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-rw-r--r--arch/x86/boot/video-vga.c286
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,
+};