android: Set minimum to API level 21

[skip ci]

README.md

@@ -194,9 +194,9 @@ These commands show how to compile wheels for the supported Android ABIs:
 ```bash
 export ANDROID_SDK_ROOT=/home/rdb/local/android
 python3.8 makepanda/makepanda.py --everything --outputdir built-droid-arm64 --arch arm64 --target android-21 --threads 6 --wheel
-python3.8 makepanda/makepanda.py --everything --outputdir built-droid-armv7a --arch armv7a --target android-19 --threads 6 --wheel
+python3.8 makepanda/makepanda.py --everything --outputdir built-droid-armv7a --arch arm --target android-21 --threads 6 --wheel
 python3.8 makepanda/makepanda.py --everything --outputdir built-droid-x86_64 --arch x86_64 --target android-21 --threads 6 --wheel
-python3.8 makepanda/makepanda.py --everything --outputdir built-droid-x86 --arch x86 --target android-19 --threads 6 --wheel
+python3.8 makepanda/makepanda.py --everything --outputdir built-droid-x86 --arch x86 --target android-21 --threads 6 --wheel
 ```
 
 It is now possible to use the generated wheels with `build_apps`, as explained

makepanda/makepanda.py

@@ -485,6 +485,8 @@ elif not CrossCompiling():
 else:
     if target_arch == 'amd64':
         target_arch = 'x86_64'
+    if target_arch == 'arm' and target == 'android':
+        target_arch = 'armv7a'
     PLATFORM = '{0}-{1}'.format(target, target_arch)
 
 
@@ -1371,10 +1373,10 @@ def CompileCxx(obj,src,opts):
                 cmd += ' -gcc-toolchain ' + SDK["ANDROID_GCC_TOOLCHAIN"].replace('\\', '/')
             cmd += ' -ffunction-sections -funwind-tables'
             cmd += ' -target ' + SDK["ANDROID_TRIPLE"]
-            if arch == 'armv7a':
+            if arch in ('armv7a', 'arm'):
                 cmd += ' -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16'
-            elif arch == 'arm':
-                cmd += ' -march=armv5te -mtune=xscale -msoft-float'
+            #elif arch == 'arm':
+            #    cmd += ' -march=armv5te -mtune=xscale -msoft-float'
             elif arch == 'mips':
                 cmd += ' -mips32'
             elif arch == 'mips64':
@@ -1897,7 +1899,7 @@ def CompileLink(dll, obj, opts):
                 cmd += ' -gcc-toolchain ' + SDK["ANDROID_GCC_TOOLCHAIN"].replace('\\', '/')
             cmd += " -Wl,-z,noexecstack -Wl,-z,relro -Wl,-z,now"
             cmd += ' -target ' + SDK["ANDROID_TRIPLE"]
-            if arch == 'armv7a':
+            if arch in ('armv7a', 'arm'):
                 cmd += " -march=armv7-a -Wl,--fix-cortex-a8"
             elif arch == 'mips':
                 cmd += ' -mips32'

makepanda/makepandacore.py

@@ -357,11 +357,11 @@ def SetTarget(target, arch=None):
 
     elif target == 'android' or target.startswith('android-'):
         if arch is None:
-            # If compiling on Android, default to same architecture.  Otherwise, arm.
+            # If compiling on Android, default to same architecture.
             if host == 'android':
                 arch = host_arch
             else:
-                arch = 'armv7a'
+                exit('Specify an Android architecture using --arch')
 
         if arch == 'aarch64':
             arch = 'arm64'
@@ -371,12 +371,9 @@ def SetTarget(target, arch=None):
         target, _, api = target.partition('-')
         if api:
             ANDROID_API = int(api)
-        elif arch in ('mips64', 'arm64', 'x86_64'):
-            # 64-bit platforms were introduced in Android 21.
-            ANDROID_API = 21
         else:
             # Default to the lowest API level still supported by Google.
-            ANDROID_API = 19
+            ANDROID_API = 21
 
         # Determine the prefix for our gcc tools, eg. arm-linux-androideabi-gcc
         global ANDROID_ABI, ANDROID_TRIPLE
@@ -1422,6 +1419,9 @@ def GetThirdpartyDir():
     elif (target == 'android'):
         THIRDPARTYDIR = base + "/android-libs-%s/" % (target_arch)
 
+        if target_arch == 'armv7a' and not os.path.isdir(THIRDPARTYDIR):
+            THIRDPARTYDIR = base + "/android-libs-arm/"
+
     elif (target == 'emscripten'):
         THIRDPARTYDIR = base + "/emscripten-libs/"