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/impl/lm_log_packet_transmitter.hpp

@@ -0,0 +1,74 @@
+/*
+ * 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/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+#include "lm_log_packet_transmitter_base.hpp"
+
+namespace ams::lm::impl {
+
+    class LogPacketTransmitter : public LogPacketTransmitterBase {
+        public:
+            LogPacketTransmitter(void *buffer, size_t buffer_size, FlushFunction flush_func, u8 severity, u8 verbosity, u64 process_id, bool head, bool tail)
+                : LogPacketTransmitterBase(buffer, buffer_size, flush_func, severity, verbosity, process_id, head, tail) { /* ... */ }
+
+            void PushLogSessionBegin() {
+                bool value = true;
+                this->PushDataChunk(LogDataChunkKey_LogSessionBegin, std::addressof(value), sizeof(value));
+            }
+
+            void PushLogSessionEnd() {
+                bool value = true;
+                this->PushDataChunk(LogDataChunkKey_LogSessionEnd, std::addressof(value), sizeof(value));
+            }
+
+            void PushTextLog(const char *str, size_t len) {
+                this->PushDataChunk(LogDataChunkKey_TextLog, str, len);
+            }
+
+            void PushLineNumber(u32 line) {
+                this->PushDataChunk(LogDataChunkKey_LineNumber, std::addressof(line), sizeof(line));
+            }
+
+            void PushFileName(const char *str, size_t len) {
+                this->PushDataChunk(LogDataChunkKey_FileName, str, len);
+            }
+
+            void PushFunctionName(const char *str, size_t len) {
+                this->PushDataChunk(LogDataChunkKey_FunctionName, str, len);
+            }
+
+            void PushModuleName(const char *str, size_t len) {
+                this->PushDataChunk(LogDataChunkKey_ModuleName, str, len);
+            }
+
+            void PushThreadName(const char *str, size_t len) {
+                this->PushDataChunk(LogDataChunkKey_ThreadName, str, len);
+            }
+
+            void PushLogPacketDropCount(u64 count) {
+                this->PushDataChunk(LogDataChunkKey_LineNumber, std::addressof(count), sizeof(count));
+            }
+
+            void PushUserSystemClock(s64 posix_time) {
+                this->PushDataChunk(LogDataChunkKey_LineNumber, std::addressof(posix_time), sizeof(posix_time));
+            }
+
+            void PushProcessName(const char *str, size_t len) {
+                this->PushDataChunk(LogDataChunkKey_ProcessName, str, len);
+            }
+    };
+
+}