From ee6a0b5a8b2949ae442fc5c930f5a65f1598f685 Mon Sep 17 00:00:00 2001
From: Connor O'Brien <connoro@google.com>
Date: Fri, 28 Sep 2018 12:53:02 -0700
Subject: [PATCH] Add statically linked boot HAL impl in recovery

The default Treble boot HAL implementation currently can only work in
recovery on devices that specifically build their libhardware
implementation as a shared library for recovery.

This CL adds the option to statically link the libhardware
implementation in recovery instead of finding it using
hw_get_module(). This new approach allows devices that define
PRODUCT_STATIC_BOOT_CONTROL_HAL to begin using the Treble HAL in
recovery without requiring device-specific changes.

Test: adb sideload succeeds
Bug: 78598708
Change-Id: I7e1651fad64c2e55da256a164d2875956f68fb67
Signed-off-by: Connor O'Brien <connoro@google.com>
---
 boot/1.0/default/Android.mk      | 29 +++++++++++++++++++++++++++++
 boot/1.0/default/BootControl.cpp | 22 +++++++++++++++++++++-
 2 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 boot/1.0/default/Android.mk

diff --git a/boot/1.0/default/Android.mk b/boot/1.0/default/Android.mk
new file mode 100644
index 0000000000..cd4b499ae6
--- /dev/null
+++ b/boot/1.0/default/Android.mk
@@ -0,0 +1,29 @@
+# TODO(connoro): Remove this file once we eliminate existing usage of
+# PRODUCT_STATIC_BOOT_CONTROL_HAL
+
+LOCAL_PATH := $(call my-dir)
+
+ifneq ($(strip $(PRODUCT_STATIC_BOOT_CONTROL_HAL)),)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := android.hardware.boot@1.0-impl-wrapper.recovery
+LOCAL_MODULE_CLASS := SHARED_LIBRARIES
+LOCAL_MULTILIB := first
+ifeq ($(TARGET_IS_64_BIT),true)
+LOCAL_MODULE_PATH := $(TARGET_RECOVERY_ROOT_OUT)/system/lib64/hw
+else
+LOCAL_MODULE_PATH := $(TARGET_RECOVERY_ROOT_OUT)/system/lib/hw
+endif
+LOCAL_SRC_FILES := BootControl.cpp
+LOCAL_CFLAGS := -DBOOT_CONTROL_RECOVERY
+LOCAL_SHARED_LIBRARIES := \
+    liblog.recovery \
+    libhidlbase.recovery \
+    libhidltransport.recovery \
+    libhardware.recovery \
+    libutils.recovery \
+    android.hardware.boot@1.0.recovery
+LOCAL_STATIC_LIBRARIES := $(PRODUCT_STATIC_BOOT_CONTROL_HAL)
+include $(BUILD_SHARED_LIBRARY)
+
+endif
diff --git a/boot/1.0/default/BootControl.cpp b/boot/1.0/default/BootControl.cpp
index 9a900767d7..e36407fe26 100644
--- a/boot/1.0/default/BootControl.cpp
+++ b/boot/1.0/default/BootControl.cpp
@@ -21,6 +21,10 @@
 #include <hardware/boot_control.h>
 #include "BootControl.h"
 
+#ifdef BOOT_CONTROL_RECOVERY
+extern const hw_module_t HAL_MODULE_INFO_SYM;
+#endif
+
 namespace android {
 namespace hardware {
 namespace boot {
@@ -92,7 +96,23 @@ Return<void> BootControl::getSuffix(uint32_t slot, getSuffix_cb _hidl_cb)  {
     return Void();
 }
 
+#ifdef BOOT_CONTROL_RECOVERY
+IBootControl* HIDL_FETCH_IBootControl(const char * /* hal */) {
+    boot_control_module_t* module;
 
+    // For devices that don't build a standalone libhardware bootctrl impl for recovery,
+    // we simulate the hw_get_module() by accessing it from the current process directly.
+    const hw_module_t* hw_module = &HAL_MODULE_INFO_SYM;
+    if (!hw_module ||
+        strcmp(BOOT_CONTROL_HARDWARE_MODULE_ID, hw_module->id) != 0) {
+        ALOGE("Error loading boot_control HAL implementation: %d.", -EINVAL);
+        return nullptr;
+    }
+    module = reinterpret_cast<boot_control_module_t*>(const_cast<hw_module_t*>(hw_module));
+    module->init(module);
+    return new BootControl(module);
+}
+#else
 IBootControl* HIDL_FETCH_IBootControl(const char* /* hal */) {
     int ret = 0;
     boot_control_module_t* module = NULL;
@@ -106,7 +126,7 @@ IBootControl* HIDL_FETCH_IBootControl(const char* /* hal */) {
     module->init(module);
     return new BootControl(module);
 }
-
+#endif
 } // namespace implementation
 }  // namespace V1_0
 }  // namespace boot