Arm objcopy后以二进制显示的额外数据。。。它是从哪里来的?

Arm objcopy后以二进制显示的额外数据。。。它是从哪里来的?,arm,embedded,stm32,elf,objcopy,Arm,Embedded,Stm32,Elf,Objcopy,我有一个STM32项目,涉及一个linkerscript,它的设计目的是用“.firmware_header”部分覆盖图像的结尾。其思想是,此标头包含图像的crc,并且在这一点之后不应有任何内容。然而,当我 arm-none-eabi-objcopy firmware.elf -O binary firmware.bin 在最后一节之后存在一些数据,出于某种原因,需要这些数据才能启动映像。如果我将此神秘块归零,图像将无法启动。第一个问题是,从我看到的elf部分来看,在.firmware\u头之

我有一个STM32项目,涉及一个linkerscript,它的设计目的是用“.firmware_header”部分覆盖图像的结尾。其思想是,此标头包含图像的crc,并且在这一点之后不应有任何内容。然而,当我

arm-none-eabi-objcopy firmware.elf -O binary firmware.bin
在最后一节之后存在一些数据,出于某种原因,需要这些数据才能启动映像。如果我将此神秘块归零,图像将无法启动。第一个问题是,从我看到的elf部分来看,在.firmware\u头之后不应该有任何部分,数据来自哪里?第二个问题是,为什么启动时需要这些数据?下面是我的链接器脚本、readelf输出和神秘数据的屏幕截图

ENTRY(Reset_Handler)

MEMORY
{
  FLASH (RX) : ORIGIN = 0x08020000, LENGTH = 896K
  SRAM (RWX) : ORIGIN = 0x20000000, LENGTH = 512K
  BKPSRAM (RW) : ORIGIN = 0x40024000, LENGTH = 4K
}

_estack = 0x20080000;

SECTIONS
{
  .isr_vector :
  {
    . = ALIGN(4);
    _isr_vector = .;
    KEEP(*(.isr_vector))
    . = ALIGN(4);
  } > FLASH

  .firmware_header_vector :
  {
    . = ALIGN(4);
    KEEP(*(.firmware_header_vector))
    . = ALIGN(4);
  } > FLASH

  .text :
  {
    . = ALIGN(4);
    _stext = .;
    *(.Reset_Handler)
    *(.text)
    *(.text*)
    *(.rodata)
    *(.rodata*)
    *(.glue_7)
    *(.glue_7t)
    KEEP(*(.init))
    KEEP(*(.fini))
    . = ALIGN(4);
    _etext = .;

  } > FLASH

  .ARM.extab :
  {
    . = ALIGN(4);
    *(.ARM.extab)
    *(.gnu.linkonce.armextab.*)
    . = ALIGN(4);
  } > FLASH

  .exidx :
  {
    . = ALIGN(4);
    PROVIDE(__exidx_start = .);
    *(.ARM.exidx*)
    . = ALIGN(4);
    PROVIDE(__exidx_end = .);
  } > FLASH

  .preinit_array :
  {
    PROVIDE(__preinit_array_start = .);
    KEEP(*(.preinit_array*))
    PROVIDE(__preinit_array_end = .);
  } > FLASH

  .init_array :
  {
    PROVIDE(__init_array_start = .);
    KEEP(*(SORT(.init_array.*)))
    KEEP(*(.init_array*))
    PROVIDE(__init_array_end = .);
  } > FLASH

  .fini_array :
  {
    PROVIDE(__fini_array_start = .);
    KEEP(*(.fini_array*))
    KEEP(*(SORT(.fini_array.*)))
    PROVIDE(__fini_array_end = .);
  } > FLASH

  .firmware_header :
  {
    . = ALIGN(4);
    KEEP(*(.firmware_header))
    . = ALIGN(4);
  } > FLASH

  . = ALIGN(4);
  _sidata = .;

  .data : AT(_sidata)
  {
    . = ALIGN(4);
    _sdata = .;

    PROVIDE(__data_start__ = _sdata);
    *(.data)
    *(.data*)
    . = ALIGN(4);
    _edata = .;

    PROVIDE(__data_end__ = _edata);
  } > SRAM

  .bss :
  {
    . = ALIGN(4);
    _sbss = .;

    PROVIDE(__bss_start__ = _sbss);
    *(.bss)
    *(.bss*)
    *(COMMON)
    . = ALIGN(4);
    _ebss = .;

    PROVIDE(__bss_end__ = _ebss);
  } > SRAM

  PROVIDE(end = .);

  .heap (NOLOAD) :
  {
    . = ALIGN(4);
    PROVIDE(__heap_start__ = .);
    KEEP(*(.heap))
    . = ALIGN(4);
    PROVIDE(__heap_end__ = .);
  } > SRAM

  .reserved_for_stack (NOLOAD) :
  {
    . = ALIGN(4);
    PROVIDE(__reserved_for_stack_start__ = .);
    KEEP(*(.reserved_for_stack))
    . = ALIGN(4);
    PROVIDE(__reserved_for_stack_end__ = .);
  } > SRAM

  .battery_backed_sram (NOLOAD) :
  {
    . = ALIGN(4);
    KEEP(*(.battery_backed_sram))
    . = ALIGN(4);
  } > BKPSRAM

  /DISCARD/ :
  {
    *(.ARM.attributes)
  }
}
arm none eabi readelf-a./fw.elf:

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:               0x8027c11
  Start of program headers:          52 (bytes into file)
  Start of section headers:          339928 (bytes into file)
  Flags:                             0x5000400, Version5 EABI, hard-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         3
  Size of section headers:           40 (bytes)
  Number of section headers:         25
  Section header string table index: 24

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] .isr_vector       PROGBITS        08020000 010000 0001f8 00  WA  0   0  4
  [ 2] .firmware_header_ PROGBITS        080201f8 0101f8 000004 00  WA  0   0  4
  [ 3] .text             PROGBITS        08020200 010200 021b44 00  AX  0   0 64
  [ 4] .ARM.extab        PROGBITS        08041d44 043a68 000000 00   W  0   0  1
  [ 5] .exidx            ARM_EXIDX       08041d44 031d44 000008 00  AL  3   0  4
  [ 6] .init_array       INIT_ARRAY      08041d4c 031d4c 000008 04  WA  0   0  4
  [ 7] .fini_array       FINI_ARRAY      08041d54 031d54 000004 04  WA  0   0  4
  [ 8] .firmware_header  PROGBITS        08041d58 031d58 000008 00  WA  0   0  4
  [ 9] .data             PROGBITS        20000000 040000 0009c8 00  WA  0   0  8
  [10] .RxDecripSection  PROGBITS        200009c8 0409c8 000080 00  WA  0   0  4
  [11] .RxarraySection   PROGBITS        20000a48 040a48 0017d0 00  WA  0   0  4
  [12] .TxDescripSection PROGBITS        20002218 042218 000080 00  WA  0   0  4
  [13] .TxarraySection   PROGBITS        20002298 042298 0017d0 00  WA  0   0  4
  [14] .bss              NOBITS          20003a68 043a68 045da4 00  WA  0   0  4
  [15] .heap             PROGBITS        2004980c 043a68 000000 00   W  0   0  1
  [16] .reserved_for_sta PROGBITS        2004980c 043a68 000000 00   W  0   0  1
  [17] .battery_backed_s NOBITS          40024000 044000 00000c 00  WA  0   0  4
  [18] .comment          PROGBITS        00000000 043a68 000075 01  MS  0   0  1
  [19] .debug_frame      PROGBITS        00000000 043ae0 00144c 00      0   0  4
  [20] .stab             PROGBITS        00000000 044f2c 000084 0c     21   0  4
  [21] .stabstr          STRTAB          00000000 044fb0 000117 00      0   0  1
  [22] .symtab           SYMTAB          00000000 0450c8 009b30 10     23 1790  4
  [23] .strtab           STRTAB          00000000 04ebf8 0042bb 00      0   0  1
  [24] .shstrtab         STRTAB          00000000 052eb3 000122 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 0x08020000 0x08020000 0x21d60 0x21d60 RWE 0x10000
  LOAD           0x040000 0x20000000 0x08041d60 0x03a68 0x4980c RW  0x10000
  LOAD           0x044000 0x40024000 0x40024000 0x00000 0x0000c RW  0x10000

事实证明,这是.data部分定义的一个问题。它将在.firmware\u头之后加载。有趣的是,在readefl等输出中,这一点并没有变得更清楚。解决了

我不明白是什么让你惊讶?section.data在链接器脚本中的section.firmware\u头之后,因此它是有意义的。您可能被以下事实弄糊涂了:.data部分有不同的加载和执行地址,readelf显示执行地址。您还可以查看.map文件,在该文件中可以看到两个地址