/* ----------------------------------------------------------------------- *
*
* Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
* Copyright 2009 Intel Corporation; author: H. Peter Anvin
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
/*
* initvesa.c
*
* Query the VESA BIOS and select a 640x480x32 mode with local mapping
* support, if one exists.
*/
#include <inttypes.h>
#include <com32.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "vesa.h"
#include "mboot.h"
struct vesa_info vesa_info;
void set_graphics_mode(const struct multiboot_header *mbh,
struct multiboot_info *mbi)
{
com32sys_t rm;
uint16_t mode, bestmode, *mode_ptr;
struct vesa_general_info *gi;
struct vesa_mode_info *mi;
int pxf, bestpxf;
int wantx, wanty;
int err, besterr;
bool better;
addr_t viaddr;
/* Only do this if requested by the OS image */
if (!(mbh->flags & MULTIBOOT_VIDEO_MODE) || mbh->mode_type != 0)
return;
/* Allocate space in the bounce buffer for these structures */
gi = &((struct vesa_info *)__com32.cs_bounce)->gi;
mi = &((struct vesa_info *)__com32.cs_bounce)->mi;
memset(&rm, 0, sizeof rm);
memset(gi, 0, sizeof *gi);
gi->signature = VBE2_MAGIC; /* Get VBE2 extended data */
rm.eax.w[0] = 0x4F00; /* Get SVGA general information */
rm.edi.w[0] = OFFS(gi);
rm.es = SEG(gi);
__intcall(0x10, &rm, &rm);
if (rm.eax.w[0] != 0x004F)
return; /* Function call failed */
if (gi->signature != VESA_MAGIC)
return; /* No magic */
if (gi->version < 0x0102)
return; /* VESA 1.2+ required */
memcpy(&vesa_info.gi, gi, sizeof *gi);
/* Search for a suitable mode with a suitable color and memory model... */
mode_ptr = GET_PTR(gi->video_mode_ptr);
bestmode = 0;
bestpxf = 0;
wantx = mbh->width ? mbh->width : 0xffff;
wanty = mbh->height ? mbh->height : 0xffff;
besterr = wantx + wanty;
while ((mode = *mode_ptr++) != 0xFFFF) {
mode &= 0x1FF; /* The rest are attributes of sorts */
memset(mi, 0, sizeof *mi);
rm.eax.w[0] = 0x4F01; /* Get SVGA mode information */
rm.ecx.w[0] = mode;
rm.edi.w[0] = OFFS(mi);
rm.es = SEG(mi);
__intcall(0x10, &rm, &rm);
/* Must be a supported mode */
if (rm.eax.w[0] != 0x004f)
continue;
/* Must be an LFB color graphics mode supported by the hardware.
The bits tested are:
7 - linear frame buffer
4 - graphics mode
3 - color mode
1 - mode information available (mandatory in VBE 1.2+)
0 - mode supported by hardware
*/
if ((mi->mode_attr & 0x009b) != 0x009b)
continue;
/* We don't support multibank (interlaced memory) modes */
/*
* Note: The Bochs VESA BIOS (vbe.c 1.58 2006/08/19) violates the
* specification which states that banks == 1 for unbanked modes;
* fortunately it does report bank_size == 0 for those.
*/
if (mi->banks > 1 && mi->bank_size)
continue;
/* Must either be a packed-pixel mode or a direct color mode
(depending on VESA version ); must be a supported pixel format */
if (mi->bpp == 32 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
mi->bpos == 0)))
pxf = 32;
else if (mi->bpp == 24 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
mi->bpos == 0)))
pxf = 24;
else if (mi->bpp == 16 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 11 && mi->gpos == 5 &&
mi->bpos == 0)))
pxf = 16;
else if (mi->bpp == 15 &&
(mi->memory_layout == 4 ||
(mi->memory_layout == 6 && mi->rpos == 10 && mi->gpos == 5 &&
mi->bpos == 0)))
pxf = 15;
else
continue;
better = false;
err = abs(mi->h_res - wantx) + abs(mi->v_res - wanty);
#define IS_GOOD(mi, bestx, besty) \
((mi)->h_res >= (bestx) && (mi)->v_res >= (besty))
if (!bestpxf)
better = true;
else if (!IS_GOOD(&vesa_info.mi, wantx, wanty) &&
IS_GOOD(mi, wantx, wanty))
/* This matches criteria, which the previous one didn't */
better = true;
else if (IS_GOOD(&vesa_info.mi, wantx, wanty) &&
!IS_GOOD(mi, wantx, wanty))
/* This doesn't match criteria, and the previous one did */
better = false;
else if (err < besterr)
better = true;
else if (err == besterr && (pxf == (int)mbh->depth || pxf > bestpxf))
better = true;
if (better) {
bestmode = mode;
bestpxf = pxf;
memcpy(&vesa_info.mi, mi, sizeof *mi);
}
}
if (!bestpxf)
return; /* No mode found */
mi = &vesa_info.mi;
mode = bestmode;
/* Now set video mode */
rm.eax.w[0] = 0x4F02; /* Set SVGA video mode */
mode |= 0x4000; /* Request linear framebuffer */
rm.ebx.w[0] = mode;
__intcall(0x10, &rm, &rm);
if (rm.eax.w[0] != 0x004F)
return; /* Failed to set mode */
mbi->flags |= MB_INFO_VIDEO_INFO;
mbi->vbe_mode = mode;
viaddr = map_data(&vesa_info, sizeof vesa_info, 4, 0);
mbi->vbe_control_info = viaddr + offsetof(struct vesa_info, gi);
mbi->vbe_mode_info = viaddr + offsetof(struct vesa_info, mi);
/* Get the VBE 2.x PM entry point if supported */
rm.eax.w[0] = 0x4F0A;
rm.ebx.w[0] = 0;
__intcall(0x10, &rm, &rm);
if (rm.eax.w[0] == 0x004F) {
mbi->vbe_interface_seg = rm.es;
mbi->vbe_interface_off = rm.edi.w[0];
mbi->vbe_interface_len = rm.ecx.w[0];
}
/* Tell syslinux we changed video mode */
rm.eax.w[0] = 0x0017; /* Report video mode change */
/* In theory this should be:
rm.ebx.w[0] = (mi->mode_attr & 4) ? 0x0007 : 0x000f;
However, that would assume all systems that claim to handle text
output in VESA modes actually do that... */
rm.ebx.w[0] = 0x000f;
rm.ecx.w[0] = vesa_info.mi.h_res;
rm.edx.w[0] = vesa_info.mi.v_res;
__intcall(0x22, &rm, NULL);
}
