black_hole: provide ROM service

Ref #4419

repos/os/recipes/pkg/black_hole/runtime

@@ -7,6 +7,7 @@
 		<event/>
 		<nic/>
 		<uplink/>
+		<rom/>
 	</provides>
 
 	<config>
@@ -16,6 +17,7 @@
 		<event/>
 		<nic/>
 		<uplink/>
+		<rom/>
 	</config>
 
 	<content>

repos/os/recipes/pkg/test-black_hole/runtime

@@ -30,6 +30,7 @@
 		<start name="black_hole" caps="100">
 			<resource name="RAM" quantum="1M"/>
 			<provides>
+				<service name="ROM"/>
 				<service name="Uplink"/>
 				<service name="Nic"/>
 				<service name="Event"/>
@@ -38,6 +39,7 @@
 				<service name="Audio_out"/>
 			</provides>
 			<config>
+				<rom/>
 				<uplink/>
 				<nic/>
 				<event/>
@@ -57,16 +59,17 @@
 		<start name="test-black_hole" caps="100">
 			<resource name="RAM" quantum="10M"/>
 			<route>
-				<service name="Uplink">    <child name="black_hole"/> </service>
+				<service name="ROM" label="any_label"> <child name="black_hole"/> </service>
-				<service name="Nic">       <child name="black_hole"/> </service>
+				<service name="Uplink">                <child name="black_hole"/> </service>
-				<service name="Event">     <child name="black_hole"/> </service>
+				<service name="Nic">                   <child name="black_hole"/> </service>
-				<service name="Capture">   <child name="black_hole"/> </service>
+				<service name="Event">                 <child name="black_hole"/> </service>
-				<service name="Audio_in">  <child name="black_hole"/> </service>
+				<service name="Capture">               <child name="black_hole"/> </service>
-				<service name="Audio_out"> <child name="black_hole"/> </service>
+				<service name="Audio_in">              <child name="black_hole"/> </service>
-				<service name="ROM">       <parent/> </service>
+				<service name="Audio_out">             <child name="black_hole"/> </service>
-				<service name="PD">        <parent/> </service>
+				<service name="ROM" >                  <parent/> </service>
-				<service name="LOG">       <parent/> </service>
+				<service name="PD">                    <parent/> </service>
-				<service name="CPU">       <parent/> </service>
+				<service name="LOG">                   <parent/> </service>
+				<service name="CPU">                   <parent/> </service>
 			</route>
 		</start>
 

repos/os/src/server/black_hole/README

@@ -10,6 +10,7 @@ in the configuration of the component:
 * Event
 * Nic
 * Uplink
+* ROM
 
 <config>
 	<audio_in/>
@@ -18,4 +19,5 @@ in the configuration of the component:
 	<event/>
 	<nic/>
 	<uplink/>
+	<rom/>
 </config>

repos/os/src/server/black_hole/config.xsd

@@ -4,6 +4,7 @@
 	<xs:element name="config">
 		<xs:complexType>
 			<xs:choice minOccurs="0" maxOccurs="unbounded">
+				<xs:element name="rom"/>
 				<xs:element name="uplink"/>
 				<xs:element name="nic"/>
 				<xs:element name="event"/>

repos/os/src/server/black_hole/main.cc

@@ -27,6 +27,7 @@
 #include "event.h"
 #include "nic.h"
 #include "uplink.h"
+#include "rom.h"
 
 
 /***************
@@ -47,6 +48,7 @@ struct Black_hole::Main
 	Genode::Constructible<Event_root>      event_root     { };
 	Genode::Constructible<Nic_root>        nic_root       { };
 	Genode::Constructible<Uplink_root>     uplink_root    { };
+	Genode::Constructible<Rom_root>        rom_root       { };
 
 	Main(Genode::Env &env) : env(env)
 	{
@@ -56,12 +58,10 @@ struct Black_hole::Main
 			audio_in_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*audio_in_root));
 		}
-
 		if (_config_rom.xml().has_sub_node("audio_out")) {
 			audio_out_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*audio_out_root));
 		}
-
 		if (_config_rom.xml().has_sub_node("capture")) {
 			capture_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*capture_root));
@@ -70,16 +70,18 @@ struct Black_hole::Main
 			event_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*event_root));
 		}
-
 		if (_config_rom.xml().has_sub_node("nic")) {
 			nic_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*nic_root));
 		}
-
 		if (_config_rom.xml().has_sub_node("uplink")) {
 			uplink_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*uplink_root));
 		}
+		if (_config_rom.xml().has_sub_node("rom")) {
+			rom_root.construct(env, heap);
+			env.parent().announce(env.ep().manage(*rom_root));
+		}
 	}
 };
 

repos/os/src/server/black_hole/rom.h

@@ -0,0 +1,91 @@
+/*
+ * \brief  ROM session component and root
+ * \author Martin Stein
+ * \date   2022-03-11
+ */
+
+/*
+ * 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.
+ */
+
+#ifndef _ROM_H_
+#define _ROM_H_
+
+/* base includes */
+#include <base/attached_ram_dataspace.h>
+#include <rom_session/rom_session.h>
+#include <root/component.h>
+
+namespace Black_hole {
+
+	using namespace Genode;
+
+	class  Rom_session;
+	class  Rom_root;
+}
+
+
+class Black_hole::Rom_session : public Session_object<Genode::Rom_session>
+{
+	private:
+
+		enum { RAM_DS_SIZE = 16 };
+
+		Env                     &_env;
+		Attached_ram_dataspace   _ram_ds  { _env.ram(), _env.rm(), RAM_DS_SIZE };
+
+	public:
+
+		Rom_session(Env             &env,
+		            Resources const &resources,
+		            Label     const &label,
+		            Diag      const &diag)
+		:
+			Session_object(env.ep(), resources, label, diag),
+			_env { env }
+		{
+			copy_cstring(_ram_ds.local_addr<char>(), "<empty/>", RAM_DS_SIZE);
+		}
+
+		Rom_dataspace_capability dataspace() override
+		{
+			return
+				static_cap_cast<Rom_dataspace>(
+					static_cap_cast<Dataspace>(_ram_ds.cap()));
+		}
+
+		void sigh(Signal_context_capability /* sigh */) override { }
+};
+
+
+class Black_hole::Rom_root : public Root_component<Rom_session>
+{
+	private:
+
+		Env &_env;
+
+	protected:
+
+		Rom_session *_create_session(const char *args) override
+		{
+			return new (md_alloc())
+				Rom_session {
+					_env, session_resources_from_args(args),
+					session_label_from_args(args),
+					session_diag_from_args(args) };
+		}
+
+	public:
+
+		Rom_root(Env       &env,
+		         Allocator &alloc)
+		:
+			Root_component<Rom_session> { &env.ep().rpc_ep(), &alloc },
+			_env                        { env }
+		{ }
+};
+
+#endif /* _ROM_H_ */

repos/os/src/test/black_hole/main.cc

@@ -19,6 +19,8 @@
 #include <base/component.h>
 #include <base/heap.h>
 #include <util/reconstructible.h>
+#include <rom_session/connection.h>
+#include <base/attached_rom_dataspace.h>
 
 /* os includes */
 #include <event_session/connection.h>
@@ -38,6 +40,7 @@ namespace Black_hole_test {
 	class Uplink_test;
 	class Capture_test;
 	class Event_test;
+	class Rom_test;
 	class Main;
 }
 
@@ -295,6 +298,35 @@ class Black_hole_test::Event_test
 };
 
 
+class Black_hole_test::Rom_test
+{
+	private:
+
+		Env                    &_env;
+		Attached_rom_dataspace  _rom_ds   { _env, "any_label" };
+		bool                    _finished { false };
+
+	public:
+
+		Rom_test(Env &env)
+		:
+			_env { env }
+		{
+			String<16> const str { Cstring { _rom_ds.local_addr<char>() } };
+			if (str != "<empty/>") {
+				class Unexpected_rom_content { };
+				throw Unexpected_rom_content { };
+			}
+			_finished = true;
+		}
+
+		bool finished() const
+		{
+			return _finished;
+		}
+};
+
+
 class Black_hole_test::Main
 {
 	private:
@@ -308,6 +340,7 @@ class Black_hole_test::Main
 		Uplink_test            _uplink_test    { _env, _heap, _signal_handler };
 		Capture_test           _capture_test   { _env };
 		Event_test             _event_test     { _env };
+		Rom_test               _rom_test       { _env };
 
 		void _handle_signal()
 		{
@@ -321,7 +354,8 @@ class Black_hole_test::Main
 			if (_nic_test.finished() &&
 			    _uplink_test.finished() &&
 			    _capture_test.finished() &&
-			    _event_test.finished()) {
+			    _event_test.finished() &&
+			    _rom_test.finished()) {
 
 				log("Finished");
 			}