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 000000000000..3bb3573cd6a1
--- /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();
+}