Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include "expand.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,
};

#define cga     ((uchar*)0xB8000)
int cgapos;

static uchar
cgaregr(int index)
{
        outb(0x3D4, index);
        return inb(0x3D4+1) & 0xFF;
}

static void
cgaregw(int index, int data)
{
        outb(0x3D4, index);
        outb(0x3D4+1, data);
}

static void
movecursor(void)
{
        cgaregw(0x0E, (cgapos/2>>8) & 0xFF);
        cgaregw(0x0F, cgapos/2 & 0xFF);
        cga[cgapos+1] = Attr;
}

void
cgaputc(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)
                        cgaputc(' ');
        }
        else if(c == '\b'){
                if(cgapos >= 2)
                        cgapos -= 2;
                cgaputc(' ');
                cgapos -= 2;
        }
        else{
                cga[cgapos++] = c;
                cga[cgapos++] = Attr;
        }
        if(cgapos >= Width*Height){
                memmove(cga, &cga[Width], Width*(Height-1));
                p = &cga[Width*(Height-1)];
                for(i=0; i<Width/2; i++){
                        *p++ = ' ';
                        *p++ = Attr;
                }
                cgapos = Width*(Height-1);
        }
        movecursor();
}

void
cgainit(void)
{
        cgapos = cgaregr(0x0E)<<8;
        cgapos |= cgaregr(0x0F);
        cgapos *= 2;
}