// SPDX-License-Identifier: GPL-2.0/* * Procedures for drawing on the screen early on in the boot process. * * Benjamin Herrenschmidt <benh@kernel.crashing.org> */#include <linux/kernel.h>#include <linux/string.h>#include <linux/init.h>#include <linux/console.h>#include <linux/font.h> #include <asm/btext.h>#include <asm/oplib.h>#include <asm/io.h> #define NO_SCROLL #ifndef NO_SCROLLstatic void scrollscreen(void);#endif static void draw_byte(unsigned char c, long locX, long locY);static void draw_byte_32(const unsigned char *bits, unsigned int *base, int rb);static void draw_byte_16(const unsigned char *bits, unsigned int *base, int rb);static void draw_byte_8(const unsigned char *bits, unsigned int *base, int rb); #define __force_data __section(".data") static int g_loc_X __force_data;static int g_loc_Y __force_data;static int g_max_loc_X __force_data;static int g_max_loc_Y __force_data; static int dispDeviceRowBytes __force_data;static int dispDeviceDepth  __force_data;static int dispDeviceRect[4] __force_data;static unsigned char *dispDeviceBase __force_data; static int __init btext_initialize(phandle node){	unsigned int width, height, depth, pitch;	unsigned long address = 0;	u32 prop; 	if (prom_getproperty(node, "width", (char *)&width, 4) < 0)		return -EINVAL;	if (prom_getproperty(node, "height", (char *)&height, 4) < 0)		return -EINVAL;	if (prom_getproperty(node, "depth", (char *)&depth, 4) < 0)		return -EINVAL;	pitch = width * ((depth + 7) / 8); 	if (prom_getproperty(node, "linebytes", (char *)&prop, 4) >= 0 &&	    prop != 0xffffffffu)		pitch = prop; 	if (pitch == 1)		pitch = 0x1000; 	if (prom_getproperty(node, "address", (char *)&prop, 4) >= 0)		address = prop; 	/* FIXME: Add support for PCI reg properties. Right now, only	 * reliable on macs	 */	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;	dispDeviceBase = (unsigned char *)address;	dispDeviceRowBytes = pitch;	dispDeviceDepth = depth == 15 ? 16 : depth;	dispDeviceRect[0] = dispDeviceRect[1] = 0;	dispDeviceRect[2] = width;	dispDeviceRect[3] = height; 	return 0;} /* Calc the base address of a given point (x,y) */static unsigned char * calc_base(int x, int y){	unsigned char *base = dispDeviceBase; 	base += (x + dispDeviceRect[0]) * (dispDeviceDepth >> 3);	base += (y + dispDeviceRect[1]) * dispDeviceRowBytes;	return base;} static void btext_clearscreen(void){	unsigned int *base	= (unsigned int *)calc_base(0, 0);	unsigned long width 	= ((dispDeviceRect[2] - dispDeviceRect[0]) *					(dispDeviceDepth >> 3)) >> 2;	int i,j; 	for (i=0; i<(dispDeviceRect[3] - dispDeviceRect[1]); i++)	{		unsigned int *ptr = base;		for(j=width; j; --j)			*(ptr++) = 0;		base += (dispDeviceRowBytes >> 2);	}} #ifndef NO_SCROLLstatic void scrollscreen(void){	unsigned int *src     	= (unsigned int *)calc_base(0,16);	unsigned int *dst     	= (unsigned int *)calc_base(0,0);	unsigned long width    	= ((dispDeviceRect[2] - dispDeviceRect[0]) *				   (dispDeviceDepth >> 3)) >> 2;	int i,j; 	for (i=0; i<(dispDeviceRect[3] - dispDeviceRect[1] - 16); i++)	{		unsigned int *src_ptr = src;		unsigned int *dst_ptr = dst;		for(j=width; j; --j)			*(dst_ptr++) = *(src_ptr++);		src += (dispDeviceRowBytes >> 2);		dst += (dispDeviceRowBytes >> 2);	}	for (i=0; i<16; i++)	{		unsigned int *dst_ptr = dst;		for(j=width; j; --j)			*(dst_ptr++) = 0;		dst += (dispDeviceRowBytes >> 2);	}}#endif /* ndef NO_SCROLL */ static void btext_drawchar(char c){	int cline = 0;#ifdef NO_SCROLL	int x;#endif	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;		g_loc_Y++;		cline = 1;	}#ifndef NO_SCROLL	while (g_loc_Y >= g_max_loc_Y) {		scrollscreen();		g_loc_Y--;	}#else	/* wrap around from bottom to top of screen so we don't	   waste time scrolling each line.  -- paulus. */	if (g_loc_Y >= g_max_loc_Y)		g_loc_Y = 0;	if (cline) {		for (x = 0; x < g_max_loc_X; ++x)			draw_byte(' ', x, g_loc_Y);	}#endif} static void btext_drawtext(const char *c, unsigned int len){	while (len--)		btext_drawchar(*c++);} static void draw_byte(unsigned char c, long locX, long locY){	unsigned char *base	= calc_base(locX << 3, locY << 4);	unsigned int font_index = c * 16;	const unsigned char *font	= font_sun_8x16.data + font_index;	int rb			= dispDeviceRowBytes; 	switch(dispDeviceDepth) {	case 24:	case 32:		draw_byte_32(font, (unsigned int *)base, rb);		break;	case 15:	case 16:		draw_byte_16(font, (unsigned int *)base, rb);		break;	case 8:		draw_byte_8(font, (unsigned int *)base, rb);		break;	}} static unsigned int expand_bits_8[16] = {	0x00000000,	0x000000ff,	0x0000ff00,	0x0000ffff,	0x00ff0000,	0x00ff00ff,	0x00ffff00,	0x00ffffff,	0xff000000,	0xff0000ff,	0xff00ff00,	0xff00ffff,	0xffff0000,	0xffff00ff,	0xffffff00,	0xffffffff}; static unsigned int expand_bits_16[4] = {	0x00000000,	0x0000ffff,	0xffff0000,	0xffffffff};  static void draw_byte_32(const unsigned char *font, unsigned int *base, int rb){	int l, bits;	int fg = 0xFFFFFFFFUL;	int bg = 0x00000000UL; 	for (l = 0; l < 16; ++l)	{		bits = *font++;		base[0] = (-(bits >> 7) & fg) ^ bg;		base[1] = (-((bits >> 6) & 1) & fg) ^ bg;		base[2] = (-((bits >> 5) & 1) & fg) ^ bg;		base[3] = (-((bits >> 4) & 1) & fg) ^ bg;		base[4] = (-((bits >> 3) & 1) & fg) ^ bg;		base[5] = (-((bits >> 2) & 1) & fg) ^ bg;		base[6] = (-((bits >> 1) & 1) & fg) ^ bg;		base[7] = (-(bits & 1) & fg) ^ bg;		base = (unsigned int *) ((char *)base + rb);	}} static void draw_byte_16(const unsigned char *font, unsigned int *base, int rb){	int l, bits;	int fg = 0xFFFFFFFFUL;	int bg = 0x00000000UL;	unsigned int *eb = (int *)expand_bits_16; 	for (l = 0; l < 16; ++l)	{		bits = *font++;		base[0] = (eb[bits >> 6] & fg) ^ bg;		base[1] = (eb[(bits >> 4) & 3] & fg) ^ bg;		base[2] = (eb[(bits >> 2) & 3] & fg) ^ bg;		base[3] = (eb[bits & 3] & fg) ^ bg;		base = (unsigned int *) ((char *)base + rb);	}} static void draw_byte_8(const unsigned char *font, unsigned int *base, int rb){	int l, bits;	int fg = 0x0F0F0F0FUL;	int bg = 0x00000000UL;	unsigned int *eb = (int *)expand_bits_8; 	for (l = 0; l < 16; ++l)	{		bits = *font++;		base[0] = (eb[bits >> 4] & fg) ^ bg;		base[1] = (eb[bits & 0xf] & fg) ^ bg;		base = (unsigned int *) ((char *)base + rb);	}} static void btext_console_write(struct console *con, const char *s,				unsigned int n){	btext_drawtext(s, n);} static struct console btext_console = {	.name	= "btext",	.write	= btext_console_write,	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,	.index	= 0,}; int __init btext_find_display(void){	phandle node;	char type[32];	int ret; 	node = prom_inst2pkg(prom_stdout);	if (prom_getproperty(node, "device_type", type, 32) < 0)		return -ENODEV;	if (strcmp(type, "display"))		return -ENODEV; 	ret = btext_initialize(node);	if (!ret) {		btext_clearscreen();		register_console(&btext_console);	}	return ret;}