8 byte far* VGA=(byte far*) 0xA0000000; /* this points to video memory. */
\r
11 vgaSetMode(byte mode)
\r
15 regs.h.ah = SET_MODE;
\r
17 int86(VIDEO_INT, ®s, ®s);
\r
21 /* -========================= Entry Points ==========================- */
\r
25 dword far*ptr=(dword far*)VGA; /* used for faster screen clearing */
\r
27 0x0d06, /* vertical total */
\r
28 0x3e07, /* overflow (bit 8 of vertical counts) */
\r
29 0x4109, /* cell height (2 to double-scan */
\r
30 0xea10, /* v sync start */
\r
31 0xac11, /* v sync end and protect cr0-cr7 */
\r
32 0xdf12, /* vertical displayed */
\r
33 0x0014, /* turn off dword mode */
\r
34 0xe715, /* v blank start */
\r
35 0x0616, /* v blank end */
\r
36 0xe317 /* turn on byte mode */
\r
38 int CRTParmCount = sizeof(CRTParms) / sizeof(CRTParms[0]);
\r
40 /* TODO save current video mode and palette */
\r
41 vgaSetMode(VGA_256_COLOR_MODE);
\r
43 /* disable chain4 mode */
\r
44 outpw(SC_INDEX, 0x0604);
\r
46 /* synchronous reset while setting Misc Output */
\r
47 outpw(SC_INDEX, 0x0100);
\r
49 /* select 25 MHz dot clock & 60 Hz scanning rate */
\r
50 outp(MISC_OUTPUT, 0xe3);
\r
52 /* undo reset (restart sequencer) */
\r
53 outpw(SC_INDEX, 0x0300);
\r
55 /* reprogram the CRT controller */
\r
56 outp(CRTC_INDEX, 0x11); /* VSync End reg contains register write prot */
\r
57 outp(CRTC_DATA, 0x7f); /* get current write protect on varios regs */
\r
59 /* send the CRTParms */
\r
60 for(i=0; i<CRTParmCount; i++) {
\r
61 outpw(CRTC_INDEX, CRTParms[i]);
\r
64 /* clear video memory */
\r
65 outpw(SC_INDEX, 0x0f02);
\r
66 for(i=0; i<0x8000; i++) {
\r
74 /* TODO restore original mode and palette */
\r
75 vgaSetMode(TEXT_MODE);
\r
80 modexShowPage(page_t page) {
\r
84 high_address = HIGH_ADDRESS | ((word)(page) & 0xff00);
\r
85 low_address = LOW_ADDRESS | ((word)(page) << 8);
\r
87 /* wait for appropriate timing */
\r
88 while ((inp(INPUT_STATUS_1) & DISPLAY_ENABLE));
\r
89 outpw(CRTC_INDEX, high_address);
\r
90 outpw(CRTC_INDEX, low_address);
\r
92 /* wait for one retrace */
\r
93 while (!(inp(INPUT_STATUS_1) & VRETRACE));
\r
98 modexPanPage(page_t *page, int dx, int dy) {
\r
99 /* TODO figure out how the $@#! you do horizontal panning */
\r
100 *page += dy * SCREEN_WIDTH;
\r
105 modexSelectPlane(byte plane) {
\r
106 outp(SC_INDEX, MAP_MASK); /* select plane */
\r
107 outp(SC_DATA, plane);
\r
112 modexClearRegion(page_t page, int x, int y, int w, int h, byte color) {
\r
118 /* TODO Make this fast. It's SLOOOOOOW */
\r
119 for(plane=0; plane < 4; plane++) {
\r
120 modexSelectPlane(PLANE(plane+x));
\r
121 for(dx = x; dx < endx; dx+=4) {
\r
122 for(dy=y; dy<endy; dy++) {
\r
123 page[PAGE_OFFSET(dx, dy)] = color;
\r