diff --git a/example/boot2/boot2.ld b/example/boot2/boot2.ld
index 27a688a..b1cce04 100644
--- a/example/boot2/boot2.ld
+++ b/example/boot2/boot2.ld
@@ -27,8 +27,12 @@ SECTIONS
         KEEP(*boot2_pre.*(.text.boot2_pre))
         KEEP(*(.text.boot2_pre))
         _boot2_pre_size = . - ADDR(.boot2_pre);
-        ASSERT(_boot2_pre_size <= 252, "Error: .boot2_pre size exceeds 252 bytes!");
-        . += 256 - _boot2_pre_size;
+        ASSERT(_boot2_pre_size <= 240, "Error: .boot2_pre size exceeds 240 bytes!");
+        . += 240 - _boot2_pre_size;
+        LONG(_env_start) /* envionment variables start address */
+        LONG(0)
+        LONG(0)
+        LONG(0) /* MPEG2 of CRC32 */
     } >AUTO AT > FLASH :boot2_pre
 
     .text :
@@ -63,4 +67,8 @@ SECTIONS
         . = ALIGN(4);
         _bss_end = .;
     } >RAM :bss
+
+    _env_start = ADDR(.bss);
+    _env_start = ALIGN(4K);
+    _env_start = _env_start - (ORIGIN(RAM) - ORIGIN(FLASH));
 }
diff --git a/example/boot2/boot2_pre.S b/example/boot2/boot2_pre.S
index f9a6f98..a1cb425 100644
--- a/example/boot2/boot2_pre.S
+++ b/example/boot2/boot2_pre.S
@@ -12,7 +12,5 @@ boot2_pre:
     bl boot2_copy_self
     bl main
     b .
-    .word 0x11223344
-    .word 0xabcdef58
 
 .size  .boot2_pre, .-boot2_pre