btext.c

来自「优龙2410linux2.6.8内核源代码」· C语言 代码 · 共 747 行 · 第 1/3 页

/*
 * Procedures for drawing on the screen early on in the boot process.
 *
 * Benjamin Herrenschmidt <[e-mail]>
 */
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/version.h>

#include <asm/sections.h>
#include <asm/bootx.h>
#include <asm/btext.h>
#include <asm/prom.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/lmb.h>
#include <asm/processor.h>

#undef NO_SCROLL

#ifndef NO_SCROLL
static void scrollscreen(void);
#endif

static void draw_byte(unsigned char c, long locX, long locY);
static void draw_byte_32(unsigned char *bits, unsigned int *base, int rb);
static void draw_byte_16(unsigned char *bits, unsigned int *base, int rb);
static void draw_byte_8(unsigned char *bits, unsigned int *base, int rb);

static int g_loc_X;
static int g_loc_Y;
static int g_max_loc_X;
static int g_max_loc_Y;

unsigned long disp_BAT[2] __initdata = {0, 0};

#define cmapsz	(16*256)

static unsigned char vga_font[cmapsz];

int boot_text_mapped;
int force_printk_to_btext = 0;

boot_infos_t disp_bi;

/* This function will enable the early boot text when doing OF booting. This
 * way, xmon output should work too
 */
void __init btext_setup_display(int width, int height, int depth, int pitch,
		    unsigned long address)
{
	unsigned long offset = reloc_offset();
	boot_infos_t* bi = PTRRELOC(&disp_bi);

	RELOC(g_loc_X) = 0;
	RELOC(g_loc_Y) = 0;
	RELOC(g_max_loc_X) = width / 8;
	RELOC(g_max_loc_Y) = height / 16;
	bi->logicalDisplayBase = (unsigned char *)address;
	bi->dispDeviceBase = (unsigned char *)address;
	bi->dispDeviceRowBytes = pitch;
	bi->dispDeviceDepth = depth;
	bi->dispDeviceRect[0] = bi->dispDeviceRect[1] = 0;
	bi->dispDeviceRect[2] = width;
	bi->dispDeviceRect[3] = height;
	RELOC(boot_text_mapped) = 1;
}

/* Here's a small text engine to use during early boot
 * or for debugging purposes
 *
 * todo:
 *
 *  - build some kind of vgacon with it to enable early printk
 *  - move to a separate file
 *  - add a few video driver hooks to keep in sync with display
 *    changes.
 */

void map_boot_text(void)
{
	unsigned long base, offset, size;
	boot_infos_t *bi = &disp_bi;
	unsigned char *vbase;

	/* By default, we are no longer mapped */
	boot_text_mapped = 0;
	if (bi->dispDeviceBase == 0)
		return;
	base = ((unsigned long) bi->dispDeviceBase) & 0xFFFFF000UL;
	offset = ((unsigned long) bi->dispDeviceBase) - base;
	size = bi->dispDeviceRowBytes * bi->dispDeviceRect[3] + offset
		+ bi->dispDeviceRect[0];
	vbase = __ioremap(base, size, _PAGE_NO_CACHE);
	if (vbase == 0)
		return;
	bi->logicalDisplayBase = vbase + offset;
	boot_text_mapped = 1;
}

/* Calc the base address of a given point (x,y) */
static unsigned char * calc_base(boot_infos_t *bi, int x, int y)
{
	unsigned char *base;

	base = bi->logicalDisplayBase;
	if (base == 0)
		base = bi->dispDeviceBase;
	base += (x + bi->dispDeviceRect[0]) * (bi->dispDeviceDepth >> 3);
	base += (y + bi->dispDeviceRect[1]) * bi->dispDeviceRowBytes;
	return base;
}

/* Adjust the display to a new resolution */
void btext_update_display(unsigned long phys, int width, int height,
			  int depth, int pitch)
{
	boot_infos_t *bi = &disp_bi;

	if (bi->dispDeviceBase == 0)
		return;

	/* check it's the same frame buffer (within 256MB) */
	if ((phys ^ (unsigned long)bi->dispDeviceBase) & 0xf0000000)
		return;

	bi->dispDeviceBase = (__u8 *) phys;
	bi->dispDeviceRect[0] = 0;
	bi->dispDeviceRect[1] = 0;
	bi->dispDeviceRect[2] = width;
	bi->dispDeviceRect[3] = height;
	bi->dispDeviceDepth = depth;
	bi->dispDeviceRowBytes = pitch;
	if (boot_text_mapped) {
		iounmap(bi->logicalDisplayBase);
		boot_text_mapped = 0;
	}
	map_boot_text();
	g_loc_X = 0;
	g_loc_Y = 0;
	g_max_loc_X = width / 8;
	g_max_loc_Y = height / 16;
}

void btext_clearscreen(void)
{
	unsigned long offset = reloc_offset();
	boot_infos_t* bi	= PTRRELOC(&disp_bi);
	unsigned long *base	= (unsigned long *)calc_base(bi, 0, 0);
	unsigned long width 	= ((bi->dispDeviceRect[2] - bi->dispDeviceRect[0]) *
					(bi->dispDeviceDepth >> 3)) >> 3;
	int i,j;

	for (i=0; i<(bi->dispDeviceRect[3] - bi->dispDeviceRect[1]); i++)
	{
		unsigned long *ptr = base;
		for(j=width; j; --j)
			*(ptr++) = 0;
		base += (bi->dispDeviceRowBytes >> 3);
	}
}

#ifndef NO_SCROLL
static void scrollscreen(void)
{
	unsigned long offset   	= reloc_offset();
	boot_infos_t* bi       	= PTRRELOC(&disp_bi);
	unsigned long *src     	= (unsigned long *)calc_base(bi,0,16);
	unsigned long *dst     	= (unsigned long *)calc_base(bi,0,0);
	unsigned long width    	= ((bi->dispDeviceRect[2] - bi->dispDeviceRect[0]) *
				   (bi->dispDeviceDepth >> 3)) >> 3;
	int i,j;

	for (i=0; i<(bi->dispDeviceRect[3] - bi->dispDeviceRect[1] - 16); i++)
	{
		unsigned long *src_ptr = src;
		unsigned long *dst_ptr = dst;
		for(j=width; j; --j)
			*(dst_ptr++) = *(src_ptr++);
		src += (bi->dispDeviceRowBytes >> 3);
		dst += (bi->dispDeviceRowBytes >> 3);
	}
	for (i=0; i<16; i++)
	{
		unsigned long *dst_ptr = dst;
		for(j=width; j; --j)
			*(dst_ptr++) = 0;
		dst += (bi->dispDeviceRowBytes >> 3);
	}
}
#endif /* ndef NO_SCROLL */

void btext_drawchar(char c)
{
	unsigned long offset = reloc_offset();
	int cline = 0;
#ifdef NO_SCROLL
	int x;
#endif
	if (!RELOC(boot_text_mapped))
		return;

	switch (c) {
	case '\b':
		if (RELOC(g_loc_X) > 0)
			--RELOC(g_loc_X);
		break;
	case '\t':
		RELOC(g_loc_X) = (RELOC(g_loc_X) & -8) + 8;
		break;
	case '\r':
		RELOC(g_loc_X) = 0;
		break;
	case '\n':
		RELOC(g_loc_X) = 0;
		RELOC(g_loc_Y)++;
		cline = 1;
		break;
	default:
		draw_byte(c, RELOC(g_loc_X)++, RELOC(g_loc_Y));
	}
	if (RELOC(g_loc_X) >= RELOC(g_max_loc_X)) {
		RELOC(g_loc_X) = 0;
		RELOC(g_loc_Y)++;
		cline = 1;
	}
#ifndef NO_SCROLL
	while (RELOC(g_loc_Y) >= RELOC(g_max_loc_Y)) {
		scrollscreen();
		RELOC(g_loc_Y)--;
	}
#else
	/* wrap around from bottom to top of screen so we don't
	   waste time scrolling each line.  -- paulus. */
	if (RELOC(g_loc_Y) >= RELOC(g_max_loc_Y))
		RELOC(g_loc_Y) = 0;
	if (cline) {
		for (x = 0; x < RELOC(g_max_loc_X); ++x)
			draw_byte(' ', x, RELOC(g_loc_Y));
	}
#endif
}

void btext_drawstring(const char *c)
{