genode/repos/os/include/loader_session/loader_session.h

/*
 * \brief  Loader session interface
 * \author Christian Prochaska
 * \author Norman Feske
 * \date   2009-10-05
 */

/*
 * Copyright (C) 2009-2017 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.
 */

#ifndef _INCLUDE__LOADER_SESSION__LOADER_SESSION_H_
#define _INCLUDE__LOADER_SESSION__LOADER_SESSION_H_

#include <base/rpc.h>
#include <base/rpc_args.h>
#include <dataspace/capability.h>
#include <gui_session/client.h>
#include <pd_session/pd_session.h>
#include <base/signal.h>
#include <session/session.h>
#include <util/geometry.h>

namespace Loader {

	typedef Genode::Point<> Point;
	typedef Genode::Area<>  Area;
	typedef Genode::Rect<>  Rect;

	using Genode::Dataspace_capability;
	using Genode::Signal_context_capability;
	using Genode::Ram_quota;
	using Genode::Cap_quota;

	struct Session;
}


struct Loader::Session : Genode::Session
{
	/*
	 * Resolve ambiguity of 'size_t' type when using 'loader_session.h'
	 * together with libc headers.
	 */
	typedef Genode::size_t size_t;

	/*
	 * Exception types
	 */
	struct Exception : Genode::Exception { };
	struct View_does_not_exist       : Exception { };
	struct Rom_module_does_not_exist : Exception { };

	typedef Genode::Rpc_in_buffer<64>  Name;
	typedef Genode::Rpc_in_buffer<128> Path;

	/**
	 * \noapi
	 */
	static const char *service_name() { return "Loader"; }

	static constexpr unsigned CAP_QUOTA = 2;

	virtual ~Session() { }

	/**
	 * Allocate dataspace to be used as ROM module by the loaded subsystem
	 *
	 * \param name  designated name of the ROM module
	 * \param size  size of ROM module
	 *
	 * \return Dataspace_capability  dataspace that contains the backing
	 *                               store of the ROM module
	 *
	 * The content of the dataspace is made visible to the loaded subsystem
	 * not before 'commit_rom_module' has been called. This two-step
	 * procedure enables the client to update the content of the ROM module
	 * during the lifetime of the session by subsequently calling dataspace
	 * with the same name as argument. Each time, a new dataspace is
	 * allocated but not yet presented to the loaded subsystem. When
	 * calling 'commit_rom_module', the most recently allocated dataspace
	 * becomes visible. The server frees intermediate dataspaces that are
	 * no longer used.
	 */
	virtual Dataspace_capability alloc_rom_module(Name const &name, size_t size) = 0;

	/**
	 * Expose ROM module to loaded subsystem
	 *
	 * \throw Rom_module_does_not_exist  if the ROM module name wasn't
	 *                                   allocated beforehand
	 */
	virtual void commit_rom_module(Name const &name) = 0;

	/**
	 * Define capability quota assigned to the subsystem
	 */
	virtual void cap_quota(Cap_quota) = 0;

	/**
	 * Define RAM quota assigned to the subsystem
	 *
	 * The quantum specified must be in the bounds of the quota attached
	 * the session. Note that RAM resources used for ROM modules are
	 * accounted, too. If ROM modules are modified at runtime by subsequent
	 * calls of 'alloc_rom_module', the resources needed for the respective
	 * ROM modules are doubled.
	 *
	 * If 'ram_quota' is not called prior calling 'start', all available
	 * session resources will be assigned to the subsystem.
	 */
	virtual void ram_quota(Ram_quota quantum) = 0;

	/**
	 * Constrain size of the nitpicker buffer used by the subsystem
	 *
	 * Calling this method prior 'start()' enables the virtualization
	 * of the nitpicker session interface.
	 */
	virtual void constrain_geometry(Area size) = 0;

	/**
	 * Set the parent view of the subsystem's view.
	 *
	 * If 'parent_view' is not called prior calling 'start', the
	 * subsystem's view will not have a parent view.
	 */
	virtual void parent_view(Gui::View_capability view) = 0;

	/**
	 * Register signal handler notified at creation time of the first view
	 */
	virtual void view_ready_sigh(Signal_context_capability sigh) = 0;

	/**
	 * Register signal handler notified when a failure occurs in the
	 * loaded subsystem.
	 *
	 * This signal is delivered if any child process of the subsystem
	 * produces an unresolvable page fault, exists, or triggers a CPU
	 * exception. (e.g., division by zero) For more information about
	 * the possible types of faults, please refer to the documentation of
	 * 'Rm_session::fault_handler' and 'Cpu_session::exception_handler'.
	 *
	 * This method should not be called after the 'start' method.
	 */
	virtual void fault_sigh(Signal_context_capability sigh) = 0;

	/**
	 * Start subsystem
	 *
	 * \throw Rom_module_does_not_exist  if the specified binary could
	 *                                   not obtained as ROM module
	 */
	virtual void start(Name const &binary, Name const &label = "") = 0;

	/**
	 * Set view geometry and buffer offset
	 */
	virtual void view_geometry(Rect rect, Point offset) = 0;

	/**
	 * Return view size as initialized by the loaded subsystem
	 */
	virtual Area view_size() const = 0;


	/*******************
	 ** RPC interface **
	 *******************/

	GENODE_RPC(Rpc_alloc_rom_module, Dataspace_capability, alloc_rom_module,
	                                 Name const &, size_t);
	GENODE_RPC_THROW(Rpc_commit_rom_module, void, commit_rom_module,
	                 GENODE_TYPE_LIST(Rom_module_does_not_exist),
	                 Name const &);
	GENODE_RPC(Rpc_cap_quota, void, cap_quota, Cap_quota);
	GENODE_RPC(Rpc_ram_quota, void, ram_quota, Ram_quota);
	GENODE_RPC(Rpc_constrain_geometry, void, constrain_geometry, Area);
	GENODE_RPC(Rpc_parent_view, void, parent_view, Gui::View_capability);
	GENODE_RPC(Rpc_view_ready_sigh, void, view_ready_sigh, Signal_context_capability);
	GENODE_RPC(Rpc_fault_sigh, void, fault_sigh, Signal_context_capability);
	GENODE_RPC_THROW(Rpc_start, void, start,
	                 GENODE_TYPE_LIST(Rom_module_does_not_exist),
	                 Name const &, Name const &);
	GENODE_RPC_THROW(Rpc_view_geometry, void, view_geometry,
	                 GENODE_TYPE_LIST(View_does_not_exist),
	                 Rect, Point);
	GENODE_RPC_THROW(Rpc_view_size, Area, view_size,
	                 GENODE_TYPE_LIST(View_does_not_exist));

	GENODE_RPC_INTERFACE(Rpc_alloc_rom_module, Rpc_commit_rom_module,
	                     Rpc_cap_quota, Rpc_ram_quota, Rpc_constrain_geometry,
	                     Rpc_parent_view, Rpc_view_ready_sigh, Rpc_fault_sigh,
	                     Rpc_start, Rpc_view_geometry, Rpc_view_size);
};

#endif /* _INCLUDE__LOADER_SESSION__LOADER_SESSION_H_ */