diff options
Diffstat (limited to 'arch/x86/boot/video-vga.c')
| -rw-r--r-- | arch/x86/boot/video-vga.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/arch/x86/boot/video-vga.c b/arch/x86/boot/video-vga.c new file mode 100644 index 000000000..4816cb9cf --- /dev/null +++ b/arch/x86/boot/video-vga.c @@ -0,0 +1,286 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Common all-VGA modes + */ + +#include "boot.h" +#include "video.h" + +static struct mode_info vga_modes[] = { + { VIDEO_80x25, 80, 25, 0 }, + { VIDEO_8POINT, 80, 50, 0 }, + { VIDEO_80x43, 80, 43, 0 }, + { VIDEO_80x28, 80, 28, 0 }, + { VIDEO_80x30, 80, 30, 0 }, + { VIDEO_80x34, 80, 34, 0 }, + { VIDEO_80x60, 80, 60, 0 }, +}; + +static struct mode_info ega_modes[] = { + { VIDEO_80x25, 80, 25, 0 }, + { VIDEO_8POINT, 80, 43, 0 }, +}; + +static struct mode_info cga_modes[] = { + { VIDEO_80x25, 80, 25, 0 }, +}; + +static __videocard video_vga; + +/* Set basic 80x25 mode */ +static u8 vga_set_basic_mode(void) +{ + struct biosregs ireg, oreg; + u8 mode; + + initregs(&ireg); + + /* Query current mode */ + ireg.ax = 0x0f00; + intcall(0x10, &ireg, &oreg); + mode = oreg.al; + + if (mode != 3 && mode != 7) + mode = 3; + + /* Set the mode */ + ireg.ax = mode; /* AH=0: set mode */ + intcall(0x10, &ireg, NULL); + do_restore = 1; + return mode; +} + +static void vga_set_8font(void) +{ + /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */ + struct biosregs ireg; + + initregs(&ireg); + + /* Set 8x8 font */ + ireg.ax = 0x1112; + /* ireg.bl = 0; */ + intcall(0x10, &ireg, NULL); + + /* Use alternate print screen */ + ireg.ax = 0x1200; + ireg.bl = 0x20; + intcall(0x10, &ireg, NULL); + + /* Turn off cursor emulation */ + ireg.ax = 0x1201; + ireg.bl = 0x34; + intcall(0x10, &ireg, NULL); + + /* Cursor is scan lines 6-7 */ + ireg.ax = 0x0100; + ireg.cx = 0x0607; + intcall(0x10, &ireg, NULL); +} + +static void vga_set_14font(void) +{ + /* Set 9x14 font - 80x28 on VGA */ + struct biosregs ireg; + + initregs(&ireg); + + /* Set 9x14 font */ + ireg.ax = 0x1111; + /* ireg.bl = 0; */ + intcall(0x10, &ireg, NULL); + + /* Turn off cursor emulation */ + ireg.ax = 0x1201; + ireg.bl = 0x34; + intcall(0x10, &ireg, NULL); + + /* Cursor is scan lines 11-12 */ + ireg.ax = 0x0100; + ireg.cx = 0x0b0c; + intcall(0x10, &ireg, NULL); +} + +static void vga_set_80x43(void) +{ + /* Set 80x43 mode on VGA (not EGA) */ + struct biosregs ireg; + + initregs(&ireg); + + /* Set 350 scans */ + ireg.ax = 0x1201; + ireg.bl = 0x30; + intcall(0x10, &ireg, NULL); + + /* Reset video mode */ + ireg.ax = 0x0003; + intcall(0x10, &ireg, NULL); + + vga_set_8font(); +} + +/* I/O address of the VGA CRTC */ +u16 vga_crtc(void) +{ + return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4; +} + +static void vga_set_480_scanlines(void) +{ + u16 crtc; /* CRTC base address */ + u8 csel; /* CRTC miscellaneous output register */ + + crtc = vga_crtc(); + + out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */ + out_idx(0x0b, crtc, 0x06); /* Vertical total */ + out_idx(0x3e, crtc, 0x07); /* Vertical overflow */ + out_idx(0xea, crtc, 0x10); /* Vertical sync start */ + out_idx(0xdf, crtc, 0x12); /* Vertical display end */ + out_idx(0xe7, crtc, 0x15); /* Vertical blank start */ + out_idx(0x04, crtc, 0x16); /* Vertical blank end */ + csel = inb(0x3cc); + csel &= 0x0d; + csel |= 0xe2; + outb(csel, 0x3c2); +} + +static void vga_set_vertical_end(int lines) +{ + u16 crtc; /* CRTC base address */ + u8 ovfw; /* CRTC overflow register */ + int end = lines-1; + + crtc = vga_crtc(); + + ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40); + + out_idx(ovfw, crtc, 0x07); /* Vertical overflow */ + out_idx(end, crtc, 0x12); /* Vertical display end */ +} + +static void vga_set_80x30(void) +{ + vga_set_480_scanlines(); + vga_set_vertical_end(30*16); +} + +static void vga_set_80x34(void) +{ + vga_set_480_scanlines(); + vga_set_14font(); + vga_set_vertical_end(34*14); +} + +static void vga_set_80x60(void) +{ + vga_set_480_scanlines(); + vga_set_8font(); + vga_set_vertical_end(60*8); +} + +static int vga_set_mode(struct mode_info *mode) +{ + /* Set the basic mode */ + vga_set_basic_mode(); + + /* Override a possibly broken BIOS */ + force_x = mode->x; + force_y = mode->y; + + switch (mode->mode) { + case VIDEO_80x25: + break; + case VIDEO_8POINT: + vga_set_8font(); + break; + case VIDEO_80x43: + vga_set_80x43(); + break; + case VIDEO_80x28: + vga_set_14font(); + break; + case VIDEO_80x30: + vga_set_80x30(); + break; + case VIDEO_80x34: + vga_set_80x34(); + break; + case VIDEO_80x60: + vga_set_80x60(); + break; + } + + return 0; +} + +/* + * Note: this probe includes basic information required by all + * systems. It should be executed first, by making sure + * video-vga.c is listed first in the Makefile. + */ +static int vga_probe(void) +{ + static const char *card_name[] = { + "CGA/MDA/HGC", "EGA", "VGA" + }; + static struct mode_info *mode_lists[] = { + cga_modes, + ega_modes, + vga_modes, + }; + static int mode_count[] = { + ARRAY_SIZE(cga_modes), + ARRAY_SIZE(ega_modes), + ARRAY_SIZE(vga_modes), + }; + + struct biosregs ireg, oreg; + + initregs(&ireg); + + ireg.ax = 0x1200; + ireg.bl = 0x10; /* Check EGA/VGA */ + intcall(0x10, &ireg, &oreg); + +#ifndef _WAKEUP + boot_params.screen_info.orig_video_ega_bx = oreg.bx; +#endif + + /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */ + if (oreg.bl != 0x10) { + /* EGA/VGA */ + ireg.ax = 0x1a00; + intcall(0x10, &ireg, &oreg); + + if (oreg.al == 0x1a) { + adapter = ADAPTER_VGA; +#ifndef _WAKEUP + boot_params.screen_info.orig_video_isVGA = 1; +#endif + } else { + adapter = ADAPTER_EGA; + } + } else { + adapter = ADAPTER_CGA; + } + + video_vga.modes = mode_lists[adapter]; + video_vga.card_name = card_name[adapter]; + return mode_count[adapter]; +} + +static __videocard video_vga = { + .card_name = "VGA", + .probe = vga_probe, + .set_mode = vga_set_mode, +}; |