Merge 6780759 into merged_master (Bitcoin PR bitcoin/bitcoin#23478)

depends/README.md

@@ -41,7 +41,7 @@ Common `host-platform-triplet`s for cross compilation are:
 - `i686-linux-android` for Android x86 32 bit
 - `x86_64-linux-android` for Android x86 64 bit
 
-The paths are automatically configured and no other options are needed unless targeting [Android](#Android).
+The paths are automatically configured and no other options are needed unless targeting [Android](../doc/build-android.md).
 
 ### Install the required dependencies: Ubuntu & Debian
 
@@ -133,18 +133,6 @@ options will be passed to bitcoin's configure. In this case, `--disable-wallet`.
     download-linux: run 'make download-linux' to fetch all sources needed for linux builds
 
 
-### Android
-
-Before proceeding with an Android build one needs to get the [Android SDK](https://developer.android.com/studio) and use the "SDK Manager" tool to download the NDK and one or more "Platform packages" (these are Android versions and have a corresponding API level).
-In order to build `ANDROID_API_LEVEL` (API level corresponding to the Android version targeted, e.g. Android 9.0 Pie is 28 and its "Platform package" needs to be available) and `ANDROID_TOOLCHAIN_BIN` (path to toolchain binaries depending on the platform the build is being performed on) need to be set.
-
-API levels from 24 to 29 have been tested to work.
-
-If the build includes Qt, environment variables `ANDROID_SDK` and `ANDROID_NDK` need to be set as well but can otherwise be omitted.
-This is an example command for a default build with no disabled dependencies:
-
-    ANDROID_SDK=/home/user/Android/Sdk ANDROID_NDK=/home/user/Android/Sdk/ndk-bundle make HOST=aarch64-linux-android ANDROID_API_LEVEL=28 ANDROID_TOOLCHAIN_BIN=/home/user/Android/Sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin
-
 ### Other documentation
 
 - [description.md](description.md): General description of the depends system

depends/hosts/android.mk

@@ -1,12 +1,11 @@
 ifeq ($(HOST),armv7a-linux-android)
-android_AR=$(ANDROID_TOOLCHAIN_BIN)/arm-linux-androideabi-ar
 android_CXX=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)eabi$(ANDROID_API_LEVEL)-clang++
 android_CC=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)eabi$(ANDROID_API_LEVEL)-clang
-android_RANLIB=$(ANDROID_TOOLCHAIN_BIN)/arm-linux-androideabi-ranlib
 else
-android_AR=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)-ar
 android_CXX=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)$(ANDROID_API_LEVEL)-clang++
 android_CC=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)$(ANDROID_API_LEVEL)-clang
-android_RANLIB=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)-ranlib
 endif
+android_AR=$(ANDROID_TOOLCHAIN_BIN)/llvm-ar
+android_RANLIB=$(ANDROID_TOOLCHAIN_BIN)/llvm-ranlib
+
 android_cmake_system=Android

doc/build-android.md

@@ -3,9 +3,22 @@ ANDROID BUILD NOTES
 
 This guide describes how to build and package the `bitcoin-qt` GUI for Android on Linux and macOS.
 
-## Preparation
 
-You will need to get the Android NDK and build dependencies for Android as described in [depends/README.md](../depends/README.md).
+## Dependencies
+
+Before proceeding with an Android build one needs to get the [Android SDK](https://developer.android.com/studio) and use the "SDK Manager" tool to download the NDK and one or more "Platform packages" (these are Android versions and have a corresponding API level).
+
+The minimum supported Android NDK version is [r21](https://github.com/android/ndk/wiki/Changelog-r21).
+
+In order to build `ANDROID_API_LEVEL` (API level corresponding to the Android version targeted, e.g. Android 9.0 Pie is 28 and its "Platform package" needs to be available) and `ANDROID_TOOLCHAIN_BIN` (path to toolchain binaries depending on the platform the build is being performed on) need to be set.
+
+API levels from 24 to 29 have been tested to work.
+
+If the build includes Qt, environment variables `ANDROID_SDK` and `ANDROID_NDK` need to be set as well but can otherwise be omitted.
+This is an example command for a default build with no disabled dependencies:
+
+    ANDROID_SDK=/home/user/Android/Sdk ANDROID_NDK=/home/user/Android/Sdk/ndk-bundle make HOST=aarch64-linux-android ANDROID_API_LEVEL=28 ANDROID_TOOLCHAIN_BIN=/home/user/Android/Sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin
+
 
 ## Building and packaging