diff --git a/app/readme.txt b/app/readme.txt
index 3e243ed4..23f41d72 100644
--- a/app/readme.txt
+++ b/app/readme.txt
@@ -1,4 +1,4 @@
-1¡¢compile options
+1¡¢compile options
 
 (1) COMPILE
     Possible value: gcc
@@ -27,14 +27,14 @@
     Possible value: QIO/QOUT/DIO/DOUT
     Default value: QIO
 
-(4) SPI_SIZE
-    Possible value: 256/512/1024/2048/4096
-    Default value: 512
+(4) SPI_SIZE_MAP
+    Possible value: 0/2/3/4/5/6
+    Default value: 0
 
 For example:
-    make COMPILE=gcc BOOT=new APP=1 SPI_SPEED=40 SPI_MODE=QIO SPI_SIZE=512
+    make COMPILE=gcc BOOT=new APP=1 SPI_SPEED=40 SPI_MODE=QIO SPI_SIZE_MAP=0
 
-2¡¢You can also use gen_misc to make and generate specific bin you needed.
+2¡¢You can also use gen_misc to make and generate specific bin you needed.
     Linux: ./gen_misc.sh
     Windows: gen_misc.bat
-    Follow the tips and steps.
\ No newline at end of file
+    Follow the tips and steps.