change stmflash header file
add file introduction
add usart2.h header file
not important
add SerialKeyPress() function
change function description
change function description
delete original STM description
delete original STM description
define IAP_Port
change function description
add function iput parameter, appaddr
add function iput parameter, appaddr
change comment
delete usart2.h include
delete unused function
delete ymodem transmit function and subfunctions
change introduction
NA
delete ymodem transmit function global declaration