Added search functionality using binary search

src/w25qxx.cpp

@@ -44,6 +44,31 @@ namespace sta
         return 1;
     }
 
+    uint32_t W25Qxx::findLastPage(std::function<bool(uint8_t*)> criterion)
+    {
+        uint32_t left   = 0;
+        uint32_t right  = 0xFFFFFFFF & (addrMode_ == AddressMode::_32BIT ? 0xFFFFFFFF : 0x00FFFFFF);
+        uint32_t middle;
+        uint8_t * page = new uint8_t[256];
+
+        while (left < right)
+        {
+            middle = (left + right) / 2 + 1;
+            readData(middle, page, 256);
+
+            if (criterion(page))
+            {
+                left = middle;
+            }
+            else
+            {
+                right = middle-1;
+            }
+        }
+
+        return middle;
+    }
+
     uint8_t W25Qxx::setAddressMode(AddressMode addrMode)
     {
         busWrite(W25QXX_4_BYTE_ADDR_ENABLE);