STM32堆栈

1.堆和栈大小

?定义大小在startup_stm32f2xx.s

Stack_Size????? EQU???? 0x00000400

??????????????? AREA??? STACK,NOINIT,READWRITE,ALIGN=3
Stack_Mem?????? SPACE?? Stack_Size
__initial_sp

; <h> Heap Configuration
;?? <o>? Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>

Heap_Size?????? EQU???? 0x00000200

??????????????? AREA??? HEAP,ALIGN=3
__heap_base

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2.堆和栈位置

通过MAP文件可知

?HEAP???????????????????????????????????? 0x200106f8?? Section????? 512? startup_stm32f2xx.o(HEAP)
?STACK??????????????????????????????????? 0x200108f8?? Section???? 1024? startup_stm32f2xx.o(STACK)

?__heap_base????????????????????????????? 0x200106f8?? Data?????????? 0? startup_stm32f2xx.o(HEAP)
?__heap_limit???????????????????????????? 0x200108f8?? Data?????????? 0? startup_stm32f2xx.o(HEAP)
?__initial_sp???????????????????????????? 0x20010cf8?? Data?????????? 0? startup_stm32f2xx.o(STACK)

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显然?Cortex-m3资料可知：__initial_sp是堆栈指针，它就是FLASH的0x8000000地址前面4个字节（它根据堆栈大小，由编译器自动生成）

显然堆和栈是相邻的。

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3.堆和栈空间分配

栈：向低地址扩展

堆：向高地址扩展

显然如果依次定义变量

先定义的栈变量的内存地址比后定义的栈变量的内存地址要大

先定义的堆变量的内存地址比后定义的堆变量的内存地址要小?

4.堆和栈变量

栈：临时变量，退出该作用域就会自动释放

堆：malloc变量，通过free函数释放

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另外：堆栈溢出，编译不会提示，需要注意