ref: db46e826c23973ee2cdc93a2fcbe465fc022d0ff
dir: /sys/src/9/kw/cga.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" enum { Black, Blue, Green, Cyan, Red, Magenta, Brown, Grey, Bright = 0x08, Blinking = 0x80, Yellow = Bright|Brown, White = Bright|Grey, }; enum { Width = 80*2, Height = 25, Attr = (Black<<4)|Grey, /* high nibble background * low foreground */ }; #define CGASCREENBASE ((uchar*)KADDR(0xB8000)) #define inb(x) 0 /* TODO */ #define outb(x, y) /* TODO */ static int cgapos; static Lock cgascreenlock; static uchar cgaregr(int index) { USED(index); outb(0x3D4, index); return inb(0x3D4+1) & 0xFF; } static void cgaregw(int index, int data) { USED(index, data); outb(0x3D4, index); outb(0x3D4+1, data); } static void movecursor(void) { cgaregw(0x0E, (cgapos/2>>8) & 0xFF); cgaregw(0x0F, cgapos/2 & 0xFF); CGASCREENBASE[cgapos+1] = Attr; } static void cgascreenputc(int c) { int i; uchar *p; if(c == '\n'){ cgapos = cgapos/Width; cgapos = (cgapos+1)*Width; } else if(c == '\t'){ i = 8 - ((cgapos/2)&7); while(i-->0) cgascreenputc(' '); } else if(c == '\b'){ if(cgapos >= 2) cgapos -= 2; cgascreenputc(' '); cgapos -= 2; } else{ CGASCREENBASE[cgapos++] = c; CGASCREENBASE[cgapos++] = Attr; } if(cgapos >= Width*Height){ memmove(CGASCREENBASE, &CGASCREENBASE[Width], Width*(Height-1)); p = &CGASCREENBASE[Width*(Height-1)]; for(i=0; i<Width/2; i++){ *p++ = ' '; *p++ = Attr; } cgapos = Width*(Height-1); } movecursor(); } static void cgascreenputs(char* s, int n) { if(!islo()){ /* * Don't deadlock trying to * print in an interrupt. */ if(!canlock(&cgascreenlock)) return; } else lock(&cgascreenlock); while(n-- > 0) cgascreenputc(*s++); unlock(&cgascreenlock); } void screeninit(void) { cgapos = cgaregr(0x0E)<<8; cgapos |= cgaregr(0x0F); cgapos *= 2; screenputs = cgascreenputs; }