Introduce libgsi, gsi_tool.

libgsi is a very small library to communicate critical gsi knowledge to
init and fs_mgr, to avoid hardcoding path names and constants.

gsi_tool is a shell wrapper to talk to gsid through binder.

gsid (currently in vold, will be moved shortly) is the daemon to manage
gsi installs.

Bug: 121210348
Test: N/A
Change-Id: I7942af56cb8e6ed69d28189bcf8d9806aa5e3e45

1 files changed, 68 insertions, 0 deletions

diff --git a/libgsi.cpp b/libgsi.cpp
new file mode 100644
index 0000000..4291389
--- /dev/null
+++ b/libgsi.cpp
@@ -0,0 +1,68 @@
+//
+// Copyright (C) 2019 The Android Open Source Project
+//
+// 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 "libgsi/libgsi.h"
+
+#include <unistd.h>
+
+#include <android-base/file.h>
+
+#include "file_paths.h"
+
+namespace android {
+namespace gsi {
+
+bool IsGsiRunning() {
+    return !access(kGsiBootedIndicatorFile, F_OK);
+}
+
+bool IsGsiInstalled() {
+    return !access(kGsiBootableFile, R_OK);
+}
+
+static bool CanBootIntoGsi(std::string* error) {
+    if (IsGsiInstalled()) {
+        *error = "not detected";
+        return false;
+    }
+    // :TODO: boot attempts
+    return true;
+}
+
+bool CanBootIntoGsi(std::string* metadata_file, std::string* error) {
+    if (!CanBootIntoGsi(error)) {
+        android::base::RemoveFileIfExists(kGsiBootedIndicatorFile);
+        android::base::RemoveFileIfExists(kGsiBootableFile);
+        return false;
+    }
+
+    *metadata_file = kGsiMetadata;
+    return true;
+}
+
+bool UninstallGsi() {
+    if (!android::base::RemoveFileIfExists(kGsiBootableFile)) {
+        return false;
+    }
+    return true;
+}
+
+bool MarkSystemAsGsi() {
+    return android::base::WriteStringToFile("1", kGsiBootedIndicatorFile);
+}
+
+}  // namespace gsi
+}  // namespace android