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-rw-r--r--arch/i386/boot/video.c456
1 files changed, 456 insertions, 0 deletions
diff --git a/arch/i386/boot/video.c b/arch/i386/boot/video.c
new file mode 100644
index 00000000000..3bb3573cd6a
--- /dev/null
+++ b/arch/i386/boot/video.c
@@ -0,0 +1,456 @@
+/* -*- 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.c
+ *
+ * Select video mode
+ */
+
+#include "boot.h"
+#include "video.h"
+#include "vesa.h"
+
+/*
+ * Mode list variables
+ */
+static struct card_info cards[]; /* List of cards to probe for */
+
+/*
+ * Common variables
+ */
+int adapter; /* 0=CGA/MDA/HGC, 1=EGA, 2=VGA+ */
+u16 video_segment;
+int force_x, force_y; /* Don't query the BIOS for cols/rows */
+
+int do_restore = 0; /* Screen contents changed during mode flip */
+int graphic_mode; /* Graphic mode with linear frame buffer */
+
+static void store_cursor_position(void)
+{
+ u16 curpos;
+ u16 ax, bx;
+
+ ax = 0x0300;
+ bx = 0;
+ asm(INT10
+ : "=d" (curpos), "+a" (ax), "+b" (bx)
+ : : "ecx", "esi", "edi");
+
+ boot_params.screen_info.orig_x = curpos;
+ boot_params.screen_info.orig_y = curpos >> 8;
+}
+
+static void store_video_mode(void)
+{
+ u16 ax, page;
+
+ /* N.B.: the saving of the video page here is a bit silly,
+ since we pretty much assume page 0 everywhere. */
+ ax = 0x0f00;
+ asm(INT10
+ : "+a" (ax), "=b" (page)
+ : : "ecx", "edx", "esi", "edi");
+
+ /* Not all BIOSes are clean with respect to the top bit */
+ boot_params.screen_info.orig_video_mode = ax & 0x7f;
+ boot_params.screen_info.orig_video_page = page;
+}
+
+/*
+ * Store the video mode parameters for later usage by the kernel.
+ * This is done by asking the BIOS except for the rows/columns
+ * parameters in the default 80x25 mode -- these are set directly,
+ * because some very obscure BIOSes supply insane values.
+ */
+static void store_mode_params(void)
+{
+ u16 font_size;
+ int x, y;
+
+ /* For graphics mode, it is up to the mode-setting driver
+ (currently only video-vesa.c) to store the parameters */
+ if (graphic_mode)
+ return;
+
+ store_cursor_position();
+ store_video_mode();
+
+ if (boot_params.screen_info.orig_video_mode == 0x07) {
+ /* MDA, HGC, or VGA in monochrome mode */
+ video_segment = 0xb000;
+ } else {
+ /* CGA, EGA, VGA and so forth */
+ video_segment = 0xb800;
+ }
+
+ set_fs(0);
+ font_size = rdfs16(0x485); /* Font size, BIOS area */
+ boot_params.screen_info.orig_video_points = font_size;
+
+ x = rdfs16(0x44a);
+ y = (adapter == ADAPTER_CGA) ? 25 : rdfs8(0x484)+1;
+
+ if (force_x)
+ x = force_x;
+ if (force_y)
+ y = force_y;
+
+ boot_params.screen_info.orig_video_cols = x;
+ boot_params.screen_info.orig_video_lines = y;
+}
+
+/* Probe the video drivers and have them generate their mode lists. */
+static void probe_cards(int unsafe)
+{
+ struct card_info *card;
+ static u8 probed[2];
+
+ if (probed[unsafe])
+ return;
+
+ probed[unsafe] = 1;
+
+ for (card = video_cards; card < video_cards_end; card++) {
+ if (card->unsafe == unsafe) {
+ if (card->probe)
+ card->nmodes = card->probe();
+ else
+ card->nmodes = 0;
+ }
+ }
+}
+
+/* Test if a mode is defined */
+int mode_defined(u16 mode)
+{
+ struct card_info *card;
+ struct mode_info *mi;
+ int i;
+
+ for (card = video_cards; card < video_cards_end; card++) {
+ mi = card->modes;
+ for (i = 0; i < card->nmodes; i++, mi++) {
+ if (mi->mode == mode)
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* Set mode (without recalc) */
+static int raw_set_mode(u16 mode)
+{
+ int nmode, i;
+ struct card_info *card;
+ struct mode_info *mi;
+
+ /* Drop the recalc bit if set */
+ mode &= ~VIDEO_RECALC;
+
+ /* Scan for mode based on fixed ID, position, or resolution */
+ nmode = 0;
+ for (card = video_cards; card < video_cards_end; card++) {
+ mi = card->modes;
+ for (i = 0; i < card->nmodes; i++, mi++) {
+ int visible = mi->x || mi->y;
+
+ if ((mode == nmode && visible) ||
+ mode == mi->mode ||
+ mode == (mi->y << 8)+mi->x)
+ return card->set_mode(mi);
+
+ if (visible)
+ nmode++;
+ }
+ }
+
+ /* Nothing found? Is it an "exceptional" (unprobed) mode? */
+ for (card = video_cards; card < video_cards_end; card++) {
+ if (mode >= card->xmode_first &&
+ mode < card->xmode_first+card->xmode_n) {
+ struct mode_info mix;
+ mix.mode = mode;
+ mix.x = mix.y = 0;
+ return card->set_mode(&mix);
+ }
+ }
+
+ /* Otherwise, failure... */
+ return -1;
+}
+
+/*
+ * Recalculate the vertical video cutoff (hack!)
+ */
+static void vga_recalc_vertical(void)
+{
+ unsigned int font_size, rows;
+ u16 crtc;
+ u8 ov;
+
+ set_fs(0);
+ font_size = rdfs8(0x485); /* BIOS: font size (pixels) */
+ rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */
+
+ rows *= font_size; /* Visible scan lines */
+ rows--; /* ... minus one */
+
+ crtc = vga_crtc();
+
+ out_idx((u8)rows, crtc, 0x12); /* Lower height register */
+ ov = in_idx(crtc, 0x07); /* Overflow register */
+ ov &= 0xbd;
+ ov |= (rows >> (8-1)) & 0x02;
+ ov |= (rows >> (9-6)) & 0x40;
+ out_idx(ov, crtc, 0x07);
+}
+
+/* Set mode (with recalc if specified) */
+static int set_mode(u16 mode)
+{
+ int rv;
+
+ /* Very special mode numbers... */
+ if (mode == VIDEO_CURRENT_MODE)
+ return 0; /* Nothing to do... */
+ else if (mode == NORMAL_VGA)
+ mode = VIDEO_80x25;
+ else if (mode == EXTENDED_VGA)
+ mode = VIDEO_8POINT;
+
+ rv = raw_set_mode(mode);
+ if (rv)
+ return rv;
+
+ if (mode & VIDEO_RECALC)
+ vga_recalc_vertical();
+
+ return 0;
+}
+
+static unsigned int get_entry(void)
+{
+ char entry_buf[4];
+ int i, len = 0;
+ int key;
+ unsigned int v;
+
+ do {
+ key = getchar();
+
+ if (key == '\b') {
+ if (len > 0) {
+ puts("\b \b");
+ len--;
+ }
+ } else if ((key >= '0' && key <= '9') ||
+ (key >= 'A' && key <= 'Z') ||
+ (key >= 'a' && key <= 'z')) {
+ if (len < sizeof entry_buf) {
+ entry_buf[len++] = key;
+ putchar(key);
+ }
+ }
+ } while (key != '\r');
+ putchar('\n');
+
+ if (len == 0)
+ return VIDEO_CURRENT_MODE; /* Default */
+
+ v = 0;
+ for (i = 0; i < len; i++) {
+ v <<= 4;
+ key = entry_buf[i] | 0x20;
+ v += (key > '9') ? key-'a'+10 : key-'0';
+ }
+
+ return v;
+}
+
+static void display_menu(void)
+{
+ struct card_info *card;
+ struct mode_info *mi;
+ char ch;
+ int i;
+
+ puts("Mode: COLSxROWS:\n");
+
+ ch = '0';
+ for (card = video_cards; card < video_cards_end; card++) {
+ mi = card->modes;
+ for (i = 0; i < card->nmodes; i++, mi++) {
+ int visible = mi->x && mi->y;
+ u16 mode_id = mi->mode ? mi->mode :
+ (mi->y << 8)+mi->x;
+
+ if (!visible)
+ continue; /* Hidden mode */
+
+ printf("%c %04X %3dx%-3d %s\n",
+ ch, mode_id, mi->x, mi->y, card->card_name);
+
+ if (ch == '9')
+ ch = 'a';
+ else if (ch == 'z' || ch == ' ')
+ ch = ' '; /* Out of keys... */
+ else
+ ch++;
+ }
+ }
+}
+
+#define H(x) ((x)-'a'+10)
+#define SCAN ((H('s')<<12)+(H('c')<<8)+(H('a')<<4)+H('n'))
+
+static unsigned int mode_menu(void)
+{
+ int key;
+ unsigned int sel;
+
+ puts("Press <ENTER> to see video modes available, "
+ "<SPACE> to continue, or wait 30 sec\n");
+
+ kbd_flush();
+ while (1) {
+ key = getchar_timeout();
+ if (key == ' ' || key == 0)
+ return VIDEO_CURRENT_MODE; /* Default */
+ if (key == '\r')
+ break;
+ putchar('\a'); /* Beep! */
+ }
+
+
+ for (;;) {
+ display_menu();
+
+ puts("Enter a video mode or \"scan\" to scan for "
+ "additional modes: ");
+ sel = get_entry();
+ if (sel != SCAN)
+ return sel;
+
+ probe_cards(1);
+ }
+}
+
+#ifdef CONFIG_VIDEO_RETAIN
+/* Save screen content to the heap */
+struct saved_screen {
+ int x, y;
+ int curx, cury;
+ u16 *data;
+} saved;
+
+static void save_screen(void)
+{
+ /* Should be called after store_mode_params() */
+ saved.x = boot_params.screen_info.orig_video_cols;
+ saved.y = boot_params.screen_info.orig_video_lines;
+ saved.curx = boot_params.screen_info.orig_x;
+ saved.cury = boot_params.screen_info.orig_y;
+
+ if (heap_free() < saved.x*saved.y*sizeof(u16)+512)
+ return; /* Not enough heap to save the screen */
+
+ saved.data = GET_HEAP(u16, saved.x*saved.y);
+
+ set_fs(video_segment);
+ copy_from_fs(saved.data, 0, saved.x*saved.y*sizeof(u16));
+}
+
+static void restore_screen(void)
+{
+ /* Should be called after store_mode_params() */
+ int xs = boot_params.screen_info.orig_video_cols;
+ int ys = boot_params.screen_info.orig_video_lines;
+ int y;
+ addr_t dst = 0;
+ u16 *src = saved.data;
+ u16 ax, bx, dx;
+
+ if (graphic_mode)
+ return; /* Can't restore onto a graphic mode */
+
+ if (!src)
+ return; /* No saved screen contents */
+
+ /* Restore screen contents */
+
+ set_fs(video_segment);
+ for (y = 0; y < ys; y++) {
+ int npad;
+
+ if (y < saved.y) {
+ int copy = (xs < saved.x) ? xs : saved.x;
+ copy_to_fs(dst, src, copy*sizeof(u16));
+ dst += copy*sizeof(u16);
+ src += saved.x;
+ npad = (xs < saved.x) ? 0 : xs-saved.x;
+ } else {
+ npad = xs;
+ }
+
+ /* Writes "npad" blank characters to
+ video_segment:dst and advances dst */
+ asm volatile("pushw %%es ; "
+ "movw %2,%%es ; "
+ "shrw %%cx ; "
+ "jnc 1f ; "
+ "stosw \n\t"
+ "1: rep;stosl ; "
+ "popw %%es"
+ : "+D" (dst), "+c" (npad)
+ : "bdSm" (video_segment),
+ "a" (0x07200720));
+ }
+
+ /* Restore cursor position */
+ ax = 0x0200; /* Set cursor position */
+ bx = 0; /* Page number (<< 8) */
+ dx = (saved.cury << 8)+saved.curx;
+ asm volatile(INT10
+ : "+a" (ax), "+b" (bx), "+d" (dx)
+ : : "ecx", "esi", "edi");
+}
+#else
+#define save_screen() ((void)0)
+#define restore_screen() ((void)0)
+#endif
+
+void set_video(void)
+{
+ u16 mode = boot_params.hdr.vid_mode;
+
+ RESET_HEAP();
+
+ store_mode_params();
+ save_screen();
+ probe_cards(0);
+
+ for (;;) {
+ if (mode == ASK_VGA)
+ mode = mode_menu();
+
+ if (!set_mode(mode))
+ break;
+
+ printf("Undefined video mode number: %x\n", mode);
+ mode = ASK_VGA;
+ }
+ vesa_store_edid();
+ store_mode_params();
+
+ if (do_restore)
+ restore_screen();
+}
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