first sample

02_day/jni/Android.mk

@@ -0,0 +1,8 @@
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+LOCAL_CFLAGS    := -fPIE
+LOCAL_LDFLAGS   := -fPIE -pie
+LOCAL_MODULE    := myapp
+LOCAL_SRC_FILES := rdwr_app.c
+include $(BUILD_EXECUTABLE)
+

02_day/jni/myapp.c

@@ -0,0 +1,10 @@
+#include <fcntl.h>
+int main()
+{
+	int fd;
+	fd = open( "/sys/devices/virtual/misc/mydev/uevent", O_WRONLY );
+	write( fd, "add\n", 4 );
+	close(fd);
+	return 0;
+}
+

02_day/jni/rdwr_app.c

@@ -0,0 +1,57 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+int main()
+{
+	int fd, ret;
+	char buff[10];
+	fd = open( "/dev/mydev", O_RDONLY );
+	ret = read( fd, buff, sizeof buff );
+	buff[ret] = 0;
+	printf( "buff[%s], ret=%d\n", buff, ret );
+	close(fd);
+	return 0;
+}
+/*
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+int main()
+{
+	int fd, ret;
+	int temp;
+	fd = open( "/dev/mydev", O_RDONLY );
+	ret = read( fd, &temp, sizeof temp );
+	printf( "temp=%d, ret=%d\n", temp, ret );
+	close(fd);
+	return 0;
+}
+*/
+
+/*
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+int main()
+{
+	int fd, ret;
+	char buff[] = "LED_ON";
+	fd = open( "/dev/mydev", O_WRONLY );
+	ret = write( fd, buff, strlen(buff) );
+	printf( "ret=%d\n", ret );
+	close(fd);
+	return 0;
+}
+*/
+/*
+#include <fcntl.h>
+int main()
+{
+	int fd;
+	int flag=128;
+	fd = open( "/dev/mydev", O_WRONLY );
+	write( fd, &flag, sizeof flag );
+	close(fd);
+	return 0;
+}
+*/