pc_platform_drv: introduce pc-specific driver

This driver observes a "system" ROM, as well as the acpi ROM to implement
reset functionality.

Ref genodelabs/genode#4578

repos/pc/recipes/src/pc_platform_drv/content.mk

@@ -0,0 +1,2 @@
+SRC_DIR = src/drivers/platform/pc
+include $(GENODE_DIR)/repos/os/recipes/src/platform_drv/content.inc

repos/pc/recipes/src/pc_platform_drv/hash

@@ -0,0 +1 @@
+2022-10-05 de4f9225c72915f78eb05e2e534d600d8c744789

repos/pc/recipes/src/pc_platform_drv/used_apis

@@ -0,0 +1,4 @@
+base
+os
+platform_session
+report_session

repos/pc/src/drivers/platform/pc/main.cc

@@ -0,0 +1,84 @@
+/*
+ * \brief  Platform driver for PC
+ * \author Stefan Kalkowski
+ * \date   2022-10-05
+ */
+
+/*
+ * Copyright (C) 2022 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+#include <base/component.h>
+
+#include <common.h>
+
+namespace Driver { struct Main; };
+
+struct Driver::Main
+{
+	Env                  & _env;
+	Attached_rom_dataspace _config_rom     { _env, "config"        };
+	Attached_rom_dataspace _acpi_rom       { _env, "acpi"          };
+	Attached_rom_dataspace _system_rom     { _env, "system"        };
+	Common                 _common         { _env, _config_rom     };
+	Signal_handler<Main>   _config_handler { _env.ep(), *this,
+	                                         &Main::_handle_config };
+	Signal_handler<Main>   _system_handler { _env.ep(), *this,
+	                                         &Main::_system_update };
+
+	void _handle_config();
+	void _reset();
+	void _system_update();
+
+	Main(Genode::Env & e)
+	: _env(e)
+	{
+		_config_rom.sigh(_config_handler);
+		_acpi_rom.sigh(_system_handler);
+		_system_rom.sigh(_system_handler);
+		_handle_config();
+		_system_update();
+		_common.announce_service();
+	}
+};
+
+
+void Driver::Main::_handle_config()
+{
+	_config_rom.update();
+	_common.handle_config(_config_rom.xml());
+}
+
+
+void Driver::Main::_reset()
+{
+	_acpi_rom.update();
+	_acpi_rom.xml().with_optional_sub_node("reset", [&] (Xml_node reset)
+	{
+		uint16_t const io_port = reset.attribute_value<uint16_t>("io_port", 0);
+		uint8_t  const value   = reset.attribute_value<uint8_t>("value",    0);
+
+		log("trigger reset by writing value ", value, " to I/O port ", Hex(io_port));
+
+		try {
+			Io_port_connection reset_port { _env, io_port, 1 };
+			reset_port.outb(io_port, value);
+		} catch (...) {
+			error("unable to access reset I/O port ", Hex(io_port)); }
+	});
+}
+
+
+void Driver::Main::_system_update()
+{
+	_system_rom.update();
+	if (_system_rom.xml().attribute_value("state", String<16>()) == "reset")
+		_reset();
+}
+
+
+void Component::construct(Genode::Env &env) {
+	static Driver::Main main(env); }

repos/pc/src/drivers/platform/pc/target.mk

@@ -0,0 +1,4 @@
+TARGET   = pc_platform_drv
+REQUIRES = x86
+
+include $(call select_from_repositories,src/drivers/platform/target.inc)