pic32 8字节上的静态变量

发布于 2025-01-25 18:44:42 字数 980 浏览 3 评论 0原文

由于某种原因，当我将这两个变量提供“使用”属性时，编译器使它们长8个字节。没有它，编译器将它们优化，因为我不使用它们（尚未使用）。有人知道为什么这是吗？并且有任何已知的解决方法吗？

__attribute__ ((used,section(".booter_version"))) static uint32_t BooterVersion = 2;
__attribute__ ((used,section(".hardware_version"))) static uint32_t HardwareVersion = 3;

包含这些部分的LinkerScript部分：

 /* booter version number is placed at the second last 4 bytes of program mem for the booter*/
 .BooterVersion _BOOTER_VERSION_ADDRESS :
 {
    KEEP (*(.booter_version))
  } >kseg0_program_mem
 /* hardware version number is placed at the end of program mem for the booter */
 .HardwareVersion _HARDWARE_VERSION_ADDRESS :
 {
   KEEP (*(.hardware_version))
 } >kseg0_program_mem

编译后的内存图中的图像（在程序MEM中，您会看到最后两行）：

原文

For some reason, when I give these two variables the "used" attribute, the compiler makes them 8 bytes long. Without it, the compiler optimizes them away as I don't use them (yet). Anyone knows why this is? And are any workarounds for this known?

__attribute__ ((used,section(".booter_version"))) static uint32_t BooterVersion = 2;
__attribute__ ((used,section(".hardware_version"))) static uint32_t HardwareVersion = 3;

Linkerscript part with these sections:

 /* booter version number is placed at the second last 4 bytes of program mem for the booter*/
 .BooterVersion _BOOTER_VERSION_ADDRESS :
 {
    KEEP (*(.booter_version))
  } >kseg0_program_mem
 /* hardware version number is placed at the end of program mem for the booter */
 .HardwareVersion _HARDWARE_VERSION_ADDRESS :
 {
   KEEP (*(.hardware_version))
 } >kseg0_program_mem

Image from the memory map after compiling (in program mem, you see the last two lines for these):