OSDev.org

Code: Select all

main.c:(.text+0x1f): undefined reference to 'puts'

Code: Select all

drivers/char/char.a: could not read symbols: Bad value

Code: Select all

i586-elf-gcc -Wall -O -fstrength-reduce -fomit-frame-pointer -finline-functions -nostdinc -nodefaultlibs -fno-builtin -I $(INCLUDEDIR)

Code: Select all

#ifndef _PKERNL_SCREEN_H
#define _PKERNL_SCREEN_H

#define BLACK     0
#define BLUE      1
#define GREEN     2
#define CYAN      3
#define RED       4
#define MAGENTA   5
#define BROWN 	  6
#define LGREY 	  7
#define DGREY 	  8
#define LBLUE	  9
#define LGREEN   10
#define LCYAN    11
#define LRED     12
#define LMAGENTA 13
#define LBROWN	 14
#define WHITE	 15

extern void cls();
extern void putch(char c);
extern void putstr(const char *str);
extern void settextcolor(unsigned char forecolor, unsigned char backcolor);
extern void init_screen_d();

#endif //_PKERNL_SCREEN_H

Code: Select all

#include <pkernl/kernel.h>
#include <pkernl/types.h>

#include <pkernl/screen.h>

void main()
{
    //Initialization
    init_screen_d();
    putch('a');

    for (;;);
}

Code: Select all

#include <pkernl/screen.h>
#include <pkernl/string.h>
#include <asm/io.h>
/* These define our textpointer, our background and foreground
*  colors (attributes), and x and y cursor coordinates */
short *textmemptr;
int attrib = 0x0F;
int csr_x = 0, csr_y = 0;
/* Scrolls the screen */
void scroll(void)
{
    unsigned blank, temp;
    /* A blank is defined as a space... we need to give it
    *  backcolor too */
    blank = 0x20 | (attrib << 8);
    /* Row 25 is the end, this means we need to scroll up */
    if(csr_y >= 25)
    {
        /* Move the current text chunk that makes up the screen
        *  back in the buffer by a line */
        temp = csr_y - 25 + 1;
        memcpy (textmemptr, textmemptr + temp * 80, (25 - temp) * 80 * 2);
        /* Finally, we set the chunk of memory that occupies
        *  the last line of text to our 'blank' character */
        memsetw (textmemptr + (25 - temp) * 80, blank, 80);
        csr_y = 25 - 1;
    }
}
/* Updates the hardware cursor: the little blinking line
*  on the screen under the last character pressed! */
void move_csr(void)
{
    unsigned temp;
    /* The equation for finding the index in a linear
    *  chunk of memory can be represented by:
    *  Index = [(y * width) + x] */
    temp = csr_y * 80 + csr_x;
    /* This sends a command to indicies 14 and 15 in the
    *  CRT Control Register of the VGA controller. These
    *  are the high and low bytes of the index that show
    *  where the hardware cursor is to be 'blinking'. To
    *  learn more, look up some VGA specific
    *  programming documents. A great start to graphics:
    *  http://www.brackeen.com/home/vga */
    outportb(0x3D4, 14);
    outportb(0x3D5, temp >> 8);
    outportb(0x3D4, 15);
    outportb(0x3D5, temp);
}
/* Sets the forecolor and backcolor that we will use */
void settextcolor(unsigned char forecolor, unsigned char backcolor)
{
    /* Top 4 bytes are the background, bottom 4 bytes
    *  are the foreground color */
    attrib = (backcolor << 4) | (forecolor & 0x0F);
}
/* Clears the screen */
void cls()
{
    unsigned blank;
    int i;
    /* Again, we need the 'short' that will be used to
    *  represent a space with color */
    blank = 0x20 | (attrib << 8);
    /* Sets the entire screen to spaces in our current
    *  color */
    for(i = 0; i < 25; i++)
        memsetw (textmemptr + i * 80, blank, 80);
    /* Update out virtual cursor, and then move the
    *  hardware cursor */
    csr_x = 0;
    csr_y = 0;
    move_csr();
}
/* Puts a single character on the screen */
void putch(char c)
{
    short *where;
    unsigned att = attrib << 8;
    /* Handle a backspace, by moving the cursor back one space */
    if(c == 0x08)
        if(csr_x != 0) 
			csr_x--;
    /* Handles a tab by incrementing the cursor's x, but only
    *  to a point that will make it divisible by 8 */
    else if(c == 0x09)
        csr_x = (csr_x + 8) & ~(8 - 1);
    /* Handles a 'Carriage Return', which simply brings the
    *  cursor back to the margin */
    else if(c == '\r')
        csr_x = 0;
    /* We handle our newlines the way DOS and the BIOS do: we
    *  treat it as if a 'CR' was also there, so we bring the
    *  cursor to the margin and we increment the 'y' value */
    else if(c == '\n')
	{
        csr_x = 0;
        csr_y++;
    }
    /* Any character greater than and including a space, is a
    *  printable character. The equation for finding the index
    *  in a linear chunk of memory can be represented by:
    *  Index = [(y * width) + x] */
    else if(c >= ' ')
    {
        where = textmemptr + (csr_y * 80 + csr_x);
        *where = c | att;	/* Character AND attributes: color */
        csr_x++;
    }
    /* If the cursor has reached the edge of the screen's width, we
    *  insert a new line in there */
    if(csr_x >= 80)
    {
        csr_x = 0;
        csr_y++;
    }
    /* Scroll the screen if needed, and finally move the cursor */
    scroll();
    move_csr();
}
/* Uses the above routine to output a string... */
void putstr(const char *str)
{
    /*int i;
    for (i = 0; i < strlen(str); i++)
        putch(str[i]);*/
}
/* Sets our text-mode VGA pointer, then clears the screen for us */
void init_screen_d(void)
{
    textmemptr = (short*)0xB8000;
    cls();
}