1994/0803/pc/vgas3.c (diff list | history)

pc/vgas3.c on 1994/0803
1994/0803		#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include <libg.h> #include "screen.h" #include "vga.h" /* * Hardware graphics cursor support for * generic S3 chipset. * Assume we're in enhanced mode. */ static Lock s3pagelock; static ulong storage; extern Bitmap gscreen; static void sets3page(int page) { uchar crt51; /* * I don't understand why these are different. */ if(gscreen.ldepth == 3){ /* * The S3 registers need to be unlocked for this. * Let's hope they are already: * vgaxo(Crtx, 0x38, 0x48); * vgaxo(Crtx, 0x39, 0xA0); * * The page is 6 bits, the lower 4 bits in Crt35<3:0>, * the upper 2 in Crt51<3:2>. */ vgaxo(Crtx, 0x35, page & 0x0F); crt51 = vgaxi(Crtx, 0x51) & 0xF3; vgaxo(Crtx, 0x51, crt51|((page & 0x30)>>2)); } else vgaxo(Crtx, 0x35, (page<<2) & 0x0C); } static void vsyncactive(void) { /* * Hardware cursor information is fetched from display memory * during the horizontal blank active time. The 80x chips may hang * if the cursor is turned on or off during this period. */ while((vgai(Status1) & 0x08) == 0) ; } static void disable(void) { uchar crt45; /* * Turn cursor off. */ crt45 = vgaxi(Crtx, 0x45) & 0xFE; vsyncactive(); vgaxo(Crtx, 0x45, crt45); } static void enable(void) { int i; disable(); /* * Cursor colours. Set both the CR0[EF] and the colour * stack in case we are using a 16-bit RAMDAC. */ vgaxo(Crtx, 0x0E, 0x00); vgaxo(Crtx, 0x0F, 0xFF); vgaxi(Crtx, 0x45); for(i = 0; i < 4; i++) vgaxo(Crtx, 0x4A, 0x00); vgaxi(Crtx, 0x45); for(i = 0; i < 4; i++) vgaxo(Crtx, 0x4B, 0xFF); /* * Find a place for the cursor data in display memory. * Must be on a 1024-byte boundary. */ storage = (gscreen.width*BY2WD*gscreen.r.max.y+1023)/1024; vgaxo(Crtx, 0x4C, (storage>>8) & 0x0F); vgaxo(Crtx, 0x4D, storage & 0xFF); storage *= 1024; /* * Enable the cursor in X11 mode. */ vgaxo(Crtx, 0x55, vgaxi(Crtx, 0x55)|0x10); vsyncactive(); vgaxo(Crtx, 0x45, 0x01); } static void load(Cursor *c) { uchar *and, *xor; int x, y; /* * Disable the cursor and lock the display * memory so we can update the cursor bitmap. * Set the display page (do we need to restore * the current contents when done?) and the * pointers to the two planes. */ disable(); lock(&s3pagelock); sets3page(storage>>16); and = ((uchar*)gscreen.base) + (storage & 0xFFFF); xor = and + 512; /* * The cursor is set in X11 mode which gives the following * truth table: * and xor colour * 0 0 underlying pixel colour * 0 1 underlying pixel colour * 1 0 background colour * 1 1 foreground colour * Put the cursor into the top-left of the 64x64 array. */ for(y = 0; y < 64; y++){ for(x = 0; x < 8; x++){ if(y < 16 && x < 2){ and[8*y + x] = c->clr[2*y + x]^c->set[2*y + x]; xor[8*y + x] = c->set[2*y + x]; } else { and[8*y + x] = 0; xor[8*y + x] = 0; } } } unlock(&s3pagelock); /* * Set the cursor offset and enable the cursor. */ vgaxo(Crtx, 0x4E, -c->offset.x); vgaxo(Crtx, 0x4F, -c->offset.y); vsyncactive(); vgaxo(Crtx, 0x45, 0x01); } static int move(Point p) { vgaxo(Crtx, 0x46, (p.x>>8) & 0x07); vgaxo(Crtx, 0x47, p.x & 0xFF); vgaxo(Crtx, 0x49, p.y & 0xFF); vgaxo(Crtx, 0x48, (p.y>>8) & 0x07); return 0; } Hwgc s3hwgc = { "s3hwgc", enable, load, move, disable, }; void s3page(int page) { if(hwgc == &s3hwgc){ lock(&s3pagelock); sets3page(page); unlock(&s3pagelock); } else sets3page(page); }