Update and rename readme.md to README.md

bsp/stm32f40x/README.md

+## board info:
+
+    STM32F4 discovery
+    http://www.st.com/internet/evalboard/product/252419.jsp
+
+## note:
+
+in drivers/stm32f4xx_conf.h
+
+```c
+    /* Redefine the HSE value; it's equal to 8 MHz on the STM32F4-DISCOVERY Kit */
+    efine HSE_VALUE    ((uint32_t)8000000)
+```
+ 
+ **================= IAR WARNING =================**
+ 
+After use `scons --target=iar -s` command to product IAR project, you have to add iar link file manually.
+
+IAR IDE steps:
+1. Project-->Options-->Linker
+2. Config-->Linker Configuration file
+3. select `Override Default`, then select `bsp/stm32f40x/stm32f40x_flash.icf`
+4. rebuild project
+
+**TODO**
+
+auto add *.icf by scons script

bsp/stm32f40x/readme.md

-board info:
-STM32F4 discovery
-http://www.st.com/internet/evalboard/product/252419.jsp
-
-note:
-in drivers/stm32f4xx_conf.h
- /* Redefine the HSE value; it's equal to 8 MHz on the STM32F4-DISCOVERY Kit */
- #define HSE_VALUE    ((uint32_t)8000000)
- 
- 
- 
- **================= IAR WARNING =================**
- 
- after use `scons --target=iar -s` cmd to product IAR project, you have to add iar link file by hand
- 
- IAR steps:
- 1. Project-->Options-->Linker
- 2. Config-->Linker Configuration file
- 3. select `Override Default`, then select `bsp/stm32f40x/stm32f40x_flash.icf`
- 4. rebuild project
- 
- 
- **TODO**
- auto add *.icf by scons script
-