/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
*
* ----------------------------------------------------------------------- */
/*
* arch/i386/boot/video-vesa.c
*
* VESA text modes
*/
#include "boot.h"
#include "video.h"
#include "vesa.h"
/* VESA information */
static struct vesa_general_info vginfo;
static struct vesa_mode_info vminfo;
__videocard video_vesa;
static void vesa_store_mode_params_graphics(void);
static int vesa_probe(void)
{
#if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID)
u16 ax, cx, di;
u16 mode;
addr_t mode_ptr;
struct mode_info *mi;
int nmodes = 0;
video_vesa.modes = GET_HEAP(struct mode_info, 0);
vginfo.signature = VBE2_MAGIC;
ax = 0x4f00;
di = (size_t)&vginfo;
asm(INT10
: "+a" (ax), "+D" (di), "=m" (vginfo)
: : "ebx", "ecx", "edx", "esi");
if (ax != 0x004f ||
vginfo.signature != VESA_MAGIC ||
vginfo.version < 0x0102)
return 0; /* Not present */
#endif /* CONFIG_VIDEO_VESA || CONFIG_FIRMWARE_EDID */
#ifdef CONFIG_VIDEO_VESA
set_fs(vginfo.video_mode_ptr.seg);
mode_ptr = vginfo.video_mode_ptr.off;
while ((mode = rdfs16(mode_ptr)) != 0xffff) {
mode_ptr += 2;
if (!heap_free(sizeof(struct mode_info)))
break; /* Heap full, can't save mode info */
if (mode & ~0x1ff)
continue;
memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
ax = 0x4f01;
cx = mode;
di = (size_t)&vminfo;
asm(INT10
: "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
: : "ebx", "edx", "esi");
if (ax != 0x004f)
continue;
if ((vminfo.mode_attr & 0x15) == 0x05) {
/* Text Mode, TTY BIOS supported,
supported by hardware */
mi = GET_HEAP(struct mode_info, 1);
mi->mode = mode + VIDEO_FIRST_VESA;
mi->x = vminfo.h_res;
mi->y = vminfo.v_res;
nmodes++;
} else if ((vminfo.mode_attr & 0x99) == 0x99) {
#ifdef CONFIG_FB
/* Graphics mode, color, linear frame buffer
supported -- register the mode but hide from
the menu. Only do this if framebuffer is
configured, however, otherwise the user will
be left without a screen. */
mi = GET_HEAP(struct mode_info, 1);
mi->mode = mode + VIDEO_FIRST_VESA;
mi->x = mi->y = 0;
nmodes++;
#endif
}
}
return nmodes;
#else
return 0;
#endif /* CONFIG_VIDEO_VESA */
}
static int vesa_set_mode(struct mode_info *mode)
{
u16 ax, bx, cx, di;
int is_graphic;
u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
ax = 0x4f01;
cx = vesa_mode;
di = (size_t)&vminfo;
asm(INT10
: "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
: : "ebx", "edx", "esi");
if (ax != 0x004f)
return -1;
if ((vminfo.mode_attr & 0x15) == 0x05) {
/* It's a supported text mode */
is_graphic = 0;
} else if ((vminfo.mode_attr & 0x99) == 0x99) {
/* It's a graphics mode with linear frame buffer */
is_graphic = 1;
vesa_mode |= 0x4000; /* Request linear frame buffer */
} else {
return -1; /* Invalid mode */
}
ax = 0x4f02;
bx = vesa_mode;
di = 0;
asm volatile(INT10
: "+a" (ax), "+b" (bx), "+D" (di)
: : "ecx", "edx", "esi");
if (ax != 0x004f)
return -1;
graphic_mode = is_graphic;
if (!is_graphic) {
/* Text mode */
force_x = mode->x;
force_y = mode->y;
do_restore = 1;
} else {
/* Graphics mode */
vesa_store_mode_params_graphics();
}
return 0;
}
/* Switch DAC to 8-bit mode */
static void vesa_dac_set_8bits(void)
{
u8 dac_size = 6;
/* If possible, switch the DAC to 8-bit mode */
if (vginfo.capabilities & 1) {
u16 ax, bx;
ax = 0x4f08;
bx = 0x0800;
asm volatile(INT10
: "+a" (ax), "+b" (bx)
: : "ecx", "edx", "esi", "edi");
if (ax == 0x004f)
dac_size = bx >> 8;
}
/* Set the color sizes to the DAC size, and offsets to 0 */
boot_params.screen_info.red_size = dac_size;
boot_params.screen_info.green_size = dac_size;
boot_params.screen_info.blue_size = dac_size;
boot_params.screen_info.rsvd_size = dac_size;
boot_params.screen_info.red_pos = 0;
boot_params.screen_info.green_pos = 0;
boot_params.screen_info.blue_pos = 0;
boot_params.screen_info.rsvd_pos = 0;
}
/* Save the VESA protected mode info */
static void vesa_store_pm_info(void)
{
u16 ax, bx, di, es;
ax = 0x4f0a;
bx = di = 0;
asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es"
: "=d" (es), "+a" (ax), "+b" (bx), "+D" (di)
: : "ecx", "esi");
if (ax != 0x004f)
return;
boot_params.screen_info.vesapm_seg = es;
boot_params.screen_info.vesapm_off = di;
}
/*
* Save video mode parameters for graphics mode
*/
static void vesa_store_mode_params_graphics(void)
{
/* Tell the kernel we're in VESA graphics mode */
boot_params.screen_info.orig_video_isVGA = 0x23;
/* Mode parameters */
boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
boot_params.screen_info.lfb_width = vminfo.h_res;
boot_params.screen_info.lfb_height = vminfo.v_res;
boot_params.screen_info.lfb_depth = vminfo.bpp;
boot_params.screen_info.pages = vminfo.image_planes;
boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
memcpy(&boot_params.screen_info.red_size,
&vminfo.rmask, 8);
/* General parameters */
boot_params.screen_info.lfb_size = vginfo.total_memory;
if (vminfo.bpp <= 8)
vesa_dac_set_8bits();
vesa_store_pm_info();
}
/*
* Save EDID information for the kernel; this is invoked, separately,
* after mode-setting.
*/
void vesa_store_edid(void)
{
#ifdef CONFIG_FIRMWARE_EDID
u16 ax, bx, cx, dx, di;
/* Apparently used as a nonsense token... */
memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
if (vginfo.version < 0x0200)
return; /* EDID requires VBE 2.0+ */
ax = 0x4f15; /* VBE DDC */
bx = 0x0000; /* Report DDC capabilities */
cx = 0; /* Controller 0 */
di = 0; /* ES:DI must be 0 by spec */
/* Note: The VBE DDC spec is different from the main VESA spec;
we genuinely have to assume all registers are destroyed here. */
asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es"
: "+a" (ax), "+b" (bx)
: "c" (cx), "D" (di)
: "esi");
if (ax != 0x004f)
return; /* No EDID */
/* BH = time in seconds to transfer EDD information */
/* BL = DDC level supported */
ax = 0x4f15; /* VBE DDC */
bx = 0x0001; /* Read EDID */
cx = 0; /* Controller 0 */
dx = 0; /* EDID block number */
di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */
asm(INT10
: "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info)
: "c" (cx), "D" (di)
: "esi");
#endif /* CONFIG_FIRMWARE_EDID */
}
__videocard video_vesa =
{
.card_name = "VESA",
.probe = vesa_probe,
.set_mode = vesa_set_mode,
.xmode_first = VIDEO_FIRST_VESA,
.xmode_n = 0x200,
};
