add serial console support

Redirect int10 calls to serial console output.
Parse serial input and queue key events.
The serial console can work both as primary display
and in parallel to another vga display (splitmode).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 673 insertions, 0 deletions

diff --git a/src/sercon.c b/src/sercon.c
new file mode 100644
index 0000000..5d27051
--- /dev/null
+++ b/src/sercon.c
@@ -0,0 +1,673 @@
+// serial console support
+//
+// Copyright (C) 2016 Gerd Hoffmann <kraxel@redhat.com>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "biosvar.h" // SET_BDA
+#include "bregs.h" // struct bregs
+#include "stacks.h" // yield
+#include "output.h" // dprintf
+#include "util.h" // irqtimer_calc_ticks
+#include "string.h" // memcpy
+#include "romfile.h" // romfile_loadint
+#include "hw/serialio.h" // SEROFF_IER
+#include "cp437.h"
+
+static u8 video_rows(void)
+{
+    return GET_BDA(video_rows)+1;
+}
+
+static u8 video_cols(void)
+{
+    return GET_BDA(video_cols);
+}
+
+static u8 cursor_pos_col(void)
+{
+    u16 pos = GET_BDA(cursor_pos[0]);
+    return pos & 0xff;
+}
+
+static u8 cursor_pos_row(void)
+{
+    u16 pos = GET_BDA(cursor_pos[0]);
+    return (pos >> 8) & 0xff;
+}
+
+static void cursor_pos_set(u8 row, u8 col)
+{
+    u16 pos = ((u16)row << 8) | col;
+    SET_BDA(cursor_pos[0], pos);
+}
+
+/****************************************************************
+ * serial console output
+ ****************************************************************/
+
+VARLOW u16 sercon_port;
+VARLOW u8 sercon_split;
+VARLOW u8 sercon_enable;
+VARFSEG struct segoff_s sercon_real_vga_handler;
+
+/*
+ * We have a small output buffer here, for lazy output.  That allows
+ * to avoid a whole bunch of control sequences for pointless cursor
+ * moves, so when logging the output it'll be *alot* less cluttered.
+ *
+ * sercon_char/attr  is the actual output buffer.
+ * sercon_attr_last  is the most recent attribute sent to the terminal.
+ * sercon_col_last   is the most recent column sent to the terminal.
+ * sercon_row_last   is the most recent row sent to the terminal.
+ */
+VARLOW u8 sercon_attr_last;
+VARLOW u8 sercon_col_last;
+VARLOW u8 sercon_row_last;
+VARLOW u8 sercon_char;
+VARLOW u8 sercon_attr = 0x07;
+
+static VAR16 u8 sercon_cmap[8] = { '0', '4', '2', '6', '1', '5', '3', '7' };
+
+static int sercon_splitmode(void)
+{
+    return GET_LOW(sercon_split);
+}
+
+static void sercon_putchar(u8 chr)
+{
+    u16 addr = GET_LOW(sercon_port);
+    u32 end = irqtimer_calc_ticks(0x0a);
+
+#if 0
+    /* for visual control sequence debugging */
+    if (chr == '\x1b')
+        chr = '*';
+#endif
+
+    for (;;) {
+        u8 lsr = inb(addr+SEROFF_LSR);
+        if ((lsr & 0x60) == 0x60) {
+            // Success - can write data
+            outb(chr, addr+SEROFF_DATA);
+            break;
+        }
+        if (irqtimer_check(end)) {
+            break;
+        }
+        yield();
+    }
+}
+
+static void sercon_term_reset(void)
+{
+    sercon_putchar('\x1b');
+    sercon_putchar('c');
+}
+
+static void sercon_term_clear_screen(void)
+{
+    sercon_putchar('\x1b');
+    sercon_putchar('[');
+    sercon_putchar('2');
+    sercon_putchar('J');
+}
+
+static void sercon_term_no_linewrap(void)
+{
+    sercon_putchar('\x1b');
+    sercon_putchar('[');
+    sercon_putchar('?');
+    sercon_putchar('7');
+    sercon_putchar('l');
+}
+
+static void sercon_term_cursor_goto(u8 row, u8 col)
+{
+    row++; col++;
+    sercon_putchar('\x1b');
+    sercon_putchar('[');
+    sercon_putchar('0' + row / 10);
+    sercon_putchar('0' + row % 10);
+    sercon_putchar(';');
+    sercon_putchar('0' + col / 10);
+    sercon_putchar('0' + col % 10);
+    sercon_putchar('H');
+}
+
+static void sercon_term_set_color(u8 fg, u8 bg, u8 bold)
+{
+    sercon_putchar('\x1b');
+    sercon_putchar('[');
+    sercon_putchar('0');
+    if (fg != 7) {
+        sercon_putchar(';');
+        sercon_putchar('3');
+        sercon_putchar(GET_GLOBAL(sercon_cmap[fg & 7]));
+    }
+    if (bg != 0) {
+        sercon_putchar(';');
+        sercon_putchar('4');
+        sercon_putchar(GET_GLOBAL(sercon_cmap[bg & 7]));
+    }
+    if (bold) {
+        sercon_putchar(';');
+        sercon_putchar('1');
+    }
+    sercon_putchar('m');
+}
+
+static void sercon_set_attr(u8 attr)
+{
+    if (attr == GET_LOW(sercon_attr_last))
+        return;
+
+    SET_LOW(sercon_attr_last, attr);
+    sercon_term_set_color((attr >> 0) & 7,
+                          (attr >> 4) & 7,
+                          attr & 0x08);
+}
+
+static void sercon_print_utf8(u8 chr)
+{
+    u16 unicode = cp437_to_unicode(chr);
+
+    if (unicode < 0x7f) {
+        sercon_putchar(unicode);
+    } else if (unicode < 0x7ff) {
+        sercon_putchar(0xc0 | ((unicode >>  6) & 0x1f));
+        sercon_putchar(0x80 | ((unicode >>  0) & 0x3f));
+    } else {
+        sercon_putchar(0xe0 | ((unicode >> 12) & 0x0f));
+        sercon_putchar(0x80 | ((unicode >>  6) & 0x3f));
+        sercon_putchar(0x80 | ((unicode >>  0) & 0x3f));
+    }
+}
+
+static void sercon_cursor_pos_set(u8 row, u8 col)
+{
+    if (!sercon_splitmode()) {
+        cursor_pos_set(row, col);
+    } else {
+        /* let vgabios update cursor */
+    }
+}
+
+static void sercon_lazy_cursor_sync(void)
+{
+    u8 row = cursor_pos_row();
+    u8 col = cursor_pos_col();
+
+    if (GET_LOW(sercon_row_last) == row &&
+        GET_LOW(sercon_col_last) == col)
+        return;
+
+    if (col == 0 && GET_LOW(sercon_row_last) <= row) {
+        if (GET_LOW(sercon_col_last) != 0) {
+            sercon_putchar('\r');
+            SET_LOW(sercon_col_last, 0);
+        }
+        while (GET_LOW(sercon_row_last) < row) {
+            sercon_putchar('\n');
+            SET_LOW(sercon_row_last, GET_LOW(sercon_row_last)+1);
+        }
+        if (GET_LOW(sercon_row_last) == row &&
+            GET_LOW(sercon_col_last) == col)
+            return;
+    }
+
+    sercon_term_cursor_goto(row, col);
+    SET_LOW(sercon_row_last, row);
+    SET_LOW(sercon_col_last, col);
+}
+
+static void sercon_lazy_flush(void)
+{
+    u8 chr, attr;
+
+    chr = GET_LOW(sercon_char);
+    attr = GET_LOW(sercon_attr);
+    if (chr) {
+        sercon_set_attr(attr);
+        sercon_print_utf8(chr);
+        SET_LOW(sercon_col_last, GET_LOW(sercon_col_last) + 1);
+    }
+
+    sercon_lazy_cursor_sync();
+
+    SET_LOW(sercon_attr, 0x07);
+    SET_LOW(sercon_char, 0x00);
+}
+
+static void sercon_lazy_cursor_update(u8 row, u8 col)
+{
+    sercon_cursor_pos_set(row, col);
+    SET_LOW(sercon_row_last, row);
+    SET_LOW(sercon_col_last, col);
+}
+
+static void sercon_lazy_backspace(void)
+{
+    u8 col;
+
+    sercon_lazy_flush();
+    col = cursor_pos_col();
+    if (col > 0) {
+        sercon_putchar(8);
+        sercon_lazy_cursor_update(cursor_pos_row(), col-1);
+    }
+}
+
+static void sercon_lazy_cr(void)
+{
+    sercon_cursor_pos_set(cursor_pos_row(), 0);
+}
+
+static void sercon_lazy_lf(void)
+{
+    u8 row;
+
+    row = cursor_pos_row() + 1;
+    if (row >= video_rows()) {
+        /* scrolling up */
+        row = video_rows()-1;
+        if (GET_LOW(sercon_row_last) > 0) {
+            SET_LOW(sercon_row_last, GET_LOW(sercon_row_last) - 1);
+        }
+    }
+    sercon_cursor_pos_set(row, cursor_pos_col());
+}
+
+static void sercon_lazy_move_cursor(void)
+{
+    u8 col;
+
+    col = cursor_pos_col() + 1;
+    if (col >= video_cols()) {
+        sercon_lazy_cr();
+        sercon_lazy_lf();
+    } else {
+        sercon_cursor_pos_set(cursor_pos_row(), col);
+    }
+}
+
+static void sercon_lazy_putchar(u8 chr, u8 attr, u8 teletype)
+{
+    if (cursor_pos_row() != GET_LOW(sercon_row_last) ||
+        cursor_pos_col() != GET_LOW(sercon_col_last)) {
+        sercon_lazy_flush();
+    }
+
+    SET_LOW(sercon_char, chr);
+    if (teletype)
+        sercon_lazy_move_cursor();
+    else
+        SET_LOW(sercon_attr, attr);
+}
+
+/* Set video mode */
+static void sercon_1000(struct bregs *regs)
+{
+    u8 clearscreen = !(regs->al & 0x80);
+    u8 mode = regs->al & 0x7f;
+    u8 rows, cols;
+
+    if (!sercon_splitmode()) {
+        switch (mode) {
+        case 0x00:
+        case 0x01:
+        case 0x04: /* 320x200 */
+        case 0x05: /* 320x200 */
+            cols = 40;
+            rows = 25;
+            regs->al = 0x30;
+            break;
+        case 0x02:
+        case 0x03:
+        case 0x06: /* 640x200 */
+        case 0x07:
+        default:
+            cols = 80;
+            rows = 25;
+            regs->al = 0x30;
+            break;
+        }
+        cursor_pos_set(0, 0);
+        SET_BDA(video_mode, mode);
+        SET_BDA(video_cols, cols);
+        SET_BDA(video_rows, rows-1);
+        SET_BDA(cursor_type, 0x0007);
+    } else {
+        /* let vgabios handle mode init */
+    }
+
+    SET_LOW(sercon_enable, mode <= 0x07);
+    SET_LOW(sercon_col_last, 0);
+    SET_LOW(sercon_row_last, 0);
+    SET_LOW(sercon_attr_last, 0);
+
+    sercon_term_reset();
+    sercon_term_no_linewrap();
+    if (clearscreen)
+        sercon_term_clear_screen();
+}
+
+/* Set text-mode cursor shape */
+static void sercon_1001(struct bregs *regs)
+{
+    /* show/hide cursor? */
+    SET_BDA(cursor_type, regs->cx);
+}
+
+/* Set cursor position */
+static void sercon_1002(struct bregs *regs)
+{
+    sercon_cursor_pos_set(regs->dh, regs->dl);
+}
+
+/* Get cursor position */
+static void sercon_1003(struct bregs *regs)
+{
+    regs->cx = GET_BDA(cursor_type);
+    regs->dh = cursor_pos_row();
+    regs->dl = cursor_pos_col();
+}
+
+/* Scroll up window */
+static void sercon_1006(struct bregs *regs)
+{
+    sercon_lazy_flush();
+    if (regs->al == 0) {
+        /* clear rect, do only in case this looks like a fullscreen clear */
+        if (regs->ch == 0 &&
+            regs->cl == 0 &&
+            regs->dh == video_rows()-1 &&
+            regs->dl == video_cols()-1) {
+            sercon_set_attr(regs->bh);
+            sercon_term_clear_screen();
+        }
+    } else {
+        sercon_putchar('\r');
+        sercon_putchar('\n');
+    }
+}
+
+/* Read character and attribute at cursor position */
+static void sercon_1008(struct bregs *regs)
+{
+    regs->ah = 0x07;
+    regs->bh = ' ';
+}
+
+/* Write character and attribute at cursor position */
+static void sercon_1009(struct bregs *regs)
+{
+    u16 count = regs->cx;
+
+    if (count == 1) {
+        sercon_lazy_putchar(regs->al, regs->bl, 0);
+
+    } else if (regs->al == 0x20 &&
+               video_rows() * video_cols() == count &&
+               cursor_pos_row() == 0 &&
+               cursor_pos_col() == 0) {
+        /* override everything with spaces -> this is clear screen */
+        sercon_lazy_flush();
+        sercon_set_attr(regs->bl);
+        sercon_term_clear_screen();
+
+    } else {
+        sercon_lazy_flush();
+        sercon_set_attr(regs->bl);
+        while (count) {
+            sercon_print_utf8(regs->al);
+            count--;
+        }
+        sercon_term_cursor_goto(cursor_pos_row(),
+                                cursor_pos_col());
+    }
+}
+
+/* Teletype output */
+static void sercon_100e(struct bregs *regs)
+{
+    switch (regs->al) {
+    case 7:
+        sercon_putchar(0x07);
+        break;
+    case 8:
+        sercon_lazy_backspace();
+        break;
+    case '\r':
+        sercon_lazy_cr();
+        break;
+    case '\n':
+        sercon_lazy_lf();
+        break;
+    default:
+        sercon_lazy_putchar(regs->al, 0, 1);
+        break;
+    }
+}
+
+/* Get current video mode */
+static void sercon_100f(struct bregs *regs)
+{
+    regs->al = GET_BDA(video_mode);
+    regs->ah = GET_BDA(video_cols);
+}
+
+/* VBE 2.0 */
+static void sercon_104f(struct bregs *regs)
+{
+    if (!sercon_splitmode()) {
+        regs->ax = 0x0100;
+    } else {
+        // Disable sercon entry point on any vesa modeset
+        if (regs->al == 0x00)
+            SET_LOW(sercon_enable, 0);
+    }
+}
+
+static void sercon_10XX(struct bregs *regs)
+{
+    warn_unimplemented(regs);
+}
+
+void VISIBLE16
+handle_sercon(struct bregs *regs)
+{
+    if (!CONFIG_SERCON)
+        return;
+    if (!GET_LOW(sercon_port))
+        return;
+
+    switch (regs->ah) {
+    case 0x01:
+    case 0x02:
+    case 0x03:
+    case 0x08:
+    case 0x0f:
+        if (sercon_splitmode())
+            /* nothing, vgabios handles it */
+            return;
+    }
+
+    switch (regs->ah) {
+    case 0x00: sercon_1000(regs); break;
+    case 0x01: sercon_1001(regs); break;
+    case 0x02: sercon_1002(regs); break;
+    case 0x03: sercon_1003(regs); break;
+    case 0x06: sercon_1006(regs); break;
+    case 0x08: sercon_1008(regs); break;
+    case 0x09: sercon_1009(regs); break;
+    case 0x0e: sercon_100e(regs); break;
+    case 0x0f: sercon_100f(regs); break;
+    case 0x4f: sercon_104f(regs); break;
+    default:   sercon_10XX(regs); break;
+    }
+}
+
+void sercon_setup(void)
+{
+    if (!CONFIG_SERCON)
+        return;
+
+    struct segoff_s seabios, vgabios;
+    u16 addr;
+
+    addr = romfile_loadint("etc/sercon-port", 0);
+    if (!addr)
+        return;
+    dprintf(1, "sercon: using ioport 0x%x\n", addr);
+
+    vgabios = GET_IVT(0x10);
+    seabios = FUNC16(entry_10);
+    if (vgabios.seg != seabios.seg ||
+        vgabios.offset != seabios.offset) {
+        dprintf(1, "sercon: configuring in splitmode (vgabios %04x:%04x)\n",
+                vgabios.seg, vgabios.offset);
+        sercon_real_vga_handler = vgabios;
+        SET_LOW(sercon_split, 1);
+    } else {
+        dprintf(1, "sercon: configuring as primary display\n");
+        sercon_real_vga_handler = seabios;
+    }
+
+    SET_IVT(0x10, FUNC16(entry_sercon));
+    SET_LOW(sercon_port, addr);
+    outb(0x03, addr + SEROFF_LCR); // 8N1
+    outb(0x01, addr + 0x02);       // enable fifo
+}
+
+/****************************************************************
+ * serial input
+ ****************************************************************/
+
+VARLOW u8 rx_buf[16];
+VARLOW u8 rx_bytes;
+
+static VAR16 struct {
+    char seq[4];
+    u8   len;
+    u16  keycode;
+} termseq[] = {
+    { .seq = "OP",   .len = 2, .keycode = 0x3b00 },    // F1
+    { .seq = "OQ",   .len = 2, .keycode = 0x3c00 },    // F2
+    { .seq = "OR",   .len = 2, .keycode = 0x3d00 },    // F3
+    { .seq = "OS",   .len = 2, .keycode = 0x3e00 },    // F4
+
+    { .seq = "[15~", .len = 4, .keycode = 0x3f00 },    // F5
+    { .seq = "[17~", .len = 4, .keycode = 0x4000 },    // F6
+    { .seq = "[18~", .len = 4, .keycode = 0x4100 },    // F7
+    { .seq = "[19~", .len = 4, .keycode = 0x4200 },    // F8
+    { .seq = "[20~", .len = 4, .keycode = 0x4300 },    // F9
+    { .seq = "[21~", .len = 4, .keycode = 0x4400 },    // F10
+    { .seq = "[23~", .len = 4, .keycode = 0x5700 },    // F11
+    { .seq = "[24~", .len = 4, .keycode = 0x5800 },    // F12
+
+    { .seq = "[2~",  .len = 3, .keycode = 0x52e0 },    // insert
+    { .seq = "[3~",  .len = 3, .keycode = 0x53e0 },    // delete
+    { .seq = "[5~",  .len = 3, .keycode = 0x49e0 },    // page up
+    { .seq = "[6~",  .len = 3, .keycode = 0x51e0 },    // page down
+
+    { .seq = "[A",   .len = 2, .keycode = 0x48e0 },    // up
+    { .seq = "[B",   .len = 2, .keycode = 0x50e0 },    // down
+    { .seq = "[C",   .len = 2, .keycode = 0x4de0 },    // right
+    { .seq = "[D",   .len = 2, .keycode = 0x4be0 },    // left
+
+    { .seq = "[H",   .len = 2, .keycode = 0x47e0 },    // home
+    { .seq = "[F",   .len = 2, .keycode = 0x4fe0 },    // end
+};
+
+static void shiftbuf(int remove)
+{
+    int i, remaining;
+
+    remaining = GET_LOW(rx_bytes) - remove;
+    SET_LOW(rx_bytes, remaining);
+    for (i = 0; i < remaining; i++)
+        SET_LOW(rx_buf[i], GET_LOW(rx_buf[i + remove]));
+}
+
+static int cmpbuf(int seq)
+{
+    int chr, len;
+
+    len = GET_GLOBAL(termseq[seq].len);
+    if (GET_LOW(rx_bytes) < len + 1)
+        return 0;
+    for (chr = 0; chr < len; chr++)
+        if (GET_GLOBAL(termseq[seq].seq[chr]) != GET_LOW(rx_buf[chr + 1]))
+            return 0;
+    return 1;
+}
+
+static int findseq(void)
+{
+    int seq;
+
+    for (seq = 0; seq < ARRAY_SIZE(termseq); seq++)
+        if (cmpbuf(seq))
+            return seq;
+    return -1;
+}
+
+void
+sercon_check_event(void)
+{
+    if (!CONFIG_SERCON)
+        return;
+
+    u16 addr = GET_LOW(sercon_port);
+    u16 keycode;
+    u8 byte, count = 0;
+    int seq, chr;
+
+    // check to see if there is a active serial port
+    if (!addr)
+        return;
+    if (inb(addr + SEROFF_LSR) == 0xFF)
+        return;
+
+    // flush pending output
+    sercon_lazy_flush();
+
+    // read all available data
+    while (inb(addr + SEROFF_LSR) & 0x01) {
+        byte = inb(addr + SEROFF_DATA);
+        if (GET_LOW(rx_bytes) < sizeof(rx_buf)) {
+            SET_LOW(rx_buf[rx_bytes], byte);
+            SET_LOW(rx_bytes, GET_LOW(rx_bytes) + 1);
+            count++;
+        }
+    }
+
+    for (;;) {
+        // no (more) input data
+        if (!GET_LOW(rx_bytes))
+            return;
+
+        // lookup escape sequences
+        if (GET_LOW(rx_bytes) > 1 && GET_LOW(rx_buf[0]) == 0x1b) {
+            seq = findseq();
+            if (seq >= 0) {
+                enqueue_key(GET_GLOBAL(termseq[seq].keycode));
+                shiftbuf(GET_GLOBAL(termseq[seq].len) + 1);
+                continue;
+            }
+        }
+
+        // Seems we got a escape sequence we didn't recognise.
+        //  -> If we received data wait for more, maybe it is just incomplete.
+        if (GET_LOW(rx_buf[0]) == 0x1b && count)
+            return;
+
+        // Handle input as individual char.
+        chr = GET_LOW(rx_buf[0]);
+        keycode = ascii_to_keycode(chr);
+        if (keycode)
+            enqueue_key(keycode);
+        shiftbuf(1);
+    }
+}