Assembly ARM cortex M3汇编程序中任意地址的程序_Assembly_Arm_Cortex M3

Assembly ARM cortex M3汇编程序中任意地址的程序

assembly arm

Assembly ARM cortex M3汇编程序中任意地址的程序,assembly,arm,cortex-m3,Assembly,Arm,Cortex M3,有人知道如何将程序放在ARM汇编程序内存中的任意地址吗？默认情况下，程序的位置从地址0x00000008开始，但它必须位于地址0x200000处。我试图使用DCD 0x200000，但这只会更改寄存器指针，而程序仍保持在旧地址。space0x400命令运行良好，但如果地址太大，则编译需要很长时间。告诉我，也许面对这个 /opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s /

有人知道如何将程序放在ARM汇编程序内存中的任意地址吗？默认情况下，程序的位置从地址0x00000008开始，但它必须位于地址0x200000处。我试图使用

DCD 0x200000

，但这只会更改寄存器指针，而程序仍保持在旧地址。

space0x400

命令运行良好，但如果地址太大，则编译需要很长时间。告诉我，也许面对这个

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

您通常可以通过修改正在使用的链接器脚本，或者通过向GNU ld提供某些命令行选项来实现此结果

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

根据您提供的信息，我假设您的代码当前在两个第一个向量条目表之后启动，即初始SP值和重置值，并且您的向量表位于0x00000000

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

示例1.s应该或多或少像您当前的代码：

        .cpu    cortex-m3
        .thumb    
        .syntax unified
        .global Reset_Handler
        .equ    StackTop, 0x1000
        .word   StackTop         
        .word   Reset_Handler
Reset_Handler:
         b .
        .end


/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example1.o -c example1.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler -Ttext-segment=0x00000000 -Map=example1.map -o example1.elf example1.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d example1.elf

example1.elf:     file format elf32-littlearm

Disassembly of section .text:

00000000 <Reset_Handler-0x8>:
   0:   00001000        .word   0x00001000
   4:   00000008        .word   0x00000008

00000008 <Reset_Handler>:
   8:   e7fe            b.n     8 <Reset_Handler>

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

重置\u处理程序：
b

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as-o示例2.o-c示例2.s
/opt/arm/gcc-arm-8.2-2019.01-x86\u 64-arm-eabi/bin/arm-eabi-ld-g-e重置\u处理程序--节开始=.vectors=0x00000000-Ttext段=0x200000-Map=example2.Map-o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld:警告：“文本段”的地址不是最大页面大小的倍数
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump-d-j.vectors-j.text-d example2.elf
示例2.elf：文件格式elf32 littlearm
节向量的分解：
00000000 :
0:000011000.字0x000011000
4:20002000。单词0x20002000
第节的分解。正文：
20002000 :
20002000:e7fe b.n 20002000
.完

向量表仍然位于正确的内存位置，但代码现在位于0x20002000

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

为了描述为获得相同结果而使用的链接器脚本中所需的确切更改，我需要查看其内容。

您通常可以通过修改正在使用的链接器脚本或向GNU ld提供某些命令行选项来实现此结果

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

根据您提供的信息，我假设您的代码当前在两个第一个向量条目表之后启动，即初始SP值和重置值，并且您的向量表位于0x00000000

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

示例1.s应该或多或少像您当前的代码：

        .cpu    cortex-m3
        .thumb    
        .syntax unified
        .global Reset_Handler
        .equ    StackTop, 0x1000
        .word   StackTop         
        .word   Reset_Handler
Reset_Handler:
         b .
        .end


/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example1.o -c example1.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler -Ttext-segment=0x00000000 -Map=example1.map -o example1.elf example1.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d example1.elf

example1.elf:     file format elf32-littlearm

Disassembly of section .text:

00000000 <Reset_Handler-0x8>:
   0:   00001000        .word   0x00001000
   4:   00000008        .word   0x00000008

00000008 <Reset_Handler>:
   8:   e7fe            b.n     8 <Reset_Handler>

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

重置\u处理程序：
b

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as-o示例2.o-c示例2.s
/opt/arm/gcc-arm-8.2-2019.01-x86\u 64-arm-eabi/bin/arm-eabi-ld-g-e重置\u处理程序--节开始=.vectors=0x00000000-Ttext段=0x200000-Map=example2.Map-o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld:警告：“文本段”的地址不是最大页面大小的倍数
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump-d-j.vectors-j.text-d example2.elf
示例2.elf：文件格式elf32 littlearm
节向量的分解：
00000000 :
0:000011000.字0x000011000
4:20002000。单词0x20002000
第节的分解。正文：
20002000 :
20002000:e7fe b.n 20002000
.完

向量表仍然位于正确的内存位置，但代码现在位于0x20002000

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

为了描述为获得相同结果而使用的链接器脚本中所需的确切更改，我需要查看其内容。

基本上有两种方法可以使用Keil控制代码区域的位置。使用散布文件，或使用“构建选项”对话框中的“目标”选项卡

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

您可以定义一个IROM区域，其中包括您希望代码所在的区域。您还可以使用此对话框生成初始散布文件，然后根据Keil文档修改散布文件

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

但是，您在这里给出的位置位于RAM区域，这有点不寻常（可能效率低下，但有效）。你有没有考虑过如何在重启后初始化你的目标

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

最大的问题是，在复位时，Cortex-M3总是从地址0、4（和8）读取数据（由于预取）。您需要提供初始堆栈指针（或不使用堆栈）和重置向量（使用位0，T位，set）。内存映射可能有硬件存储（特定于设备），但程序员的观点始终是这些获取从地址0开始。

基本上有两种方法可以使用Keil控制代码区域的位置。使用散布文件，或使用“构建选项”对话框中的“目标”选项卡

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

您可以定义一个IROM区域，其中包括您希望代码所在的区域。您还可以使用此对话框生成初始散布文件，然后根据Keil文档修改散布文件

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

但是，您在这里给出的位置位于RAM区域，这有点不寻常（可能效率低下，但有效）。你有没有考虑过如何在重启后初始化你的目标

/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-as -o example2.o -c example2.s
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld -g -e Reset_Handler --section-start=.vectors=0x00000000 -Ttext-segment=0x20002000 -Map=example2.map -o example2.elf example2.o
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-ld: warning: address of `text-segment' isn't multiple of maximum page size
/opt/arm/gcc-arm-8.2-2019.01-x86_64-arm-eabi/bin/arm-eabi-objdump -d -j .vectors -j .text -d example2.elf

example2.elf:     file format elf32-littlearm


Disassembly of section .vectors:

00000000 <.vectors>:
   0:   00001000        .word   0x00001000
   4:   20002000        .word   0x20002000

Disassembly of section .text:

20002000 <Reset_Handler>:
20002000:       e7fe            b.n     20002000 <Reset_Handler>
        .end

最大的问题是，在复位时，Cortex-M3总是从地址0、4（和8）读取数据，因为