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发信人: GyeaonWoo (柏林恋人), 信区: Linux
标  题: Linus's Linux--kernel/console.c
发信站: 荔园晨风BBS站 (Mon Aug 25 20:39:47 2003), 站内信件

/*
 *      console.c
 *
 * This module implements the console io functions
 *      'void con_init(void)'
 *      'void con_write(struct tty_queue * queue)'
 * Hopefully this will be a rather complete VT102 implementation.
 *
 */

/*
 *  NOTE!!! We sometimes disable and enable interrupts for a short
while
 * (to put a word in video IO), but this will work even for keyboard
 * interrupts. We know interrupts aren't enabled when getting a
keyboard
 * interrupt, as we use trap-gates. Hopefully all is well.
 */

#include <linux/sched.h>
#include <linux/tty.h>
#include <asm/io.h>
#include <asm/system.h>

#define SCREEN_START 0xb8000
#define SCREEN_END   0xc0000
#define LINES 25
#define COLUMNS 80
#define NPAR 16

extern void keyboard_interrupt(void);

static unsigned long origin=SCREEN_START;
static unsigned long scr_end=SCREEN_START+LINES*COLUMNS*2;
static unsigned long pos;
static unsigned long x,y;
static unsigned long top=0,bottom=LINES;
static unsigned long lines=LINES,columns=COLUMNS;
static unsigned long state=0;
static unsigned long npar,par[NPAR];
static unsigned long ques=0;
static unsigned char attr=0x07;

/*
 * this is what the terminal answers to a ESC-Z or csi0c
 * query (= vt100 response).
 */
#define RESPONSE "\033[?1;2c"

static inline void gotoxy(unsigned int new_x,unsigned int new_y)
{
        if (new_x>=columns || new_y>=lines)
                return;
        x=new_x;
        y=new_y;
        pos=origin+((y*columns+x)<<1);
}

static inline void set_origin(void)
{
        cli();
        outb_p(12,0x3d4);
        outb_p(0xff&((origin-SCREEN_START)>>9),0x3d5);
        outb_p(13,0x3d4);
        outb_p(0xff&((origin-SCREEN_START)>>1),0x3d5);
        sti();
}

static void scrup(void)
{
        if (!top && bottom==lines) {
                origin += columns<<1;
                pos += columns<<1;
                scr_end += columns<<1;
                if (scr_end>SCREEN_END) {
                        __asm__("cld\n\t"
                                "rep\n\t"
                                "movsl\n\t"
                                "movl _columns,%1\n\t"
                                "rep\n\t"
                                "stosw"
                                ::"a" (0x0720),
                                "c" ((lines-1)*columns>>1),
                                "D" (SCREEN_START),
                                "S" (origin)
                                :"cx","di","si");
                        scr_end -= origin-SCREEN_START;
                        pos -= origin-SCREEN_START;
                        origin = SCREEN_START;
                } else {
                        __asm__("cld\n\t"
                                "rep\n\t"
                                "stosl"
                                ::"a" (0x07200720),
                                "c" (columns>>1),
                                "D" (scr_end-(columns<<1))
                                :"cx","di");
                }
                set_origin();
        } else {
                __asm__("cld\n\t"
                        "rep\n\t"
                        "movsl\n\t"
                        "movl _columns,%%ecx\n\t"
                        "rep\n\t"
                        "stosw"
                        ::"a" (0x0720),
                        "c" ((bottom-top-1)*columns>>1),
                        "D" (origin+(columns<<1)*top),
                        "S" (origin+(columns<<1)*(top+1))
                        :"cx","di","si");
        }
}

static void scrdown(void)
{
        __asm__("std\n\t"
                "rep\n\t"
                "movsl\n\t"
                "addl $2,%%edi\n\t"     /* %edi has been decremented by 4 */
                "movl _columns,%%ecx\n\t"
                "rep\n\t"
                "stosw"
                ::"a" (0x0720),
                "c" ((bottom-top-1)*columns>>1),
                "D" (origin+(columns<<1)*bottom-4),
                "S" (origin+(columns<<1)*(bottom-1)-4)
                :"ax","cx","di","si");
}

static void lf(void)
{
        if (y+1<bottom) {
                y++;
                pos += columns<<1;
                return;
        }
        scrup();
}

static void ri(void)
{
        if (y>top) {
                y--;
                pos -= columns<<1;
                return;
        }
        scrdown();
}

static void cr(void)
{
        pos -= x<<1;
        x=0;
}

static void del(void)
{
        if (x) {
                pos -= 2;
                x--;
                *(unsigned short *)pos = 0x0720;
        }
}

static void csi_J(int par)
{
        long count __asm__("cx");
        long start __asm__("di");

        switch (par) {
                case 0: /* erase from cursor to end of display */
                        count = (scr_end-pos)>>1;
                        start = pos;
                        break;
                case 1: /* erase from start to cursor */
                        count = (pos-origin)>>1;
                        start = origin;
                        break;
                case 2: /* erase whole display */
                        count = columns*lines;
                        start = origin;
                        break;
                default:
                        return;
        }
        __asm__("cld\n\t"
                "rep\n\t"
                "stosw\n\t"
                ::"c" (count),
                "D" (start),"a" (0x0720)
                :"cx","di");
}

static void csi_K(int par)
{
        long count __asm__("cx");
        long start __asm__("di");

        switch (par) {
                case 0: /* erase from cursor to end of line */
                        if (x>=columns)
                                return;
                        count = columns-x;
                        start = pos;
                        break;
                case 1: /* erase from start of line to cursor */
                        start = pos - (x<<1);
                        count = (x<columns)?x:columns;
                        break;
                case 2: /* erase whole line */
                        start = pos - (x<<1);
                        count = columns;
                        break;
                default:
                        return;
        }
        __asm__("cld\n\t"
                "rep\n\t"
                "stosw\n\t"
                ::"c" (count),
                "D" (start),"a" (0x0720)
                :"cx","di");
}

void csi_m(void)
{
        int i;

        for (i=0;i<=npar;i++)
                switch (par[i]) {
                        case 0:attr=0x07;break;
                        case 1:attr=0x0f;break;
                        case 4:attr=0x0f;break;
                        case 7:attr=0x70;break;
                        case 27:attr=0x07;break;
                }
}

static inline void set_cursor(void)
{
        cli();
        outb_p(14,0x3d4);
        outb_p(0xff&((pos-SCREEN_START)>>9),0x3d5);
        outb_p(15,0x3d4);
        outb_p(0xff&((pos-SCREEN_START)>>1),0x3d5);
        sti();
}

static void respond(struct tty_struct * tty)
{
        char * p = RESPONSE;

        cli();
        while (*p) {
                PUTCH(*p,tty->read_q);
                p++;
        }
        sti();
        copy_to_cooked(tty);
}

static void insert_char(void)
{
        int i=x;
        unsigned short tmp,old=0x0720;
        unsigned short * p = (unsigned short *) pos;

        while (i++<columns) {
                tmp=*p;
                *p=old;
                old=tmp;
                p++;
        }
}

static void insert_line(void)
{
        int oldtop,oldbottom;

        oldtop=top;
        oldbottom=bottom;
        top=y;
        bottom=lines;
        scrdown();
        top=oldtop;
        bottom=oldbottom;
}

static void delete_char(void)
{
        int i;
        unsigned short * p = (unsigned short *) pos;

        if (x>=columns)
                return;
        i = x;
        while (++i < columns) {
                *p = *(p+1);
                p++;
        }
        *p=0x0720;
}

static void delete_line(void)
{
        int oldtop,oldbottom;

        oldtop=top;
        oldbottom=bottom;
        top=y;
        bottom=lines;
        scrup();
        top=oldtop;
        bottom=oldbottom;
}

static void csi_at(int nr)
{
        if (nr>columns)
                nr=columns;
        else if (!nr)
                nr=1;
        while (nr--)
                insert_char();
}

static void csi_L(int nr)
{
        if (nr>lines)
                nr=lines;
        else if (!nr)
                nr=1;
        while (nr--)
                insert_line();
}

static void csi_P(int nr)
{
        if (nr>columns)
                nr=columns;
        else if (!nr)
                nr=1;
        while (nr--)
                delete_char();
}

static void csi_M(int nr)
{
        if (nr>lines)
                nr=lines;
        else if (!nr)
                nr=1;
        while (nr--)
                delete_line();
}

static int saved_x=0;
static int saved_y=0;

static void save_cur(void)
{
        saved_x=x;
        saved_y=y;
}

static void restore_cur(void)
{
        x=saved_x;
        y=saved_y;
        pos=origin+((y*columns+x)<<1);
}

void con_write(struct tty_struct * tty)
{
        int nr;
        char c;

        nr = CHARS(tty->write_q);
        while (nr--) {
                GETCH(tty->write_q,c);
                switch(state) {
                        case 0:
                                if (c>31 && c<127) {
                                        if (x>=columns) {
                                                x -= columns;
                                                pos -= columns<<1;
                                                lf();
                                        }
                                        __asm__("movb _attr,%%ah\n\t"
                                                "movw %%ax,%1\n\t"
                                                ::"a" (c),"m" (*(short *)pos)
                                                :"ax");
                                        pos += 2;
                                        x++;
                                } else if (c==27)
                                        state=1;
                                else if (c==10 || c==11 || c==12)
                                        lf();
                                else if (c==13)
                                        cr();
                                else if (c==ERASE_CHAR(tty))
                                        del();
                                else if (c==8) {
                                        if (x) {
                                                x--;
                                                pos -= 2;
                                        }
                                } else if (c==9) {
                                        c=8-(x&7);
                                        x += c;
                                        pos += c<<1;
                                        if (x>columns) {
                                                x -= columns;
                                                pos -= columns<<1;
                                                lf();
                                        }
                                        c=9;
                                }
                                break;
                        case 1:
                                state=0;
                                if (c=='[')
                                        state=2;
                                else if (c=='E')
                                        gotoxy(0,y+1);
                                else if (c=='M')
                                        ri();
                                else if (c=='D')
                                        lf();
                                else if (c=='Z')
                                        respond(tty);
                                else if (x=='7')
                                        save_cur();
                                else if (x=='8')
                                        restore_cur();
                                break;
                        case 2:
                                for(npar=0;npar<NPAR;npar++)
                                        par[npar]=0;
                                npar=0;
                                state=3;
                                if (ques=(c=='?'))
                                        break;
                        case 3:
                                if (c==';' && npar<NPAR-1) {
                                        npar++;
                                        break;
                                } else if (c>='0' && c<='9') {
                                        par[npar]=10*par[npar]+c-'0';
                                        break;
                                } else state=4;
                        case 4:
                                state=0;
                                switch(c) {
                                        case 'G': case '`':
                                                if (par[0]) par[0]--;
                                                gotoxy(par[0],y);
                                                break;
                                        case 'A':
                                                if (!par[0]) par[0]++;
                                                gotoxy(x,y-par[0]);
                                                break;
                                        case 'B': case 'e':
                                                if (!par[0]) par[0]++;
                                                gotoxy(x,y+par[0]);
                                                break;
                                        case 'C': case 'a':
                                                if (!par[0]) par[0]++;
                                                gotoxy(x+par[0],y);
                                                break;
                                        case 'D':
                                                if (!par[0]) par[0]++;
                                                gotoxy(x-par[0],y);
                                                break;
                                        case 'E':
                                                if (!par[0]) par[0]++;
                                                gotoxy(0,y+par[0]);
                                                break;
                                        case 'F':
                                                if (!par[0]) par[0]++;
                                                gotoxy(0,y-par[0]);
                                                break;
                                        case 'd':
                                                if (par[0]) par[0]--;
                                                gotoxy(x,par[0]);
                                                break;
                                        case 'H': case 'f':
                                                if (par[0]) par[0]--;
                                                if (par[1]) par[1]--;
                                                gotoxy(par[1],par[0]);
                                                break;
                                        case 'J':
                                                csi_J(par[0]);
                                                break;
                                        case 'K':
                                                csi_K(par[0]);
                                                break;
                                        case 'L':
                                                csi_L(par[0]);
                                                break;
                                        case 'M':
                                                csi_M(par[0]);
                                                break;
                                        case 'P':
                                                csi_P(par[0]);
                                                break;
                                        case '@':
                                                csi_at(par[0]);
                                                break;
                                        case 'm':
                                                csi_m();
                                                break;
                                        case 'r':
                                                if (par[0]) par[0]--;
                                                if (!par[1]) par[1]=lines;
                                                if (par[0] < par[1] &&
                                                    par[1] <= lines) {
                                                        top=par[0];
                                                        bottom=par[1];
                                                }
                                                break;
                                        case 's':
                                                save_cur();
                                                break;
                                        case 'u':
                                                restore_cur();
                                                break;
                                }
                }
        }
        set_cursor();
}

/*
 *  void con_init(void);
 *
 * This routine initalizes console interrupts, and does nothing
 * else. If you want the screen to clear, call tty_write with
 * the appropriate escape-sequece.
 */
void con_init(void)
{
        register unsigned char a;

        gotoxy(*(unsigned char *)(0x90000+510),*(unsigned char
*)(0x90000+511));
        set_trap_gate(0x21,&keyboard_interrupt);
        outb_p(inb_p(0x21)&0xfd,0x21);
        a=inb_p(0x61);
        outb_p(a|0x80,0x61);
        outb(a,0x61);
}

--
we are all just prisoners here of our own device
Last thing I remember I was running for the door
I had to find the passage back to the place I was before
Relax said the night man We are programmed to receive
You can check out any time you like but you can never leave

※ 来源:·荔园晨风BBS站 bbs.szu.edu.cn·[FROM: 192.168.35.5]


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