我尝试在STM32设备上使用c++，用gcc编译。设备加载代码并开始执行，但在任何成员变量写入时出现硬错误。
我可以看到GDB的成员变量存储在内存的开始（具体来说是0x7），当然STM32在第一次写入该位置时会出现硬错误。
我可以看到BSS部分不会生成，除非我在main中声明一个变量（在最终的elf文件中使用readelf）。
成员变量不应该放在bss中吗？
我正在编译和链接-nostdlib -mcpu=cortex-m0plus -fno-exceptions -O0 -g。
链接器脚本为：

ENTRY(start_of_memory);

MEMORY {

    rom (rx)  : ORIGIN = 0x08000000, LENGTH = 16K
    ram (xrw) : ORIGIN = 0x20000000, LENGTH = 2K

}

SECTIONS {

    .text : {
        *(.text)
    } > rom

    .data : { 
        *(.data)
        *(.data.*)
    } > ram

    .bss : { 
        *(.bss)
        *(.bss.*)
        *(COMMON)
    } > ram

}

readelf的输出（没有变量声明，只有对象用法）：

ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x8000000
  Start of program headers:          52 (bytes into file)
  Start of section headers:          76536 (bytes into file)
  Flags:                             0x5000200, Version5 EABI, soft-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         1
  Size of section headers:           40 (bytes)
  Number of section headers:         14
  Section header string table index: 13

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] .text             PROGBITS        08000000 010000 0005a8 00  AX  0   0  4
  [ 2] .rodata           PROGBITS        080005a8 0105a8 00005c 00   A  0   0  4
  [ 3] .ARM.attributes   ARM_ATTRIBUTES  00000000 010604 00002d 00      0   0  1
  [ 4] .comment          PROGBITS        00000000 010631 000049 01  MS  0   0  1
  [ 5] .debug_info       PROGBITS        00000000 01067a 000a93 00      0   0  1
  [ 6] .debug_abbrev     PROGBITS        00000000 01110d 0003b8 00      0   0  1
  [ 7] .debug_aranges    PROGBITS        00000000 0114c5 000060 00      0   0  1
  [ 8] .debug_line       PROGBITS        00000000 011525 000580 00      0   0  1
  [ 9] .debug_str        PROGBITS        00000000 011aa5 000416 01  MS  0   0  1
  [10] .debug_frame      PROGBITS        00000000 011ebc 000228 00      0   0  4
  [11] .symtab           SYMTAB          00000000 0120e4 000640 10     12  86  4
  [12] .strtab           STRTAB          00000000 012724 000344 00      0   0  1
  [13] .shstrtab         STRTAB          00000000 012a68 00008f 00      0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
  L (link order), O (extra OS processing required), G (group), T (TLS),
  C (compressed), x (unknown), o (OS specific), E (exclude),
  y (purecode), p (processor specific)

There are no section groups in this file.

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x010000 0x08000000 0x08000000 0x00604 0x00604 R E 0x10000

 Section to Segment mapping:
  Segment Sections...
   00     .text .rodata 

There is no dynamic section in this file.

There are no relocations in this file.

There are no unwind sections in this file.

Symbol table '.symtab' contains 100 entries:

main（init平台可能不使用任何变量）：

int main(void) {

    init_platform(SPEED_4_MHz);

    gpio testpin(GPIO_A, 5);
    testpin.dir(MODE_OUTPUT);

    while (1) {

        testpin.high();
        wait();
        testpin.low();
        wait();
    }

    return 0;
    
}

• • 更新#1：**

向量表位于内存开头，sp和msp初始化成功。

(gdb) p/x *0x00000000
$2 = 0x20000700
(gdb) p/x *0x00000004
$3 = 0x80000f1
(gdb) info registers
sp             0x20000700          0x20000700
lr             0xffffffff          -1
pc             0x80000f6           0x80000f6 <main()+6>
xPSR           0xf1000000          -251658240
msp            0x20000700          0x20000700
psp            0xfffffffc          0xfffffffc

在GPIO类的构造函数上放置断点，我可以看到变量位于0x00000XXX

Breakpoint 2, gpio::gpio (this=0x7, port=0 '\000', pin=5 '\005') at gpio.cpp:25
25              mypin = pin;
(gdb) p/x &mypin
$6 = 0xb

我试图使mypin成为一个公共成员变量（是私有的），没有做任何改变。
开始认为C++* 需要 * 动态分配。