How to fill unused spaces during Keil compilation?

我正在写BootLoader的程序，我想要实现IAP，我目前编译后生成的.bin文件大小为18kb（之后代码多了还会再增加），但是我APPUP区空间为248KB，我的配置为：

Translation (by google translator):

"I'm writing a BootLoader program and I want to implement In-App Access (IAP). The .bin file I'm currently compiling is 18kb in size (and will increase as the code grows), but my app upload space is 248KB. My configuration is..."

我想要实现生成的.bin文件为248kb，不够的地方自动填充，我的生成.bin的指令如下

"I want to generate a .bin file that is 248kb in size, with automatic padding if necessary. My command to generate the .bin file is as follows:"

我的编译器版本为：

"My compiler version is:"

keil5版本为：5.38.0.0

"The Keil 5 version is 5.38.0.0."