8 #include <sys/nearptr.h>
9 #define REALPTR(s, o) (void*)(((uint32_t)(s) << 4) - __djgpp_base_address + ((uint32_t)(o)))
11 #define REALPTR(s, o) (void*)(((uint32_t)(s) << 4) + ((uint32_t)(o)))
14 #define SAME_BPP(a, b) \
15 ((a) == (b) || ((a) == 16 && (b) == 15) || ((a) == 15 && (b) == 16) || \
16 ((a) == 32 && (b) == 24) || ((a) == 24 && (b) == 32))
18 static int vbe_init_ver;
19 static struct vbe_info vbe;
20 static int mode, pgsize, fbsize;
21 static struct vbe_mode_info mode_info;
23 static void *vpgaddr[2];
26 static int init_vbe(void)
30 if(vbe_info(&vbe) == -1) {
31 fprintf(stderr, "failed to retrieve VBE information\n");
35 vbe_print_info(stdout, &vbe);
37 num = vbe_num_modes(&vbe);
38 for(i=0; i<num; i++) {
39 struct vbe_mode_info minf;
41 if(vbe_mode_info(vbe.modes[i], &minf) == -1) {
44 printf("%04x: ", vbe.modes[i]);
45 vbe_print_mode_info(stdout, &minf);
49 vbe_init_ver = VBE_VER_MAJOR(vbe.ver);
53 void *set_video_mode(int xsz, int ysz, int bpp)
56 int best_match_mode = -1;
57 struct vbe_mode_info minf;
60 if(init_vbe() == -1) {
61 fprintf(stderr, "failed to initialize VBE\n");
64 if(vbe_init_ver < 2) {
65 fprintf(stderr, "VBE >= 2.0 required\n");
71 nmodes = vbe_num_modes(&vbe);
72 for(i=0; i<nmodes; i++) {
73 if(vbe_mode_info(vbe.modes[i], &minf) == -1) {
76 if(minf.xres != xsz || minf.yres != ysz) continue;
81 if(SAME_BPP(minf.bpp, bpp)) {
82 best_match_mode = mode;
87 if(best_match_mode == -1) {
88 fprintf(stderr, "failed to find requested video mode (%dx%d %d bpp)\n", xsz, ysz, bpp);
91 mode = best_match_mode;
94 vbe_mode_info(mode, &mode_info);
95 printf("setting video mode %x: (%dx%d %d)\n", (unsigned int)mode, mode_info.xres,
96 mode_info.yres, mode_info.bpp);
98 if(vbe_setmode(mode) == -1) {
99 fprintf(stderr, "failed to set video mode\n");
103 pgsize = mode_info.xres * mode_info.yres * (bpp / 8);
104 fbsize = mode_info.num_img_pages * pgsize;
106 vpgaddr[0] = (void*)dpmi_mmap(mode_info.fb_addr, fbsize);
108 if(mode_info.num_img_pages > 1) {
109 vpgaddr[1] = (char*)vpgaddr[0] + pgsize;
111 page_flip(FLIP_NOW); /* start with the second page visible */
120 int set_text_mode(void)
126 void *page_flip(int vsync)
129 /* page flipping not supported */
133 vbe_swap(fbidx ? pgsize : 0, vsync ? VBE_SWAP_VBLANK : VBE_SWAP_NOW);
134 fbidx = (fbidx + 1) & 1;
136 return vpgaddr[fbidx];