From 40e0ec918e728911c0dc3fb3f76d5c0de83dd702 Mon Sep 17 00:00:00 2001
From: Tao Bao <tbao@google.com>
Date: Thu, 5 Jan 2017 18:01:01 -0800
Subject: [PATCH] adb: Fix the 'adb reboot sideload' for A/B devices.

We used to write the command file (/cache/recovery/command) to trigger
the sideload mode. A/B devices don't support that (may not have /cache
paritition). This CL switches to using libbootloader_message which
writes the command to BCB (bootloader control block) instead.

Test: "adb root && adb reboot sideload" reboots sailfish into recovery
      sideload mode.

Change-Id: I158fd7cbcfa9a5d0609f1f684a2d03675217628f
---
 adb/Android.mk   |  1 +
 adb/services.cpp | 18 +++++++-----------
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/adb/Android.mk b/adb/Android.mk
index 16ed9911c..fab8c8780 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -330,6 +330,7 @@ LOCAL_STRIP_MODULE := keep_symbols
 LOCAL_STATIC_LIBRARIES := \
     libadbd \
     libbase \
+    libbootloader_message \
     libfs_mgr \
     libfec \
     libfec_rs \
diff --git a/adb/services.cpp b/adb/services.cpp
index 2fbc15a26..df1b134bf 100644
--- a/adb/services.cpp
+++ b/adb/services.cpp
@@ -39,6 +39,7 @@
 
 #if !ADB_HOST
 #include <android-base/properties.h>
+#include <bootloader_message/bootloader_message.h>
 #include <cutils/android_reboot.h>
 #include <private/android_logger.h>
 #endif
@@ -133,17 +134,12 @@ static bool reboot_service_impl(int fd, const char* arg) {
             return false;
         }
 
-        const char* const recovery_dir = "/cache/recovery";
-        const char* const command_file = "/cache/recovery/command";
-        // Ensure /cache/recovery exists.
-        if (adb_mkdir(recovery_dir, 0770) == -1 && errno != EEXIST) {
-            D("Failed to create directory '%s': %s", recovery_dir, strerror(errno));
-            return false;
-        }
-
-        bool write_status = android::base::WriteStringToFile(
-                auto_reboot ? "--sideload_auto_reboot" : "--sideload", command_file);
-        if (!write_status) {
+        const std::vector<std::string> options = {
+            auto_reboot ? "--sideload_auto_reboot" : "--sideload"
+        };
+        std::string err;
+        if (!write_bootloader_message(options, &err)) {
+            D("Failed to set bootloader message: %s", err.c_str());
             return false;
         }