diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06e0f568..5412a374 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -187,6 +187,8 @@ set(demos
 	demo_zuc
 )
 
+include(CheckSymbolExists)
+
 # when an option has been enabled, `cmake ..` will not refresh the value
 # use `cmake .. -DENABLE_XXX=OFF` to disable the option
 
@@ -254,16 +256,29 @@ endif()
 
 option(ENABLE_INTEL_RDRAND "Enable Intel RDRAND instructions" OFF)
 option(ENABLE_INTEL_RDSEED "Enable Intel RDSEED instructions" OFF)
-if (${CMAKE_SYSTEM_PROCESSOR} MATCHES x86_64)
-	set(ENABLE_INTEL_RDRAND ON)
-endif()
+
 if (ENABLE_INTEL_RDRAND)
-	message(STATUS "ENABLE_INTEL_RDRAND")
-	list(APPEND src src/rdrand.c)
-	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mrdrnd")
+	include(CheckSourceCompiles)
+	set(CMAKE_REQUIRED_FLAGS "-rdrand")
+	check_source_compiles(C
+		"#include <immintrin.h> int main(void) { unsigned long long val; _rdrand64_step(&val); return 0; }"
+		HAVE_INTEL_RDRAND)
+	if (HAVE_INTEL_RDRAND)
+		message(STATUS "ENABLE_INTEL_RDRAND")
+		add_definitions(-DINTEL_RDRAND)
+		list(APPEND src src/rdrand.c)
+		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mrdrnd")
+	endif()
 	if (ENABLE_INTEL_RDSEED)
-		add_definitions(-DINTEL_RDSEED)
-		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mrdseed")
+		set(CMAKE_REQUIRED_FLAGS "-rdseed")
+		check_source_compiles(C
+			"#include <immintrin.h> int main(void) { unsigned long long val; _rdseed64_step(&val); return 0; }"
+			HAVE_INTEL_RDSEED)
+		if (HAVE_INTEL_RDSEED)
+			message(STATUS "ENABLE_INTEL_RDSEED")
+			add_definitions(-DINTEL_RDSEED)
+			set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mrdseed")
+		endif()
 	endif()
 endif()
 
@@ -275,16 +290,20 @@ if (ENABLE_GMT_0105_RNG)
 	list(APPEND tests sm3_rng sm4_cbc_mac sm4_rng)
 endif()
 
+
+check_symbol_exists(getentropy "unistd.h" HAVE_GETENTROPY)
 if (WIN32)
 	list(APPEND src src/rand_win.c src/http_win.c)
 elseif (APPLE)
 	list(APPEND src src/rand_apple.c src/http.c)
-elseif (ANDROID)
-	list(APPEND src src/rand.c src/http.c)
-else()
+elseif (HAVE_GETENTROPY)
 	list(APPEND src src/rand_unix.c src/http.c)
+	 message(STATUS "have getentropy")
+else()
+	list(APPEND src src/rand.c src/http.c)
 endif()
 
+
 option(ENABLE_HTTP_TESTS "Enable HTTP GET/POST related tests" OFF)
 if (ENABLE_HTTP_TESTS)
 	message(STATUS "ENABLE_HTTP_TESTS")
diff --git a/tools/rand.c b/tools/rand.c
index 07af527d..b71610b5 100644
--- a/tools/rand.c
+++ b/tools/rand.c
@@ -17,7 +17,7 @@
 #include <gmssl/rand.h>
 
 
-static const char *options = "[-hex] [-rdrand] -outlen num [-out file]";
+static const char *options = "[-hex] [-rdrand|-rdseed] -outlen num [-out file]";
 
 int rand_main(int argc, char **argv)
 {
@@ -25,6 +25,7 @@ int rand_main(int argc, char **argv)
 	char *prog = argv[0];
 	int hex = 0;
 	int rdrand = 0;
+	int rdseed = 0;
 	int outlen = 0;
 	char *outfile = NULL;
 	FILE *outfp = stdout;
@@ -47,6 +48,8 @@ int rand_main(int argc, char **argv)
 			hex = 1;
 		} else if (!strcmp(*argv, "-rdrand")) {
 			rdrand = 1;
+		} else if (!strcmp(*argv, "-rdseed")) {
+			rdseed = 1;
 		} else if (!strcmp(*argv, "-outlen")) {
 			if (--argc < 1) goto bad;
 			outlen = atoi(*(++argv));
@@ -82,12 +85,23 @@ bad:
 		size_t len = outlen < sizeof(buf) ? outlen : sizeof(buf);
 
 		if (rdrand) {
-/*
+#ifdef INTEL_RDRAND
 			if (rdrand_bytes(buf, len) != 1) {
 				fprintf(stderr, "%s: inner error\n", prog);
 				goto end;
 			}
-*/
+#else
+			fprintf(stderr, "%s: `-rdrand` is not supported on your platform\n", prog);
+#endif
+		} else if (rdseed) {
+#ifdef INTEL_RDSEED
+			if (rdseed_bytes(buf, len) != 1) {
+				fprintf(stderr, "%s: inner error\n", prog);
+				goto end;
+			}
+#else
+			fprintf(stderr, "%s: `-rdseed` is not supported on your platform\n", prog);
+#endif
 		} else {
 			if (rand_bytes(buf, len) != 1) {
 				fprintf(stderr, "%s: inner error\n", prog);