vga.c File Reference

Virtual terminals in VGA text mode, when there is no framebuffer. More...

#include <core/system.h>
#include <cpu/io.h>
#include <mm/mm.h>
#include <dev/vt.h>

Go to the source code of this file.

Macros
#define	VGA_ROWS   25
#define	VGA_COLS   80

Functions
static void	vga_draw (int row, int col, struct vt_cell cell)
	Draws one cell of the screen.
static void	vga_cursor (int row, int col, int visible)
	Moves the cursor, or hides it.
int	vt_vga_probe (void)
	Says whether VGA text mode can be used.

Variables
static uint16_t *	vga = (uint16_t *) VMA(0xB8000)
static struct ioaddr	crtc
struct vt_display	vt_vga_display

Detailed Description

Virtual terminals in VGA text mode, when there is no framebuffer.

The screen is 80 columns by 25 rows of cells in memory at 0xB8000, each a character and its colours. The cursor is set through the CRT controller's ports (0x3D4 and 0x3D5). The virtual terminals (vt.c) draw through vt_vga_display.

Definition in file vga.c.

Macro Definition Documentation

VGA_COLS

#define VGA_COLS   80

Definition at line 16 of file vga.c.

VGA_ROWS

#define VGA_ROWS   25

Definition at line 15 of file vga.c.

Function Documentation

vga_cursor()

void vga_cursor ( int row, int col, int visible )

static

Moves the cursor, or hides it.

Definition at line 32 of file vga.c.

References crtc, io_out8(), VGA_COLS, vga_cursor(), and VGA_ROWS.

Referenced by vga_cursor().

vga_draw()

void vga_draw ( int row, int col, struct vt_cell cell )

static

Draws one cell of the screen.

Definition at line 26 of file vga.c.

References vt_cell::ch, vga, VGA_COLS, vga_draw(), and vt_vga_attr().

Referenced by vga_draw().

vt_vga_probe()

int vt_vga_probe

(

void

)

Says whether VGA text mode can be used.

It always can, on a PC.

Returns

0

Definition at line 48 of file vga.c.

References vt_vga_probe().

Referenced by vt_probe(), and vt_vga_probe().

Variable Documentation

crtc

struct ioaddr crtc

static

Initial value:

                   = {
    .addr = 0x3D4,
    .type = IOADDR_PORT,
}

Definition at line 20 of file vga.c.

Referenced by vga_cursor().

vga

uint16_t* vga = (uint16_t *) VMA(0xB8000)

static

Definition at line 18 of file vga.c.

vt_vga_display

struct vt_display vt_vga_display

Initial value:

                = {
    .name   = "VGA text mode",
    .rows   = VGA_ROWS,
    .cols   = VGA_COLS,
    .draw   = vga_draw,
    .cursor = vga_cursor,
}

Definition at line 53 of file vga.c.

Referenced by vt_probe().