diff options
Diffstat (limited to 'com32/mboot/initvesa.c')
| -rw-r--r-- | com32/mboot/initvesa.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/com32/mboot/initvesa.c b/com32/mboot/initvesa.c new file mode 100644 index 00000000..5452648d --- /dev/null +++ b/com32/mboot/initvesa.c @@ -0,0 +1,219 @@ +/* ----------------------------------------------------------------------- * + * + * 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 */ + pxf = 0; /* Not usable */ + + 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; + + better = false; + + err = abs(mi->h_res - wantx) + abs(mi->v_res - wanty); + + if (!bestpxf) + better = true; + else if ((vesa_info.mi.h_res < wantx || vesa_info.mi.v_res < wantx) && + mi->h_res >= wantx && mi->v_res >= wanty) + /* This matches criteria, which the previous one didn't */ + better = true; + 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); +} |