btext.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 752 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/prom.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;

static int dispDeviceRowBytes;
static int dispDeviceDepth;
static int dispDeviceRect[4];
static unsigned char *dispDeviceBase, *logicalDisplayBase;

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;


/* 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;
	unsigned char *vbase;

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

int btext_initialize(struct device_node *np)
{
	unsigned int width, height, depth, pitch;
	unsigned long address = 0;
	u32 *prop;

	prop = (u32 *)get_property(np, "width", NULL);
	if (prop == NULL)
		return -EINVAL;
	width = *prop;
	prop = (u32 *)get_property(np, "height", NULL);
	if (prop == NULL)
		return -EINVAL;
	height = *prop;
	prop = (u32 *)get_property(np, "depth", NULL);
	if (prop == NULL)
		return -EINVAL;
	depth = *prop;
	pitch = width * ((depth + 7) / 8);
	prop = (u32 *)get_property(np, "linebytes", NULL);
	if (prop)
		pitch = *prop;
	if (pitch == 1)
		pitch = 0x1000;
	prop = (u32 *)get_property(np, "address", NULL);
	if (prop)
		address = *prop;

	/* FIXME: Add support for PCI reg properties */

	if (address == 0)
		return -EINVAL;

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

	map_boot_text();

	return 0;
}


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

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

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

	dispDeviceBase = (__u8 *) phys;
	dispDeviceRect[0] = 0;
	dispDeviceRect[1] = 0;
	dispDeviceRect[2] = width;
	dispDeviceRect[3] = height;
	dispDeviceDepth = depth;
	dispDeviceRowBytes = pitch;
	if (boot_text_mapped) {
		iounmap(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 *base	= (unsigned long *)calc_base(0, 0);
	unsigned long width 	= ((dispDeviceRect[2] - dispDeviceRect[0]) *
					(dispDeviceDepth >> 3)) >> 3;
	int i,j;

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

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

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

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

	switch (c) {
	case '\b':
		if (g_loc_X > 0)
			--g_loc_X;
		break;
	case '\t':
		g_loc_X = (g_loc_X & -8) + 8;
		break;
	case '\r':
		g_loc_X = 0;
		break;
	case '\n':
		g_loc_X = 0;
		g_loc_Y++;
		cline = 1;
		break;
	default:
		draw_byte(c, g_loc_X++, g_loc_Y);
	}
	if (g_loc_X >= g_max_loc_X) {
		g_loc_X = 0;