first cut at turnon scripts for EasyTimer v2

[fw/altos] / altoslib / AltosHexfile.java

diff --git a/altoslib/AltosHexfile.java b/altoslib/AltosHexfile.java
index 14f660a0bbcb0c4d38f406d31d2029d3fea3c711..718826001755a0dedf1a1b9725b94a30e3fcf7f4 100644 (file)
--- a/altoslib/AltosHexfile.java
+++ b/altoslib/AltosHexfile.java
@@ -287,6 +287,8 @@ public class AltosHexfile {
                return null;
        }
 
+       private static final int look_around[] = { 0, -2, 2, -4, 4 };
+
        private long find_usb_descriptors() {
                AltosHexsym     usb_descriptors = lookup_symbol("ao_usb_descriptors");
                long            a;
@@ -294,24 +296,22 @@ public class AltosHexfile {
                if (usb_descriptors == null)
                        return -1;
 
-               try {
-                       /* The address of this has moved depending on
-                        * padding in the linker script. Look forward
-                        * and backwards two bytes to see if we can find it
-                        */
-                       a = usb_descriptors.address;
-
-                       if (get_u8(a) == 0x12 && get_u8(a+1) == AO_USB_DESC_DEVICE)
-                               return a;
-                       else if (get_u8(a+1) == 0x12 && get_u8(a+3) == AO_USB_DESC_DEVICE)
-                               return a + 2;
-                       else if (get_u8(a-2) == 0x12 && get_u8(a-1) == AO_USB_DESC_DEVICE)
-                               return a - 2;
+               /* The address of this has moved depending on padding
+                * in the linker script and romconfig symbols. Look
+                * forward and backwards two and four bytes to see if
+                * we can find it
+                */
+               a = usb_descriptors.address;
 
-                       return -1;
-               } catch (ArrayIndexOutOfBoundsException ae) {
-                       return -1;
+               for (int look : look_around) {
+                       try {
+                               if (get_u8(a + look) == 0x12 && get_u8(a + look + 1) == AO_USB_DESC_DEVICE)
+                                       return a;
+                       } catch (ArrayIndexOutOfBoundsException ae) {
+                               continue;
+                       }
                }
+               return -1;
        }
 
        public AltosUsbId find_usb_id() {