keil编译后显示的Program size含义

男娘i 2022-09-07 09:56 130阅读 0赞

## 示例 ##

使用keil编译完成后, 程序会弹出如下类似信息, 可能有些人不关注此类信息, 其实某些时候还是挺有帮助的, 比如裁剪程序尺寸, 使其大小能装进目标机器运行时;

Program Size: Code=33112 RO-data=1108 RW-data=1236 ZI-data=89452  
    FromELF: creating hex file...

## 解释 ##

*  `Code`表示代码占用空间;
 *  `RO`=read-only;
 *  `RW`=read-write;
 *  `ZI`=zero-initialized;

以LPC1768的arm独立运行固件的地址分配为例, 图示如下:

+-----------+ 0x1000 8000 \
    |  Unused   |             |
    +-----------+             |
    |  ZI data  | <--(clear)  | RAM
    +-----------+             |
    |  RW data  | <--(copy)---|---+
    +-----------+ 0x1000 0000 /   |
                                  |
                                  |
    +-----------+ 0x0008 0000 \   |
    |  Unused   |             |   |
    +-----------+             |   |
    |  RW init  |-------------|---+
    +-----------+             |
    |  RO data  |             | ROM (Flash)
    +-----------+             |
    | User code |             |
    +-----------+             |
    | Boot code |             |
    +-----------+             |
    |  Vectors  |             |
    +-----------+ 0x0000 0000 /

因此:

*  ROM (flash) space = code + RO-data + RW-data;
 *  RAM = RW-data + ZI-data;

## 参考文章 ##

1.  [ROM and RAM in ARM][] 文章基本来源于此问题高票答案;
2.  [Keil/MDK 小知识点：Program size: Code, RO-data , RW-data, ZI-data 解释（什么意思）][Keil_MDK _Program size_ Code_ RO-data _ RW-data_ ZI-data] ;
3.  [ARM Program Size - ZI data?][ARM Program Size - ZI data] arm社区的问答帖子内容和stackoverflow的内容差不多, 但不详细;

[ROM and RAM in ARM]: https://stackoverflow.com/questions/5430284/rom-and-ram-in-arm
[Keil_MDK _Program size_ Code_ RO-data _ RW-data_ ZI-data]: https://blog.csdn.net/yuleicqut/article/details/50933441?utm_term=programsize&utm_medium=distribute.pc_aggpage_search_result.none-task-blog-2~all~sobaiduweb~default-0-50933441&spm=3001.4430
[ARM Program Size - ZI data]: https://community.arm.com/developer/tools-software/tools/f/keil-forum/20991/arm-program-size---zi-data