Question

我的代码在这里：

(gdb) s
main () at main.c:74
 74   __CRC_CLK_ENABLE();
(gdb) s
77    Example_Status = 3;
(gdb) p Example_status
No symbol "Example_status" in current context.
(gdb) p Example_Status
$1 = 139640994
(gdb) n
74    __CRC_CLK_ENABLE();
(gdb) n
77    Example_Status = 3;
(gdb) n
183   Example_Status = ExampleECCKeyGenSignVerif();
(gdb) p Example_Status
$2 = 139640994

我使用stlink-texane在我的stm32上的gdb如下：

arm-none-eabi-objdump --syms main.o | grep Example_Status 
00000000 l    d  .bss.Example_Status    00000000 .bss.Example_Status
00000000 g     O .bss.Example_Status    00000004 Example_Status

我想知道为什么Example_Status结果不是= 3？

并且变量的存储是

/* Entry Point */
ENTRY(Reset_Handler)

/* Highest address of the user mode stack */
_estack = 0x20010000;    /* end of RAM */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x000;;      /* required amount of heap  */
_Min_Stack_Size = 0x000;; /* required amount of stack */

/* Specify the memory areas */
MEMORY
{
FLASH (rx)      : ORIGIN = 0x8000000, LENGTH = 128K
RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = 64K
}

/* Define output sections */
SECTIONS
{
  /* The startup code goes first into FLASH */
  .isr_vector :
  {
    . = ALIGN(4);
    KEEP(*(.isr_vector)) /* Startup code */
    . = ALIGN(4);
  } >FLASH

  /* The program code and other data goes into FLASH */
  .text :
  {
    . = ALIGN(4);
    *(.text)           /* .text sections (code) */
    *(.text*)          /* .text* sections (code) */
    *(.glue_7)         /* glue arm to thumb code */
    *(.glue_7t)        /* glue thumb to arm code */
    *(.eh_frame)

    KEEP (*(.init))
    KEEP (*(.fini))

        . = ALIGN(4);
    _etext = .;        /* define a global symbols at end of code */
  } >FLASH

  /* Constant data goes into FLASH */
  .rodata :
  {
    . = ALIGN(4);
    *(.rodata)         /* .rodata sections (constants, strings, etc.) */
    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
    . = ALIGN(4);
  } >FLASH

  .ARM.extab   : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
  .ARM : {
    __exidx_start = .;
    *(.ARM.exidx*)
    __exidx_end = .;
  } >FLASH

  .preinit_array     :
  {
    PROVIDE_HIDDEN (__preinit_array_start = .);
    KEEP (*(.preinit_array*))
    PROVIDE_HIDDEN (__preinit_array_end = .);
  } >FLASH
  .init_array :
  {
    PROVIDE_HIDDEN (__init_array_start = .);
    KEEP (*(SORT(.init_array.*)))
    KEEP (*(.init_array*))
    PROVIDE_HIDDEN (__init_array_end = .);
  } >FLASH
  .fini_array :
  {
    PROVIDE_HIDDEN (__fini_array_start = .);
    KEEP (*(SORT(.fini_array.*)))
    KEEP (*(.fini_array*))
    PROVIDE_HIDDEN (__fini_array_end = .);
  } >FLASH

  /* used by the startup to initialize data */
  _sidata = LOADADDR(.data);

  /* Initialized data sections goes into RAM, load LMA copy after code */
  .data : 
  {
    . = ALIGN(4);
    _sdata = .;        /* create a global symbol at data start */
    *(.data)           /* .data sections */
    *(.data*)          /* .data* sections */

    . = ALIGN(4);
    _edata = .;        /* define a global symbol at data end */
  } >RAM AT> FLASH


  /* Uninitialized data section */
  . = ALIGN(4);
  .bss :
  {
    /* This is used by the startup in order to initialize the .bss secion */
    _sbss = .;         /* define a global symbol at bss start */
    __bss_start__ = _sbss;
    *(.bss)
    *(.bss*)
    *(COMMON)

    . = ALIGN(4);
    _ebss = .;         /* define a global symbol at bss end */
    __bss_end__ = _ebss;
  } >RAM

  /* User_heap_stack section, used to check that there is enough RAM left */
  ._user_heap_stack :
  {
    . = ALIGN(8);
    PROVIDE ( end = . );
    PROVIDE ( _end = . );
    . = . + _Min_Heap_Size;
    . = . + _Min_Stack_Size;
    . = ALIGN(8);
  } >RAM



  /* Remove information from the standard libraries */
  /DISCARD/ :
  {
    libc.a ( * )
    libm.a ( * )
    libgcc.a ( * )
  }

  .ARM.attributes 0 : { *(.ARM.attributes) }
}

我的链接器文件在这里：

75    Example_Status = 1;
0x080002ac <+24>:   and.w   r3, r3, #33554432   ; 0x2000000
0x080002b0 <+28>:   cmp r3, #0

---Type <return> to continue, or q <return> to quit---
76    Example_Status = 2;
0x080002b2 <+30>:   beq.n   0x80002a8 <main+20>
0x080002b4 <+32>:   ldr r3, [pc, #60]   ; (0x80002f4 <main+96>)
0x080002b6 <+34>:   movw    r2, #1795   ; 0x703

77    Example_Status = 3;
0x080002b8 <+36>:   strb    r3, [r0, #8]
0x080002ba <+38>:   str r2, [r3, #0]
0x080002bc <+40>:   ldr r2, [pc, #44]   ; (0x80002ec <main+88>)

//
(gdb) n
75    Example_Status = 1;
(gdb) n
76    Example_Status = 2;
(gdb) p Example_Status
$1 = 140166176
(gdb) s

这是我的第一个linux项目，如果有人可以提供帮助，我会说实话感谢

编辑添加“disassemble / m”

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Answer 1

编译时，如果需要可靠的调试，请不要使用高于0的优化级别进行编译：

gcc -O0 mycode.c -o mycode.o -c

为什么我的vaiable不遵循gdb stm32项目中的代码

1 个答案: