Import of the watch repository from Pebble

src/fw/debug/app_logging.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "util/attributes.h"
+#include "system/logging.h"
+#include "applib/app_logging.h"
+
+#include <stdint.h>
+
+#include "kernel/logging_private.h"
+#include "kernel/memory_layout.h"
+#include "kernel/util/stack_info.h"
+#include "services/common/comm_session/session.h"
+#include "syscall/syscall_internal.h"
+
+static const uint16_t APP_LOGGING_ENDPOINT = 2006;
+
+static AppLoggingMode s_app_logging_mode = AppLoggingDisabled;
+
+static const uint32_t MIN_STACK_FOR_SEND_DATA = 400;
+
+DEFINE_SYSCALL(void, sys_app_log, size_t length, void *log_buffer) {
+  if (PRIVILEGE_WAS_ELEVATED) {
+    syscall_assert_userspace_buffer(log_buffer, length);
+  }
+
+  AppLogBinaryMessage *message = log_buffer;
+
+  // First log to serial, we always do this.
+  kernel_pbl_log_serial(&message->log_msg, false);
+
+  // Now check to see if app logging is enabled over bluetooth.
+  if (s_app_logging_mode == AppLoggingDisabled) {
+    return;
+  }
+
+  // Then log to the app logging endpoint (if we have enough stack space)
+  uint32_t stack_space = stack_free_bytes();
+  if (stack_space > MIN_STACK_FOR_SEND_DATA) {
+    CommSession *session = comm_session_get_system_session();
+    if (session) {
+      comm_session_send_data(session, APP_LOGGING_ENDPOINT, (uint8_t*)log_buffer, length, COMM_SESSION_DEFAULT_TIMEOUT);
+    }
+  }
+}
+
+void app_log_protocol_msg_callback(CommSession *session, const uint8_t *data, const size_t length) {
+  typedef struct PACKED AppLogCommand {
+    uint8_t commandType;
+  } AppLogCommand;
+
+  enum AppLogCommandType {
+    APP_LOG_COMMAND_DISABLE_LOGGING = 0,
+    APP_LOG_COMMAND_ENABLE_LOGGING = 1,
+  };
+
+  AppLogCommand *command = (AppLogCommand *)data;
+  switch(command->commandType) {
+  case APP_LOG_COMMAND_ENABLE_LOGGING:
+    s_app_logging_mode = AppLoggingEnabled;
+    break;
+  case APP_LOG_COMMAND_DISABLE_LOGGING:
+    s_app_logging_mode = AppLoggingDisabled;
+    break;
+  default:
+    PBL_LOG(LOG_LEVEL_WARNING, "Invalid app log command 0x%x", command->commandType);
+  }
+}
+