[linux] Add console

Add linux console using stdin/out. Configure the attached terminal for
readline use.

Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/Makefile

@@ -73,7 +73,7 @@ SRCDIRS		+= drivers/block
 SRCDIRS		+= drivers/nvs
 SRCDIRS		+= drivers/bitbash
 SRCDIRS		+= drivers/infiniband
-SRCDIRS		+= interface/pxe interface/efi interface/smbios
+SRCDIRS		+= interface/pxe interface/efi interface/smbios interface/linux
 SRCDIRS		+= tests
 SRCDIRS		+= crypto crypto/axtls crypto/matrixssl
 SRCDIRS		+= hci hci/commands hci/tui

src/config/config.c

@@ -82,6 +82,9 @@ REQUIRE_OBJECT ( syslog );
 #ifdef CONSOLE_EFI
 REQUIRE_OBJECT ( efi_console );
 #endif
+#ifdef CONSOLE_LINUX
+REQUIRE_OBJECT ( linux_console );
+#endif
 
 /*
  * Drag in all requested network protocols

src/config/defaults/linux.h

@@ -7,6 +7,8 @@
  *
  */
 
+#define CONSOLE_LINUX
+
 #define IMAGE_SCRIPT
 
 #endif /* CONFIG_DEFAULTS_LINUX_H */

src/interface/linux/linux_console.c

@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.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 of the
+ * License, or 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+FILE_LICENCE(GPL2_OR_LATER);
+
+/** @file
+ *
+ * Linux console implementation.
+ *
+ */
+
+#include <console.h>
+
+#include <ipxe/init.h>
+#include <ipxe/keys.h>
+#include <linux_api.h>
+
+#include <linux/termios.h>
+#include <asm/errno.h>
+
+static void linux_console_putchar(int c)
+{
+	/* write to stdout */
+	if (linux_write(1, &c, 1) != 1)
+		DBG("linux_console write failed (%s)\n", linux_strerror(linux_errno));
+}
+
+static int linux_console_getchar()
+{
+	char c;
+
+	/* read from stdin */
+	if (linux_read(0, &c, 1) < 0) {
+		DBG("linux_console read failed (%s)\n", linux_strerror(linux_errno));
+		return 0;
+	}
+	/* backspace seems to be returned as ascii del, map it here */
+	if (c == 0x7f)
+		return KEY_BACKSPACE;
+	else
+		return c;
+}
+
+static int linux_console_iskey()
+{
+	struct pollfd pfd;
+	pfd.fd = 0;
+	pfd.events = POLLIN;
+
+	/* poll for data to be read on stdin */
+	if (linux_poll(&pfd, 1, 0) == -1) {
+		DBG("linux_console poll failed (%s)\n", linux_strerror(linux_errno));
+		return 0;
+	}
+
+	if (pfd.revents & POLLIN)
+		return 1;
+	else
+		return 0;
+}
+
+struct console_driver linux_console __console_driver = {
+	.disabled = 0,
+	.putchar = linux_console_putchar,
+	.getchar = linux_console_getchar,
+	.iskey = linux_console_iskey,
+};
+
+static int linux_tcgetattr(int fd, struct termios *termios_p)
+{
+	return linux_ioctl(fd, TCGETS, termios_p);
+}
+
+static int linux_tcsetattr(int fd, int optional_actions, const struct termios *termios_p)
+{
+	unsigned long int cmd;
+
+	switch (optional_actions)
+	{
+		case TCSANOW:
+			cmd = TCSETS;
+			break;
+		case TCSADRAIN:
+			cmd = TCSETSW;
+			break;
+		case TCSAFLUSH:
+			cmd = TCSETSF;
+			break;
+		default:
+			linux_errno = EINVAL;
+			return -1;
+	}
+
+	return linux_ioctl(fd, cmd, termios_p);
+}
+
+/** Saved termios attributes */
+static struct termios saved_termios;
+
+/** Setup the terminal for our use */
+static void linux_console_startup(void)
+{
+	struct termios t;
+
+	if (linux_tcgetattr(0, &t)) {
+		DBG("linux_console tcgetattr failed (%s)", linux_strerror(linux_errno));
+		return;
+	}
+
+	saved_termios = t;
+
+	/* Disable canonical mode and echo. Let readline handle that */
+	t.c_lflag &= ~(ECHO | ICANON);
+	/* stop ^C from sending a signal */
+	t.c_cc[VINTR] = 0;
+
+	if (linux_tcsetattr(0, TCSAFLUSH, &t))
+		DBG("linux_console tcsetattr failed (%s)", linux_strerror(linux_errno));
+}
+
+/** Restores original terminal attributes on shutdown */
+static void linux_console_shutdown(int flags __unused)
+{
+	if (linux_tcsetattr(0, TCSAFLUSH, &saved_termios))
+		DBG("linux_console tcsetattr failed (%s)", linux_strerror(linux_errno));
+}
+
+struct startup_fn linux_console_startup_fn __startup_fn(STARTUP_EARLY) = {
+	.startup = linux_console_startup,
+	.shutdown = linux_console_shutdown,
+};