vesa.c File Reference

The VESA framebuffer: the linear framebuffer that the boot loader set up, as /dev/fb0. More...

#include <core/system.h>
#include <dev/fbdev.h>
#include <fs/devfs.h>
#include <video/vesa.h>
#include <mm/vm.h>

Go to the source code of this file.

Functions
static ssize_t	fbdev_vesa_write (struct fbdev *fb, off_t offset, struct iobuf *io)
	Writes to the framebuffer at offset, as much as fits before its end.
static int	fbdev_vesa_map (struct fbdev *fb, struct vm_space *vm_space, struct vm_entry *vm_entry)
	Maps the framebuffer, or part of it, into a process's address space.
static int	fbdev_vesa_prope (int i, struct fbdev *fb)
	Sets up the framebuffer from the mode the boot loader chose: maps it into the kernel's address space, and fills in its screen information for ioctl().

Variables
static char *	vmem = (char *) ARCH_VESA_BASE
static struct vm_entry	vesa_vm
static size_t	len = 0
static struct fb_fix_screeninfo	vesa_fix_screeninfo
static struct fb_var_screeninfo	vesa_var_screeninfo
struct fbdev	fbdev_vesa

Detailed Description

The VESA framebuffer: the linear framebuffer that the boot loader set up, as /dev/fb0.

The boot loader chose the video mode and gave its description (a VBE mode info block). This driver maps the framebuffer into the kernel's address space, at ARCH_VESA_BASE, and describes it with Linux's framebuffer structures. The mode can't be changed. A process can write to the framebuffer, or map it into its own address space (a shared mapping only).

Definition in file vesa.c.

Function Documentation

fbdev_vesa_map()

int fbdev_vesa_map ( struct fbdev * fb, struct vm_space * vm_space, struct vm_entry * vm_entry )

static

Maps the framebuffer, or part of it, into a process's address space.

Only a shared mapping is possible (ENOTSUP for a private one), and it must lie within the framebuffer (ENXIO otherwise).

Definition at line 52 of file vesa.c.

References fb, fb_size, fbdev_vesa_map(), vm_entry::flags, vm_entry::off, vm_entry::paddr, PAGE_ROUND, vm_entry::size, vesa_vm, vm_map(), and VM_SHARED.

Referenced by fbdev_vesa_map(), and fbdev_vesa_prope().

fbdev_vesa_prope()

int fbdev_vesa_prope ( int i, struct fbdev * fb )

static

Sets up the framebuffer from the mode the boot loader chose: maps it into the kernel's address space, and fills in its screen information for ioctl().

Returns 0, or a negative errno if it can't be mapped, and then the framebuffer stays unusable (its writes fail).

Definition at line 73 of file vesa.c.

References mode_info_block::bits_per_pixel, mode_info_block::blue_field_position, mode_info_block::blue_mask_size, fbdev::data, fb, fbdev_vesa_map(), fbdev_vesa_prope(), fbdev_vesa_write(), fbdev::fix_screeninfo, vm_entry::flags, mode_info_block::green_field_position, mode_info_block::green_mask_size, kvm_space, len, mode_info_block::lin_bytes_per_scanline, fbdev::map, fbdev_vesa::mode_info, vm_entry::paddr, mode_info_block::phys_base_ptr, printk(), fbdev::probe, mode_info_block::red_field_position, mode_info_block::red_mask_size, vm_entry::size, fbdev::var_screeninfo, vesa_fix_screeninfo, vesa_var_screeninfo, vesa_vm, VM_KRW, vm_map(), fbdev::write, mode_info_block::x_resolution, and mode_info_block::y_resolution.

Referenced by fbdev_vesa_prope().

fbdev_vesa_write()

ssize_t fbdev_vesa_write ( struct fbdev * fb, off_t offset, struct iobuf * io )

static

Writes to the framebuffer at offset, as much as fits before its end.

Returns how much was written, 0 past the end.

Definition at line 37 of file vesa.c.

References fb, fbdev_vesa_write(), iobuf_in(), len, MIN, and iobuf::resid.

Referenced by fbdev_vesa_prope(), and fbdev_vesa_write().

Variable Documentation

fbdev_vesa

struct fbdev fbdev_vesa

Initial value:

           = {
    .probe = fbdev_vesa_prope,
    .write = fbdev_vesa_write,
    .map   = fbdev_vesa_map,
}

Definition at line 141 of file vesa.c.

len

size_t len = 0

static

Definition at line 27 of file vesa.c.

Referenced by fbdev_vesa_prope(), and fbdev_vesa_write().

vesa_fix_screeninfo

struct fb_fix_screeninfo vesa_fix_screeninfo

static

Initial value:

                              = {
    .id = "VESA FB",
}

Definition at line 29 of file vesa.c.

Referenced by fbdev_vesa_prope().

vesa_var_screeninfo

struct fb_var_screeninfo vesa_var_screeninfo

static

Definition at line 33 of file vesa.c.

Referenced by fbdev_vesa_prope().

vesa_vm

struct vm_entry vesa_vm

static

Initial value:

                     = {
    .base = ARCH_VESA_BASE,
}

Definition at line 22 of file vesa.c.

Referenced by fbdev_vesa_map(), and fbdev_vesa_prope().

vmem

char* vmem = (char *) ARCH_VESA_BASE

static

Definition at line 20 of file vesa.c.