LogManager: implement system module, client api, logging api (#1617)

Some notes:

* Unless `atmosphere!enable_log_manager` is true, Nintendo's log manager will be used instead.
  * This prevents paying memory costs for LM when not enabling logging.
  * To facilitate this, Atmosphere's log manager has a different program id from Nintendo's.
  * `atmosphere!enable_htc` implies `atmosphere!enable_log_manager`.
* LogManager logs to tma, and the SD card (if `lm!enable_sd_card_logging` is true, which it is by default).
* Binary logs are saved to `lm!sd_card_log_output_directory`, which is `atmosphere/binlogs` by default.

libraries/libstratosphere/source/lm/lm_remote_log_service.cpp

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#include "lm_remote_log_service.hpp"
+#include "lm_service_name.hpp"
+
+namespace ams::lm {
+
+    namespace {
+
+        struct LmRemoteLogServiceTag;
+        using RemoteAllocator     = ams::sf::ExpHeapStaticAllocator<0x80, LmRemoteLogServiceTag>;
+        using RemoteObjectFactory = ams::sf::ObjectFactory<typename RemoteAllocator::Policy>;
+
+        class StaticAllocatorInitializer {
+            public:
+                StaticAllocatorInitializer() {
+                    RemoteAllocator::Initialize(lmem::CreateOption_None);
+                }
+        } g_static_allocator_initializer;
+
+    }
+
+    Result RemoteLogService::OpenLogger(sf::Out<sf::SharedPointer<::ams::lm::ILogger>> out, const sf::ClientProcessId &client_process_id) {
+        /* Send libnx command. */
+        ::Service logger_srv;
+        {
+            #define NX_SERVICE_ASSUME_NON_DOMAIN
+            R_TRY(serviceDispatch(&m_srv, 0,
+                .out_num_objects = 1,
+                .out_objects = &logger_srv,
+            ));
+            #undef NX_SERVICE_ASSUME_NON_DOMAIN
+        }
+
+        /* Open logger. */
+        out.SetValue(RemoteObjectFactory::CreateSharedEmplaced<::ams::lm::ILogger, RemoteLogger>(logger_srv));
+        return ResultSuccess();
+    }
+
+    sf::SharedPointer<ILogService> CreateLogService() {
+        ::Service srv;
+        R_ABORT_UNLESS(sm::GetService(std::addressof(srv), LogServiceName));
+
+        return RemoteObjectFactory::CreateSharedEmplaced<::ams::lm::ILogService, RemoteLogService>(srv);
+    }
+
+}