Fiasco(.OC) KDB UART driver

The KDB UART driver uses the Fiasco(.OC) kernel debugger console as backend
for input and output. This is useful in the case that only one UART is
available.

Fixes #665.

base-fiasco/run/env

@@ -76,8 +76,12 @@ proc bin_dir { } {
 	exit 1
 }
 
+set fiasco_serial_esc_arg "-serial_esc "
+
 proc build_boot_image {binaries} {
 
+	global fiasco_serial_esc_arg
+
 	#
 	# Collect contents of the ISO image
 	#
@@ -108,7 +112,7 @@ proc build_boot_image {binaries} {
 	puts $fh "default 0"
 	puts $fh "\ntitle Genode on L4/Fiasco"
 	puts $fh " kernel /fiasco/bootstrap -serial -modaddr=0x02000000"
-	puts $fh " module /fiasco/fiasco -serial -serial_esc -jdb_cmd=JH"
+	puts $fh " module /fiasco/fiasco -serial -jdb_cmd=JH $fiasco_serial_esc_arg"
 	puts $fh " module /fiasco/sigma0"
 	puts $fh " module /genode/core"
 	puts $fh " module /genode/config"

base-foc/run/env

@@ -136,9 +136,12 @@ proc build_boot_uimage { } {
 	}
 }
 
+set fiasco_serial_esc_arg "-serial_esc "
 
 proc build_boot_image_x86 {binaries} {
 
+	global fiasco_serial_esc_arg
+
 	copy_and_strip_binaries $binaries
 
 	set foc_targets { }
@@ -171,7 +174,7 @@ proc build_boot_image_x86 {binaries} {
 	puts $fh "default 0"
 	puts $fh "\ntitle Genode on Fiasco.OC"
 	puts $fh " kernel /fiasco/bootstrap -modaddr=0x01100000"
-	puts $fh " module /fiasco/fiasco -serial_esc"
+	puts $fh " module /fiasco/fiasco $fiasco_serial_esc_arg"
 	puts $fh " module /fiasco/sigma0"
 	puts $fh " module /genode/core"
 	puts $fh " module /genode/config"
@@ -187,6 +190,8 @@ proc build_boot_image_x86 {binaries} {
 
 proc build_boot_image_arm {binaries} {
 
+	global fiasco_serial_esc_arg
+
 	copy_and_strip_binaries $binaries
 
 	build "kernel sigma0 bootstrap"
@@ -198,7 +203,7 @@ proc build_boot_image_arm {binaries} {
 
 	puts $fh "modaddr 0x01100000\n"
 	puts $fh "entry    genode"
-	puts $fh "kernel   [fiasco] -serial_esc"
+	puts $fh "kernel   [fiasco] $fiasco_serial_esc_arg"
 	puts $fh "roottask genode/core"
 	puts $fh "module   genode/config"
 	foreach binary $binaries {

os/run/kdb_uart_drv.run

@@ -0,0 +1,89 @@
+#
+# \brief  Test for the KDB UART driver
+# \author Christian Prochaska
+# \date   2013-01-21
+#
+
+if {![have_spec foc] && ![have_spec fiasco]} {
+	puts "Run script only supports Fiasco/Fiasco.OC."; exit 0 }
+
+#
+# Build
+#
+
+build {
+	core init
+	drivers/timer
+	drivers/uart
+	test/terminal_echo
+}
+
+create_boot_directory
+
+#
+# Generate config
+#
+
+set config {
+<config verbose="yes">
+	<parent-provides>
+		<service name="ROM"/>
+		<service name="RAM"/>
+		<service name="IRQ"/>
+		<service name="IO_MEM"/>
+		<service name="IO_PORT"/>
+		<service name="CAP"/>
+		<service name="PD"/>
+		<service name="RM"/>
+		<service name="CPU"/>
+		<service name="LOG"/>
+		<service name="SIGNAL"/>
+	</parent-provides>
+	<default-route>
+		<any-service> <parent/> <any-child/> </any-service>
+	</default-route>
+	<start name="timer">
+		<resource name="RAM" quantum="1M"/>
+		<provides> <service name="Timer"/> </provides>
+	</start>
+	<start name="kdb_uart_drv">
+		<resource name="RAM" quantum="2M"/>
+		<provides>
+			<service name="Terminal"/>
+			<service name="Uart"/>
+		</provides>
+		<config>
+			<policy label="test-terminal_echo" uart="0" detect_size="yes"/>
+		</config>
+	</start>
+	<start name="test-terminal_echo">
+		<resource name="RAM" quantum="1M"/>
+	</start>
+</config>
+}
+
+install_config $config
+
+#
+# Boot modules
+#
+
+# generic modules
+set boot_modules {
+	core init timer
+	kdb_uart_drv
+	test-terminal_echo
+}
+
+set fiasco_serial_esc_arg ""
+
+build_boot_image $boot_modules
+
+#
+# Execute test
+#
+
+# qemu config
+append qemu_args " -m 128 -nographic "
+
+run_genode_until forever

os/src/drivers/uart/kdb/fiasco/target.mk

@@ -0,0 +1,3 @@
+REQUIRES = fiasco
+
+include $(PRG_DIR)/../target.inc

os/src/drivers/uart/kdb/foc/target.mk

@@ -0,0 +1,3 @@
+REQUIRES = foc
+
+include $(PRG_DIR)/../target.inc

os/src/drivers/uart/kdb/kdb_uart.h

@@ -0,0 +1,118 @@
+/*
+ * \brief  Fiasco(.OC) KDB UART driver
+ * \author Christian Prochaska
+ * \date   2013-03-07
+ */
+
+/*
+ * Copyright (C) 2013 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _KDB_UART_H_
+#define _KDB_UART_H_
+
+/* Fiasco.OC includes */
+namespace Fiasco {
+#include <l4/sys/kdebug.h>
+}
+
+/* Genode includes */
+#include <base/thread.h>
+#include <timer_session/connection.h>
+
+/* local includes */
+#include "uart_driver.h"
+
+using namespace Genode;
+
+
+class Kdb_uart : public Uart::Driver
+{
+	private:
+
+		signed char _buffered_char;
+		Lock        _kdb_read_lock;
+
+		enum { STACK_SIZE = 2*1024*sizeof(addr_t) };
+
+		class Char_avail_checker_thread : public Thread<STACK_SIZE>
+		{
+			private:
+
+				Uart::Driver              &_uart_driver;
+				Uart::Char_avail_callback &_char_avail_callback;
+
+			public:
+
+				Char_avail_checker_thread(Uart::Driver &uart_driver,
+				                          Uart::Char_avail_callback &char_avail_callback)
+				: _uart_driver(uart_driver),
+				  _char_avail_callback(char_avail_callback) { }
+
+				void entry()
+				{
+					Timer::Connection timer;
+
+					for(;;) {
+						if (_uart_driver.char_avail())
+							_char_avail_callback();
+						else
+							timer.msleep(20);
+					}
+				}
+
+		} _char_avail_checker_thread;
+
+	public:
+
+		/**
+		 * Constructor
+		 */
+		Kdb_uart(Uart::Char_avail_callback &callback)
+		: _buffered_char(-1),
+		  _char_avail_checker_thread(*this, callback)
+		{
+			_char_avail_checker_thread.start();
+		}
+
+		/***************************
+		 ** UART driver interface **
+		 ***************************/
+
+		void put_char(char c)
+		{
+			Fiasco::outchar(c);
+		}
+
+		bool char_avail()
+		{
+			Lock_guard<Lock> kdb_read_lock_guard(_kdb_read_lock);
+
+			if (_buffered_char == -1)
+				_buffered_char = Fiasco::l4kd_inchar();
+
+			return (_buffered_char != -1);
+		}
+
+		char get_char()
+		{
+			char result;
+
+			if (_buffered_char != -1) {
+				result = _buffered_char;
+				_buffered_char = -1;
+			} else
+				result = 0;
+
+			return result;
+		}
+
+		void baud_rate(int bits_per_second)
+		{
+		}
+};
+
+#endif /* _KDB_UART_H_ */

os/src/drivers/uart/kdb/main.cc

@@ -0,0 +1,70 @@
+/*
+ * \brief  Fiasco(.OC) KDB UART driver
+ * \author Christian Prochaska
+ * \date   2013-03-07
+ */
+
+/*
+ * Copyright (C) 2013 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <base/printf.h>
+#include <base/sleep.h>
+
+#include <cap_session/connection.h>
+
+#include "uart_component.h"
+
+#include "kdb_uart.h"
+
+
+int main(int argc, char **argv)
+{
+	using namespace Genode;
+
+	printf("--- Fiasco(.OC) KDB UART driver started ---\n");
+
+	/**
+	 * Factory used by 'Uart::Root' at session creation/destruction time
+	 */
+	struct Kdb_uart_driver_factory : Uart::Driver_factory
+	{
+		Kdb_uart *uart;
+
+		/**
+		 * Constructor
+		 */
+		Kdb_uart_driver_factory() : uart(0) { }
+
+		Uart::Driver *create(unsigned index, unsigned baudrate,
+		                     Uart::Char_avail_callback &callback)
+		{
+			/*
+			 * We assume the underlying kernel uses UART0
+			 */
+			if (index > 0)
+				throw Uart::Driver_factory::Not_available();
+
+			if (!uart)
+				uart = new (env()->heap()) Kdb_uart(callback);
+
+			return uart;
+		}
+
+		void destroy(Uart::Driver *driver) { /* TODO */ }
+
+	} driver_factory;
+
+	enum { STACK_SIZE = 2*1024*sizeof(addr_t) };
+	static Cap_connection cap;
+	static Rpc_entrypoint ep(&cap, STACK_SIZE, "uart_ep");
+
+	static Uart::Root uart_root(&ep, env()->heap(), driver_factory);
+	env()->parent()->announce(ep.manage(&uart_root));
+
+	sleep_forever();
+	return 0;
+}

os/src/drivers/uart/kdb/target.inc

@@ -0,0 +1,7 @@
+TARGET   = kdb_uart_drv
+SRC_CC   = main.cc
+LIBS     = base
+
+INC_DIR += $(PRG_DIR)/.. $(PRG_DIR)/../..
+
+vpath main.cc $(PRG_DIR)/..

os/src/drivers/uart/uart_component.h

@@ -98,8 +98,11 @@ namespace Uart {
 			 */
 			Size _detect_size()
 			{
-				/* set cursor position to the max */
-				_put_string("\033[1;199r\033[199;199H");
+				/*
+				 * Set cursor position to (hopefully) exceed the terminal
+				 * dimensions.
+				 */
+				_put_string("\033[1;199r\033[199;255H");
 
 				/* flush incoming characters */
 				for (; _driver.char_avail(); _driver.get_char());

os/src/test/terminal_echo/main.cc

@@ -17,6 +17,8 @@
 
 using namespace Genode;
 
+static const bool verbose = false;
+
 int main(int, char **)
 {
 	static Terminal::Connection terminal;
@@ -29,13 +31,17 @@ int main(int, char **)
 
 	terminal.read_avail_sigh(sig_rec.manage(&sig_ctx));
 
+	static const char *intro_text =
+		"--- Terminal echo test started - now you can type characters to be echoed. ---\n";
+	terminal.write(intro_text, strlen(intro_text) + 1);
+
 	for (;;) {
 
 		sig_rec.wait_for_signal();
 
 		int num_bytes = terminal.read(read_buffer, sizeof(read_buffer));
 
-		if (num_bytes)
+		if (verbose && (num_bytes > 0))
 			PDBG("got %d bytes", num_bytes);
 
 		for (int i = 0; i < num_bytes; i++)