Add tool to dump /proc/cpuinfo under AArch32 on AArch64 systems

CMakeLists.txt

@@ -773,6 +773,10 @@ IF(CPUINFO_SUPPORTED_PLATFORM AND CPUINFO_BUILD_TOOLS)
     CPUINFO_TARGET_ENABLE_C99(auxv-dump)
     CPUINFO_TARGET_RUNTIME_LIBRARY(auxv-dump)
     TARGET_LINK_LIBRARIES(auxv-dump PRIVATE ${CMAKE_DL_LIBS})
+
+    ADD_EXECUTABLE(cpuinfo-dump tools/cpuinfo-dump.c)
+    CPUINFO_TARGET_ENABLE_C99(cpuinfo-dump)
+    CPUINFO_TARGET_RUNTIME_LIBRARY(cpuinfo-dump)
   ENDIF()
 
   IF(CMAKE_SYSTEM_PROCESSOR MATCHES "^(i686|AMD64|x86_64)$")

jni/Android.mk

@@ -154,6 +154,12 @@ LOCAL_SRC_FILES := $(LOCAL_PATH)/tools/auxv-dump.c
 LOCAL_CFLAGS := -std=gnu99
 include $(BUILD_EXECUTABLE)
 
+include $(CLEAR_VARS)
+LOCAL_MODULE := cpuinfo-dump
+LOCAL_SRC_FILES := $(LOCAL_PATH)/tools/cpuinfo-dump.c
+LOCAL_CFLAGS := -std=gnu99
+include $(BUILD_EXECUTABLE)
+
 endif # armeabi, armeabi-v7a, or arm64-v8a
 
 ifeq ($(TARGET_ARCH_ABI),$(filter $(TARGET_ARCH_ABI),x86 x86_64))

tools/cpuinfo-dump.c

@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+
+#define BUFFER_SIZE 4096
+char buffer[BUFFER_SIZE];
+
+#define CPUINFO_PATH "/proc/cpuinfo"
+
+int main(int argc, char** argv) {
+	int file = open(CPUINFO_PATH, O_RDONLY);
+	if (file == -1) {
+		fprintf(stderr, "Error: failed to open %s: %s\n", CPUINFO_PATH, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	/* Only used for error reporting */
+	size_t position = 0;
+	char* data_start = buffer;
+	ssize_t bytes_read;
+	do {
+		bytes_read = read(file, buffer, BUFFER_SIZE);
+		if (bytes_read < 0) {
+			fprintf(stderr, "Error: failed to read file %s at position %zu: %s\n",
+				CPUINFO_PATH, position, strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+
+		position += (size_t) bytes_read;
+		if (bytes_read > 0) {
+			fwrite(buffer, 1, (size_t) bytes_read, stdout);
+		}
+	} while (bytes_read != 0);
+
+	if (close(file) != 0) {
+		fprintf(stderr, "Error: failed to close %s: %s\n", CPUINFO_PATH, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+	return EXIT_SUCCESS;
+}