nuclear@0: #include <stdio.h>
nuclear@0: #include <string.h>
nuclear@0: #include "vbe.h"
nuclear@0: #include "dpmi.h"
nuclear@0: 
nuclear@0: /* VGA DAC registers used for palette setting in 8bpp modes */
nuclear@0: #define VGA_DAC_STATE		0x3c7
nuclear@0: #define VGA_DAC_ADDR_RD		0x3c7
nuclear@0: #define VGA_DAC_ADDR_WR		0x3c8
nuclear@0: #define VGA_DAC_DATA		0x3c9
nuclear@0: 
nuclear@0: #define MODE_LFB	(1 << 14)
nuclear@0: 
nuclear@0: 
nuclear@0: struct vbe_info *vbe_get_info(void)
nuclear@0: {
nuclear@0: 	static unsigned short info_block_seg;
nuclear@0: 	static struct vbe_info *info;
nuclear@0: 	struct dpmi_real_regs regs;
nuclear@0: 
nuclear@0: 	if(!info) {
nuclear@0: 		/* allocate 32 paragraphs (512 bytes) */
nuclear@0: 		info_block_seg = dpmi_alloc(32);
nuclear@0: 		info = (struct vbe_info*)(info_block_seg << 4);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	memcpy(info->sig, "VBE2", 4);
nuclear@0: 
nuclear@0: 	memset(&regs, 0, sizeof regs);
nuclear@0: 	regs.es = info_block_seg;
nuclear@0: 	regs.eax = 0x4f00;
nuclear@0: 
nuclear@0: 	dpmi_real_int(0x10, &regs);
nuclear@0: 
nuclear@0: 	return info;
nuclear@0: }
nuclear@0: 
nuclear@0: struct vbe_mode_info *vbe_get_mode_info(int mode)
nuclear@0: {
nuclear@0: 	static unsigned short mode_info_seg;
nuclear@0: 	static struct vbe_mode_info *mi;
nuclear@0: 	struct dpmi_real_regs regs;
nuclear@0: 
nuclear@0: 	if(!mi) {
nuclear@0: 		/* allocate 16 paragraphs (256 bytes) */
nuclear@0: 		mode_info_seg = dpmi_alloc(16);
nuclear@0: 		mi = (struct vbe_mode_info*)(mode_info_seg << 4);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	memset(&regs, 0, sizeof regs);
nuclear@0: 	regs.es = mode_info_seg;
nuclear@0: 	regs.eax = 0x4f01;
nuclear@0: 	regs.ecx = mode;
nuclear@0: 	regs.es = mode_info_seg;
nuclear@0: 
nuclear@0: 	dpmi_real_int(0x10, &regs);
nuclear@0: 	if(regs.eax & 0xff00) {
nuclear@0: 		return 0;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return mi;
nuclear@0: }
nuclear@0: 
nuclear@0: int vbe_set_mode(int mode)
nuclear@0: {
nuclear@0: 	struct dpmi_real_regs regs;
nuclear@0: 
nuclear@0: 	memset(&regs, 0, sizeof regs);
nuclear@0: 	regs.eax = 0x4f02;
nuclear@0: 	regs.ebx = mode;
nuclear@0: 	dpmi_real_int(0x10, &regs);
nuclear@0: 
nuclear@0: 	if(regs.eax == 0x100) {
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: int vbe_set_palette_bits(int bits)
nuclear@0: {
nuclear@0: 	struct dpmi_real_regs regs;
nuclear@0: 
nuclear@0: 	memset(&regs, 0, sizeof regs);
nuclear@0: 	regs.eax = 0x4f08;
nuclear@0: 	regs.ebx = bits << 8;	/* bits in bh */
nuclear@0: 	dpmi_real_int(0x10, &regs);
nuclear@0: 
nuclear@0: 	if((regs.eax >> 8) & 0xff == 3) {
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	return regs.ebx >> 8 & 0xff;	/* new color bits in bh */
nuclear@0: }
nuclear@0: 
nuclear@0: /* TODO: implement palette setting through the VBE2 interface for
nuclear@0:  * non-VGA displays (actually don't).
nuclear@0:  */
nuclear@0: void vbe_set_palette(int idx, int *col, int count, int bits)
nuclear@0: {
nuclear@0: 	int i, shift = 8 - bits;
nuclear@0: 
nuclear@0: 	__asm {
nuclear@0: 		mov dx, VGA_DAC_ADDR_WR
nuclear@0: 		mov eax, idx
nuclear@0: 		out dx, al
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	for(i=0; i<count; i++) {
nuclear@0: 		unsigned char r = *col++;
nuclear@0: 		unsigned char g = *col++;
nuclear@0: 		unsigned char b = *col++;
nuclear@0: 
nuclear@0: 		if(shift) {
nuclear@0: 			r >>= shift;
nuclear@0: 			g >>= shift;
nuclear@0: 			b >>= shift;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		__asm {
nuclear@0: 			mov dx, VGA_DAC_DATA
nuclear@0: 			mov al, r
nuclear@0: 			out dx, al
nuclear@0: 			mov al, g
nuclear@0: 			out dx, al
nuclear@0: 			mov al, b
nuclear@0: 			out dx, al
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: static unsigned int get_mask(int sz, int pos)
nuclear@0: {
nuclear@0: 	unsigned int i, mask = 0;
nuclear@0: 
nuclear@0: 	for(i=0; i<sz; i++) {
nuclear@0: 		mask |= 1 << i;
nuclear@0: 	}
nuclear@0: 	return mask << pos;
nuclear@0: }
nuclear@0: 
nuclear@0: void print_mode_info(FILE *fp, struct vbe_mode_info *mi)
nuclear@0: {
nuclear@0: 	fprintf(fp, "resolution: %dx%d\n", mi->xres, mi->yres);
nuclear@0: 	fprintf(fp, "color depth: %d\n", mi->bpp);
nuclear@0: 	fprintf(fp, "mode attributes: %x\n", mi->mode_attr);
nuclear@0: 	fprintf(fp, "bytes per scanline: %d\n", mi->scanline_bytes);
nuclear@0: 	fprintf(fp, "number of planes: %d\n", (int)mi->num_planes);
nuclear@0: 	fprintf(fp, "number of banks: %d\n", (int)mi->num_banks);
nuclear@0: 	fprintf(fp, "mem model: %d\n", (int)mi->mem_model);
nuclear@0: 	fprintf(fp, "red bits: %d (mask: %x)\n", (int)mi->rmask_size, get_mask(mi->rmask_size, mi->rpos));
nuclear@0: 	fprintf(fp, "green bits: %d (mask: %x)\n", (int)mi->gmask_size, get_mask(mi->gmask_size, mi->gpos));
nuclear@0: 	fprintf(fp, "blue bits: %d (mask: %x)\n", (int)mi->bmask_size, get_mask(mi->bmask_size, mi->bpos));
nuclear@0: 	fprintf(fp, "framebuffer address: %x\n", mi->fb_addr);
nuclear@0: }