added update & uboot functions

resources/scripts/ab_active

@@ -1,4 +1,4 @@
- #!/bin/bash
+#!/bin/bash
 set -e
 
 # get current partition index

resources/scripts/ab_flash

@@ -1,4 +1,4 @@
- #!/bin/bash
+#!/bin/bash
 set -e
 
 image_file=$1

resources/uboot.c

@@ -71,7 +71,7 @@ int main(int argc, char* argv[]) {
         data[1] = 0;
 
         // boot partition
-        data[2] = 2; // A=2, B=3
+        data[2] = 2; // A=1, B=2
     }
 
     // handle commands