psplash-console.c

/*
 *  pslash - a lightweight framebuffer splashscreen for embedded devices.
 *
 *  Copyright (c) 2006 Matthew Allum <mallum@o-hand.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 */

#include "psplash.h"

/* Globals, needed for signal handling */
static int ConsoleFd    = -1;
static int VTNum        = -1;
static int VTNumInitial = -1;
static int Visible      = 1;

static void vt_request(int UNUSED(sig))
{
	ulog(LOG_DEBUG, "mark, visible:%i\n", Visible);

	if (Visible)
	{
		/* Allow Switch Away */
		if (ioctl(ConsoleFd, VT_RELDISP, 1) < 0)
			perror("Error cannot switch away from console");
		Visible = 0;

		/* FIXME:
		 * We likely now want to signal the main loop as to exit
		 * and we've now likely switched to the X tty. Note, this
		 * seems to happen anyway atm due to select() call getting
		 * a signal interuption error - not sure if this is really
		 * reliable however.
		 */
	}
	else
	{
		if (ioctl(ConsoleFd, VT_RELDISP, VT_ACKACQ))
			perror("Error can't acknowledge VT switch");
		Visible = 1;
		/* FIXME: need to schedule repaint some how ? */
	}
}

static void psplash_console_ignore_switches(void)
{
	struct sigaction act;
	struct vt_mode   vt_mode;

	if (ioctl(ConsoleFd, VT_GETMODE, &vt_mode) < 0)
	{
		perror("Error VT_SETMODE failed");
		return;
	}

	act.sa_handler = SIG_IGN;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	sigaction(SIGUSR1, &act, 0);

	vt_mode.mode   = VT_AUTO;
	vt_mode.relsig = 0;
	vt_mode.acqsig = 0;

	if (ioctl(ConsoleFd, VT_SETMODE, &vt_mode) < 0)
		perror("Error VT_SETMODE failed");
}

static void psplash_console_handle_switches(void)
{
	struct sigaction act;
	struct vt_mode   vt_mode;

	if (ioctl(ConsoleFd, VT_GETMODE, &vt_mode) < 0)
	{
		perror("Error VT_SETMODE failed");
		return;
	}

	act.sa_handler = vt_request;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	sigaction(SIGUSR1, &act, 0);

	vt_mode.mode   = VT_PROCESS;
	vt_mode.relsig = SIGUSR1;
	vt_mode.acqsig = SIGUSR1;

	if (ioctl(ConsoleFd, VT_SETMODE, &vt_mode) < 0)
		perror("Error VT_SETMODE failed");
}

void psplash_console_switch(void)
{
	char           vtname[10];
	int            fd;
	struct vt_stat vt_state;

	if ((fd = open("/dev/tty0", O_WRONLY, 0)) < 0)
	{
		perror("Error Cannot open /dev/tty0");
		return;
	}

	/* Find next free terminal */
	if ((ioctl(fd, VT_OPENQRY, &VTNum) < 0))
	{
		perror("Error unable to find a free virtual terminal");
		close(fd);
		return;
	}

	close(fd);

	sprintf(vtname, "/dev/tty%d", VTNum);

	if ((ConsoleFd = open(vtname, O_RDWR | O_NDELAY, 0)) < 0)
	{
		fprintf(stderr, "Error cannot open %s: %s\n", vtname, strerror(errno));
		return;
	}

	if (ioctl(ConsoleFd, VT_GETSTATE, &vt_state) == 0)
		VTNumInitial = vt_state.v_active;

	/* Switch to new free terminal */

	psplash_console_ignore_switches();

	if (ioctl(ConsoleFd, VT_ACTIVATE, VTNum) != 0)
		perror("Error VT_ACTIVATE failed");

	if (ioctl(ConsoleFd, VT_WAITACTIVE, VTNum) != 0)
		perror("Error VT_WAITACTIVE failed\n");

	psplash_console_handle_switches();

	if (ioctl(ConsoleFd, KDSETMODE, KD_GRAPHICS) < 0)
		perror("Error KDSETMODE KD_GRAPHICS failed\n");

	return;
}

void psplash_console_reset(void)
{
	int            fd;
	struct vt_stat vt_state;

	if (ConsoleFd < 0)
		return;

	/* Back to text mode */
	ioctl(ConsoleFd, KDSETMODE, KD_TEXT);

	psplash_console_ignore_switches();

	/* Attempt to switch back to initial console if were still active */
	ioctl(ConsoleFd, VT_GETSTATE, &vt_state);

	if (VTNum == vt_state.v_active)
	{
		if (VTNumInitial > -1)
		{
			ioctl(ConsoleFd, VT_ACTIVATE, VTNumInitial);
			ioctl(ConsoleFd, VT_WAITACTIVE, VTNumInitial);
			VTNumInitial = -1;
		}
	}

	/* Cleanup */

	close(ConsoleFd);

	if ((fd = open("/dev/tty0", O_RDWR | O_NDELAY, 0)) >= 0)
	{
		ioctl(fd, VT_DISALLOCATE, VTNum);
		close(fd);
	}

	return;
}