorw	%ax, %ax
	shrl	$4, %eax
	mov	%eax, %edx	/* prot_to_real destroys %eax.  */
	
	call	prot_to_real
	.code16

	pushw	%es

	movw	%dx, %es	/* *controller_info is now on %es:%di.  */
	movw	$0x4f00, %ax
	int	$0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	popw	%es

	DATA32 call	real_to_prot
	.code32

	movl	%edx, %eax
	andl	$0x0FFFF, %eax	/* Return value in %eax.  */
	
	popl	%edi
	popl	%ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_get_mode_info (grub_uint32_t mode,
 *					     struct grub_vbe_mode_info_block *mode_info)
 *
 * Register allocations for parameters:
 * %eax		mode
 * %edx		*mode_info
 */
FUNCTION(grub_vbe_get_mode_info)
	pushl   %ebp
	pushl   %edi

	movl	%eax, %ecx	/* Store mode number to %ecx.  */

	movw    %dx, %di	/* Store *mode_info to %edx:%di.  */
	xorw    %dx, %dx
	shrl    $4, %edx

	call    prot_to_real
	.code16

	pushw   %es

	movw    %dx, %es	/* *mode_info is now on %es:%di.  */
	movw    $0x4f01, %ax
	int     $0x10

	movw    %ax, %dx        /* real_to_prot destroys %eax.  */

	popw    %es

	DATA32 call     real_to_prot
	.code32

	movl    %edx, %eax
	andl    $0x0FFFF, %eax  /* Return value in %eax.  */

	popl    %edi
	popl    %ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_set_mode (grub_uint32_t mode,
 *					struct grub_vbe_crtc_info_block *crtc_info)
 *
 * Register allocations for parameters:
 * %eax		mode
 * %edx		*crtc_info
 */
FUNCTION(grub_vbe_set_mode)
	pushl	%ebp
	pushl	%ebx

	movl	%eax, %ebx	/* Store mode in %ebx.  */

	movw    %dx, %di	/* Store *crtc_info to %edx:%di.  */
	xorw    %dx, %dx
	shrl    $4, %edx

	call    prot_to_real
	.code16

	pushw   %es

	movw    %dx, %es	/* *crtc_info is now on %es:%di.  */

	movw	$0x4f02, %ax
	int	$0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	popw	%es

	DATA32 call	real_to_prot
	.code32
	
	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl	%ebx
	popl	%ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_get_mode (grub_uint32_t *mode)
 *
 * Register allocations for parameters:
 * %eax		*mode
 */
FUNCTION(grub_vbe_get_mode)
	pushl   %ebp
	pushl   %ebx
	pushl	%eax		/* Push *mode to stack.  */

	call    prot_to_real
	.code16

	movw    $0x4f03, %ax
	int     $0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	DATA32 call     real_to_prot
	.code32

	popl	%edi		/* Pops *mode from stack to %edi.  */
	andl	$0xFFFF, %ebx
	movl	%ebx, (%edi)

	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl    %ebx
	popl    %ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_set_memory_window (grub_uint32_t window,
 *						 grub_uint32_t position);
 *
 * Register allocations for parameters:
 * %eax		window
 * %edx		position
 */
FUNCTION(grub_vbe_set_memory_window)
	pushl	%ebp
	pushl	%ebx

	movl	%eax, %ebx

	call	prot_to_real
	.code16

	movw	$0x4f05, %ax
	andw	$0x00ff, %bx	/* BL = window, BH = 0, Set memory window.  */
	int	$0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	DATA32 call	real_to_prot
	.code32
	
	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl	%ebx
	popl	%ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_get_memory_window (grub_uint32_t window,
 * 						 grub_uint32_t *position);
 *
 * Register allocations for parameters:
 * %eax		window
 * %edx		*position
 */
FUNCTION(grub_vbe_get_memory_window)
	pushl   %ebp
	pushl   %ebx
	pushl	%edx		/* Push *position to stack.  */

	movl	%eax, %ebx	/* Store window in %ebx.  */

	call    prot_to_real
	.code16

	movw    $0x4f05, %ax
	andw	$0x00ff, %bx	/* BL = window.  */
	orw	$0x0100, %bx	/* BH = 1, Get memory window.  */
	int     $0x10

	movw	%ax, %bx	/* real_to_prot destroys %eax.  */

	DATA32 call     real_to_prot
	.code32

	popl	%edi		/* pops *position from stack to %edi.  */
	andl	$0xFFFF, %edx
	movl	%edx, (%edi)	/* Return position to caller.  */

	movw	%bx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl    %ebx
	popl    %ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_set_scanline_length (grub_uint32_t length)
 *
 * Register allocations for parameters:
 * %eax		length
 */
FUNCTION(grub_vbe_set_scanline_length)
	pushl	%ebp
	pushl	%ebx

	movl	%eax, %ecx	/* Store length in %ecx.  */

	call	prot_to_real
	.code16

	movw	$0x4f06, %ax
	movw	$0x0002, %bx	/* BL = 2, Set Scan Line in Bytes.  */
	int	$0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	DATA32 call	real_to_prot
	.code32
	
	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl	%ebx
	popl	%ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_get_scanline_length (grub_uint32_t *length)
 *
 * Register allocations for parameters:
 * %eax		*length
 */
FUNCTION(grub_vbe_get_scanline_length)
	pushl   %ebp
	pushl   %ebx
	pushl	%edx		/* Push *length to stack.  */

	call    prot_to_real
	.code16

	movw    $0x4f06, %ax
	movw	$0x0001, %bx	/* BL = 1, Get Scan Line Length (in bytes).  */
	int     $0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	DATA32 call     real_to_prot
	.code32

	popl	%edi		/* Pops *length from stack to %edi.  */
	andl	$0xFFFF, %ebx
	movl	%ebx, (%edi)	/* Return length to caller.  */

	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl    %ebx
	popl    %ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_set_display_start (grub_uint32_t x,
 *						 grub_uint32_t y)
 *
 * Register allocations for parameters:
 * %eax		x
 * %edx		y
 */
FUNCTION(grub_vbe_set_display_start)
	pushl	%ebp
	pushl	%ebx

	movl	%eax, %ecx	/* Store x in %ecx.  */

	call	prot_to_real
	.code16

	movw	$0x4f07, %ax
	movw	$0x0080, %bx	/* BL = 80h, Set Display Start 
				   during Vertical Retrace.  */
	int	$0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	DATA32 call	real_to_prot
	.code32
	
	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl	%ebx
	popl	%ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_get_display_start (grub_uint32_t *x,
 *						 grub_uint32_t *y)
 *
 * Register allocations for parameters:
 * %eax		*x
 * %edx		*y
 */
FUNCTION(grub_vbe_get_display_start)
	pushl   %ebp
	pushl   %ebx
	pushl	%eax		/* Push *x to stack.  */
	pushl	%edx		/* Push *y to stack.  */

	call    prot_to_real
	.code16

	movw    $0x4f07, %ax
	movw	$0x0001, %bx	/* BL = 1, Get Display Start.  */
	int     $0x10

	movw	%ax, %bx	/* real_to_prot destroys %eax.  */

	DATA32 call     real_to_prot
	.code32

	popl	%edi		/* Pops *y from stack to %edi.  */
	andl	$0xFFFF, %edx
	movl	%edx, (%edi)	/* Return y-position to caller.  */

	popl	%edi		/* Pops *x from stack to %edi.  */
	andl	$0xFFFF, %ecx
	movl	%ecx, (%edi)	/* Return x-position to caller.  */

	movw	%bx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl    %ebx
	popl    %ebp
	ret

/*
 * grub_vbe_status_t grub_vbe_set_palette_data (grub_uint32_t color_count,
 *						grub_uint32_t start_index,
 *						struct grub_vbe_palette_data *palette_data)
 *
 * Register allocations for parameters:
 * %eax		color_count
 * %edx		start_index
 * %ecx		*palette_data
 */
FUNCTION(grub_vbe_set_palette_data)
	pushl	%ebp
	pushl	%ebx

	movl	%eax, %ebx	/* Store color_count in %ebx.  */

	movw    %cx, %di	/* Store *palette_data to %ecx:%di.  */
	xorw    %cx, %cx
	shrl    $4, %ecx

	call    prot_to_real
	.code16

	pushw   %es

	movw    %cx, %es	/* *palette_data is now on %es:%di.  */
	movw	%bx, %cx	/* color_count is now on %cx.  */

	movw	$0x4f09, %ax
	xorw	%bx, %bx	/* BL = 0, Set Palette Data.  */
	int	$0x10

	movw	%ax, %dx	/* real_to_prot destroys %eax.  */

	popw	%es

	DATA32 call	real_to_prot
	.code32
	
	movw	%dx, %ax
	andl	$0xFFFF, %eax	/* Return value in %eax.  */

	popl	%ebx
	popl	%ebp
	ret