c - 用于引导加载程序设置的链接器文件 vector 表

Question

我目前正在尝试使用使用 MCUXPresso 创建的引导加载程序应用程序，它要求我的应用程序起始地址位于 0x80000。根据以下文档:

但是，我生成的 .bin 是使用 Kinetis Design Studio(MCUXpresso 的早期版本)创建的，并且没有像在 MCUXPresso 中那样以如此简单的方式修改 vector 表的选项。我一直在尝试手动修改链接器文件，执行以下操作:

ENTRY(Reset_Handler)

    /* Original Memory Map */
MEMORY
{
  m_interrupts          (RX)  : ORIGIN = 0x00000000, LENGTH = 0x00000400
  m_flash_config        (RX)  : ORIGIN = 0x00000400, LENGTH = 0x00000010
  m_text                (RX)  : ORIGIN = 0x00000410, LENGTH = 0x001FFBF0
  m_data                (RW)  : ORIGIN = 0x1FFF0000, LENGTH = 0x00030000
  m_data_2              (RW)  : ORIGIN = 0x20000000, LENGTH = 0x00030000
}

/* Modified Memory Map */

MEMORY
{
  m_interrupts          (RX)  : ORIGIN = 0x00080000, LENGTH = 0x00000400
  m_flash_config        (RX)  : ORIGIN = 0x00080400, LENGTH = 0x00000010
  m_text                (RX)  : ORIGIN = 0x00080410, LENGTH = 0x001FFBF0
  m_data                (RW)  : ORIGIN = 0x1FFF0000, LENGTH = 0x00030000
  m_data_2              (RW)  : ORIGIN = 0x20000000, LENGTH = 0x00030000
}

/* rest of linker file */
/* Define output sections */
SECTIONS
{
  /* The startup code goes first into internal flash */
  .interrupts :
  {
    __VECTOR_TABLE = .;
    . = ALIGN(4);
    KEEP(*(.isr_vector))     /* Startup code */
    . = ALIGN(4);
  } > m_interrupts

  .flash_config :
  {
    . = ALIGN(4);
    KEEP(*(.FlashConfig))    /* Flash Configuration Field (FCF) */
    . = ALIGN(4);
  } > m_flash_config

  /* The program code and other data goes into internal flash */
  .text :
  {
    . = ALIGN(4);
    *(.text)                 /* .text sections (code) */
    *(.text*)                /* .text* sections (code) */
    *(.rodata)               /* .rodata sections (constants, strings, etc.) */
    *(.rodata*)              /* .rodata* sections (constants, strings, etc.) */
    *(.glue_7)               /* glue arm to thumb code */
    *(.glue_7t)              /* glue thumb to arm code */
    *(.eh_frame)
    KEEP (*(.init))
    KEEP (*(.fini))
    . = ALIGN(4);
  } > m_text

  .ARM.extab :
  {
    *(.ARM.extab* .gnu.linkonce.armextab.*)
  } > m_text

  .ARM :
  {
    __exidx_start = .;
    *(.ARM.exidx*)
    __exidx_end = .;
  } > m_text

 .ctors :
  {
    __CTOR_LIST__ = .;
    /* gcc uses crtbegin.o to find the start of
       the constructors, so we make sure it is
       first.  Because this is a wildcard, it
       doesn't matter if the user does not
       actually link against crtbegin.o; the
       linker won't look for a file to match a
       wildcard.  The wildcard also means that it
       doesn't matter which directory crtbegin.o
       is in.  */
    KEEP (*crtbegin.o(.ctors))
    KEEP (*crtbegin?.o(.ctors))
    /* We don't want to include the .ctor section from
       from the crtend.o file until after the sorted ctors.
       The .ctor section from the crtend file contains the
       end of ctors marker and it must be last */
    KEEP (*(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors))
    KEEP (*(SORT(.ctors.*)))
    KEEP (*(.ctors))
    __CTOR_END__ = .;
  } > m_text

  .dtors :
  {
    __DTOR_LIST__ = .;
    KEEP (*crtbegin.o(.dtors))
    KEEP (*crtbegin?.o(.dtors))
    KEEP (*(EXCLUDE_FILE(*crtend?.o *crtend.o) .dtors))
    KEEP (*(SORT(.dtors.*)))
    KEEP (*(.dtors))
    __DTOR_END__ = .;
  } > m_text

  .preinit_array :
  {
    PROVIDE_HIDDEN (__preinit_array_start = .);
    KEEP (*(.preinit_array*))
    PROVIDE_HIDDEN (__preinit_array_end = .);
  } > m_text

  .init_array :
  {
    PROVIDE_HIDDEN (__init_array_start = .);
    KEEP (*(SORT(.init_array.*)))
    KEEP (*(.init_array*))
    PROVIDE_HIDDEN (__init_array_end = .);
  } > m_text

  .fini_array :
  {
    PROVIDE_HIDDEN (__fini_array_start = .);
    KEEP (*(SORT(.fini_array.*)))
    KEEP (*(.fini_array*))
    PROVIDE_HIDDEN (__fini_array_end = .);
  } > m_text

  __etext = .;    /* define a global symbol at end of code */
  __DATA_ROM = .; /* Symbol is used by startup for data initialization */

  .interrupts_ram :
  {
    . = ALIGN(4);
    __VECTOR_RAM__ = .;
    __interrupts_ram_start__ = .; /* Create a global symbol at data start */
    *(.m_interrupts_ram)     /* This is a user defined section */
    . += M_VECTOR_RAM_SIZE;
    . = ALIGN(4);
    __interrupts_ram_end__ = .; /* Define a global symbol at data end */
  } > m_data

  __VECTOR_RAM = DEFINED(__ram_vector_table__) ? __VECTOR_RAM__ : ORIGIN(m_interrupts);
  __RAM_VECTOR_TABLE_SIZE_BYTES = DEFINED(__ram_vector_table__) ? (__interrupts_ram_end__ - __interrupts_ram_start__) : 0x0;

  .data : AT(__DATA_ROM)
  {
    . = ALIGN(4);
    __DATA_RAM = .;
    __data_start__ = .;      /* create a global symbol at data start */
    *(.data)                 /* .data sections */
    *(.data*)                /* .data* sections */
    KEEP(*(.jcr*))
    . = ALIGN(4);
    __data_end__ = .;        /* define a global symbol at data end */
  } > m_data

  __DATA_END = __DATA_ROM + (__data_end__ - __data_start__);
  text_end = ORIGIN(m_text) + LENGTH(m_text);
  ASSERT(__DATA_END <= text_end, "region m_text overflowed with text and data")

  USB_RAM_GAP = DEFINED(__usb_ram_size__) ? __usb_ram_size__ : 0x800;
  /* Uninitialized data section */
  .bss :
  {
    /* This is used by the startup in order to initialize the .bss section */
    . = ALIGN(4);
    __START_BSS = .;
    __bss_start__ = .;
    *(.bss)
    *(.bss*)
    . = ALIGN(512);
    USB_RAM_START = .;
    . += USB_RAM_GAP;
    *(COMMON)
    . = ALIGN(4);
    __bss_end__ = .;
    __END_BSS = .;
  } > m_data

  .heap :
  {
    . = ALIGN(8);
    __end__ = .;
    PROVIDE(end = .);
    __HeapBase = .;
    . += HEAP_SIZE;
    __HeapLimit = .;
    __heap_limit = .; /* Add for _sbrk */
  } > m_data_2

  .stack :
  {
    . = ALIGN(8);
    . += STACK_SIZE;
  } > m_data_2

  m_usb_bdt USB_RAM_START (NOLOAD) :
  {
    *(m_usb_bdt)
    USB_RAM_BDT_END = .;
  }

  m_usb_global USB_RAM_BDT_END (NOLOAD) :
  {
    *(m_usb_global)
  }

  /* Initializes stack on the end of block */
  __StackTop   = ORIGIN(m_data_2) + LENGTH(m_data_2);
  __StackLimit = __StackTop - STACK_SIZE;
  PROVIDE(__stack = __StackTop);

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

  ASSERT(__StackLimit >= __HeapLimit, "region m_data_2 overflowed with stack and heap")
}

使用此实现，引导加载程序不会加载应用程序并会重新启动。我假设错误来 self 的 .bin 中错误的内存映射。

内存映射应符合以下条件:

我当前使用的 startup_XXX.s 文件:

    .syntax unified
    .arch armv7-m

    .section .isr_vector, "a"
    .align 2
    .globl __isr_vector
__isr_vector:
    .long   __StackTop                                      /* Top of Stack */
    .long   Reset_Handler                                   /* Reset Handler */
    .long   NMI_Handler                                     /* NMI Handler*/
    .long   HardFault_Handler                               /* Hard Fault Handler*/
    .long   MemManage_Handler                               /* MPU Fault Handler*/
    .long   BusFault_Handler                                /* Bus Fault Handler*/
    .long   UsageFault_Handler                              /* Usage Fault Handler*/
    .long   0                                               /* Reserved*/
    .long   0                                               /* Reserved*/
    .long   0                                               /* Reserved*/
    .long   0                                               /* Reserved*/
    .long   SVC_Handler                                     /* SVCall Handler*/
    .long   DebugMon_Handler                                /* Debug Monitor Handler*/
    .long   0                                               /* Reserved*/
    .long   PendSV_Handler                                  /* PendSV Handler*/
    .long   SysTick_Handler                                 /* SysTick Handler*/

                                                            /* External Interrupts*/
    .long   DMA0_DMA16_IRQHandler                           /* DMA Channel 0, 16 Transfer Complete*/
    .long   DMA1_DMA17_IRQHandler                           /* DMA Channel 1, 17 Transfer Complete*/
    .long   DMA2_DMA18_IRQHandler                           /* DMA Channel 2, 18 Transfer Complete*/
    .long   DMA3_DMA19_IRQHandler                           /* DMA Channel 3, 19 Transfer Complete*/
    .long   DMA4_DMA20_IRQHandler                           /* DMA Channel 4, 20 Transfer Complete*/
    .long   DMA5_DMA21_IRQHandler                           /* DMA Channel 5, 21 Transfer Complete*/
    .long   DMA6_DMA22_IRQHandler                           /* DMA Channel 6, 22 Transfer Complete*/
    .long   DMA7_DMA23_IRQHandler                           /* DMA Channel 7, 23 Transfer Complete*/
    .long   DMA8_DMA24_IRQHandler                           /* DMA Channel 8, 24 Transfer Complete*/
    .long   DMA9_DMA25_IRQHandler                           /* DMA Channel 9, 25 Transfer Complete*/
    .long   DMA10_DMA26_IRQHandler                          /* DMA Channel 10, 26 Transfer Complete*/
    .long   DMA11_DMA27_IRQHandler                          /* DMA Channel 11, 27 Transfer Complete*/
    .long   DMA12_DMA28_IRQHandler                          /* DMA Channel 12, 28 Transfer Complete*/
    .long   DMA13_DMA29_IRQHandler                          /* DMA Channel 13, 29 Transfer Complete*/
    .long   DMA14_DMA30_IRQHandler                          /* DMA Channel 14, 30 Transfer Complete*/
    .long   DMA15_DMA31_IRQHandler                          /* DMA Channel 15, 31 Transfer Complete*/
    .long   DMA_Error_IRQHandler                            /* DMA Error Interrupt*/
    .long   MCM_IRQHandler                                  /* Normal Interrupt*/
    .long   FTFE_IRQHandler                                 /* FTFE Command complete interrupt*/
    .long   Read_Collision_IRQHandler                       /* Read Collision Interrupt*/
    .long   LVD_LVW_IRQHandler                              /* Low Voltage Detect, Low Voltage Warning*/
    .long   LLWU_IRQHandler                                 /* Low Leakage Wakeup Unit*/
    .long   WDOG_EWM_IRQHandler                             /* WDOG Interrupt*/
    .long   RNG_IRQHandler                                  /* RNG Interrupt*/
    .long   I2C0_IRQHandler                                 /* I2C0 interrupt*/
    .long   I2C1_IRQHandler                                 /* I2C1 interrupt*/
    .long   SPI0_IRQHandler                                 /* SPI0 Interrupt*/
    .long   SPI1_IRQHandler                                 /* SPI1 Interrupt*/
    .long   I2S0_Tx_IRQHandler                              /* I2S0 transmit interrupt*/
    .long   I2S0_Rx_IRQHandler                              /* I2S0 receive interrupt*/
    .long   Reserved46_IRQHandler                           /* Reserved interrupt 46*/
    .long   UART0_RX_TX_IRQHandler                          /* UART0 Receive/Transmit interrupt*/
    .long   UART0_ERR_IRQHandler                            /* UART0 Error interrupt*/
    .long   UART1_RX_TX_IRQHandler                          /* UART1 Receive/Transmit interrupt*/
    .long   UART1_ERR_IRQHandler                            /* UART1 Error interrupt*/
    .long   UART2_RX_TX_IRQHandler                          /* UART2 Receive/Transmit interrupt*/
    .long   UART2_ERR_IRQHandler                            /* UART2 Error interrupt*/
    .long   UART3_RX_TX_IRQHandler                          /* UART3 Receive/Transmit interrupt*/
    .long   UART3_ERR_IRQHandler                            /* UART3 Error interrupt*/
    .long   ADC0_IRQHandler                                 /* ADC0 interrupt*/
    .long   CMP0_IRQHandler                                 /* CMP0 interrupt*/
    .long   CMP1_IRQHandler                                 /* CMP1 interrupt*/
    .long   FTM0_IRQHandler                                 /* FTM0 fault, overflow and channels interrupt*/
    .long   FTM1_IRQHandler                                 /* FTM1 fault, overflow and channels interrupt*/
    .long   FTM2_IRQHandler                                 /* FTM2 fault, overflow and channels interrupt*/
    .long   CMT_IRQHandler                                  /* CMT interrupt*/
    .long   RTC_IRQHandler                                  /* RTC interrupt*/
    .long   RTC_Seconds_IRQHandler                          /* RTC seconds interrupt*/
    .long   PIT0_IRQHandler                                 /* PIT timer channel 0 interrupt*/
    .long   PIT1_IRQHandler                                 /* PIT timer channel 1 interrupt*/
    .long   PIT2_IRQHandler                                 /* PIT timer channel 2 interrupt*/
    .long   PIT3_IRQHandler                                 /* PIT timer channel 3 interrupt*/
    .long   PDB0_IRQHandler                                 /* PDB0 Interrupt*/
    .long   USB0_IRQHandler                                 /* USB0 interrupt*/
    .long   USBDCD_IRQHandler                               /* USBDCD Interrupt*/
    .long   Reserved71_IRQHandler                           /* Reserved interrupt 71*/
    .long   DAC0_IRQHandler                                 /* DAC0 interrupt*/
    .long   MCG_IRQHandler                                  /* MCG Interrupt*/
    .long   LPTMR0_IRQHandler                               /* LPTimer interrupt*/
    .long   PORTA_IRQHandler                                /* Port A interrupt*/
    .long   PORTB_IRQHandler                                /* Port B interrupt*/
    .long   PORTC_IRQHandler                                /* Port C interrupt*/
    .long   PORTD_IRQHandler                                /* Port D interrupt*/
    .long   PORTE_IRQHandler                                /* Port E interrupt*/
    .long   SWI_IRQHandler                                  /* Software interrupt*/
    .long   SPI2_IRQHandler                                 /* SPI2 Interrupt*/
    .long   UART4_RX_TX_IRQHandler                          /* UART4 Receive/Transmit interrupt*/
    .long   UART4_ERR_IRQHandler                            /* UART4 Error interrupt*/
    .long   Reserved84_IRQHandler                           /* Reserved interrupt 84*/
    .long   Reserved85_IRQHandler                           /* Reserved interrupt 85*/
    .long   CMP2_IRQHandler                                 /* CMP2 interrupt*/
    .long   FTM3_IRQHandler                                 /* FTM3 fault, overflow and channels interrupt*/
    .long   DAC1_IRQHandler                                 /* DAC1 interrupt*/
    .long   ADC1_IRQHandler                                 /* ADC1 interrupt*/
    .long   I2C2_IRQHandler                                 /* I2C2 interrupt*/
    .long   CAN0_ORed_Message_buffer_IRQHandler             /* CAN0 OR'd message buffers interrupt*/
    .long   CAN0_Bus_Off_IRQHandler                         /* CAN0 bus off interrupt*/
    .long   CAN0_Error_IRQHandler                           /* CAN0 error interrupt*/
    .long   CAN0_Tx_Warning_IRQHandler                      /* CAN0 Tx warning interrupt*/
    .long   CAN0_Rx_Warning_IRQHandler                      /* CAN0 Rx warning interrupt*/
    .long   CAN0_Wake_Up_IRQHandler                         /* CAN0 wake up interrupt*/
    .long   SDHC_IRQHandler                                 /* SDHC interrupt*/
    .long   ENET_1588_Timer_IRQHandler                      /* Ethernet MAC IEEE 1588 Timer Interrupt*/
    .long   ENET_Transmit_IRQHandler                        /* Ethernet MAC Transmit Interrupt*/
    .long   ENET_Receive_IRQHandler                         /* Ethernet MAC Receive Interrupt*/
    .long   ENET_Error_IRQHandler                           /* Ethernet MAC Error and miscelaneous Interrupt*/
    .long   LPUART0_IRQHandler                              /* LPUART0 status/error interrupt*/
    .long   TSI0_IRQHandler                                 /* TSI0 interrupt*/
    .long   TPM1_IRQHandler                                 /* TPM1 fault, overflow and channels interrupt*/
    .long   TPM2_IRQHandler                                 /* TPM2 fault, overflow and channels interrupt*/
    .long   USBHSDCD_IRQHandler                             /* USBHSDCD, USBHS Phy Interrupt*/
    .long   I2C3_IRQHandler                                 /* I2C3 interrupt*/
    .long   CMP3_IRQHandler                                 /* CMP3 interrupt*/
    .long   USBHS_IRQHandler                                /* USB high speed OTG interrupt*/
    .long   CAN1_ORed_Message_buffer_IRQHandler             /* CAN1 OR'd message buffers interrupt*/
    .long   CAN1_Bus_Off_IRQHandler                         /* CAN1 bus off interrupt*/
    .long   CAN1_Error_IRQHandler                           /* CAN1 error interrupt*/
    .long   CAN1_Tx_Warning_IRQHandler                      /* CAN1 Tx warning interrupt*/
    .long   CAN1_Rx_Warning_IRQHandler                      /* CAN1 Rx warning interrupt*/
    .long   CAN1_Wake_Up_IRQHandler                         /* CAN1 wake up interrupt*/
    .long   DefaultISR                                      /* 116*/
    .long   DefaultISR                                      /* 117*/
    .long   DefaultISR                                      /* 118*/
    .long   DefaultISR                                      /* 119*/
    .long   DefaultISR                                      /* 120*/
    .long   DefaultISR                                      /* 121*/
    .long   DefaultISR                                      /* 122*/
    .long   DefaultISR                                      /* 123*/
    .long   DefaultISR                                      /* 124*/
    .long   DefaultISR                                      /* 125*/
    (...)
    .long   DefaultISR                                      /* 245*/
    .long   DefaultISR                                      /* 246*/
    .long   DefaultISR                                      /* 247*/
    .long   DefaultISR                                      /* 248*/
    .long   DefaultISR                                      /* 249*/
    .long   DefaultISR                                      /* 250*/
    .long   DefaultISR                                      /* 251*/
    .long   DefaultISR                                      /* 252*/
    .long   DefaultISR                                      /* 253*/
    .long   DefaultISR                                      /* 254*/
    .long   0xFFFFFFFF                                      /*  Reserved for user TRIM value*/

    .size    __isr_vector, . - __isr_vector

/* Flash Configuration */
    .section .FlashConfig, "a"
    .long 0xFFFFFFFF
    .long 0xFFFFFFFF
    .long 0xFFFFFFFF
    .long 0xFFFFFFFE

    .text
    .thumb

/* Reset Handler */

    .thumb_func
    .align 2
    .globl   Reset_Handler
    .weak    Reset_Handler
    .type    Reset_Handler, %function
Reset_Handler:
    cpsid   i               /* Mask interrupts */
    .equ    VTOR, 0xE000ED08
    ldr     r0, =VTOR
    ldr     r1, =__isr_vector
    str     r1, [r0]
    ldr     r2, [r1]
    msr     msp, r2
#ifndef __NO_SYSTEM_INIT
    ldr   r0,=SystemInit
    blx   r0
#endif
/*     Loop to copy data from read only memory to RAM. The ranges
 *      of copy from/to are specified by following symbols evaluated in
 *      linker script.
 *      __etext: End of code section, i.e., begin of data sections to copy from.
 *      __data_start__/__data_end__: RAM address range that data should be
 *      copied to. Both must be aligned to 4 bytes boundary.  */

    ldr    r1, =__etext
    ldr    r2, =__data_start__
    ldr    r3, =__data_end__

#if 1
/* Here are two copies of loop implemenations. First one favors code size
 * and the second one favors performance. Default uses the first one.
 * Change to "#if 0" to use the second one */
.LC0:
    cmp     r2, r3
    ittt    lt
    ldrlt   r0, [r1], #4
    strlt   r0, [r2], #4
    blt    .LC0
#else
    subs    r3, r2
    ble    .LC1
.LC0:
    subs    r3, #4
    ldr    r0, [r1, r3]
    str    r0, [r2, r3]
    bgt    .LC0
.LC1:
#endif

#ifdef __STARTUP_CLEAR_BSS
/*     This part of work usually is done in C library startup code. Otherwise,
 *     define this macro to enable it in this startup.
 *
 *     Loop to zero out BSS section, which uses following symbols
 *     in linker script:
 *      __bss_start__: start of BSS section. Must align to 4
 *      __bss_end__: end of BSS section. Must align to 4
 */
    ldr r1, =__bss_start__
    ldr r2, =__bss_end__

    movs    r0, 0
.LC2:
    cmp     r1, r2
    itt    lt
    strlt   r0, [r1], #4
    blt    .LC2
#endif /* __STARTUP_CLEAR_BSS */

    cpsie   i               /* Unmask interrupts */
#ifndef __START
#define __START _start
#endif
#ifndef __ATOLLIC__
    ldr   r0,=__START
    blx   r0
#else
    ldr   r0,=__libc_init_array
    blx   r0
    ldr   r0,=main
    bx    r0
#endif
    .pool

[无法粘贴整个文件]

我解决问题的尝试来自 this tutorial .

Answer 1

启动函数应该放在0x80000位置，这样bootloader才能正确执行。

另一个问题是中断。因为你有一个引导加载程序，我猜它正在运行整个程序生命周期，你不应该替换它的中断 vector 。引导加载程序可能具有一些设置中断的功能，因此您应该使用这些功能，而不是重新定位 ISR vector 。

---

将启动函数放在已知地址:

由于您使用的是 MCUXpresso 和 KDS，我想您使用的是 NXP 提供的基于 GCC 的工具链。

如果是这样，您将需要使用 sections 以便在定义的地址设置函数。在SDK中，启动函数位于文件startup_XXX.S中，在我的文件中(我不知道他们是否总是使用相同的命名)它被称为Reset_Handler。您也可以从您的 ISR vector 中找到它，因为它是第二个条目(重置条目)。

在我的例子中，它的定义如下:

.section .reset_handler_section, "a"  //EDIT 3: This is the line added
.thumb_func
    .align 2
    .globl   Reset_Handler
    .weak    Reset_Handler
    .type    Reset_Handler, %function
Reset_Handler:
    //Actual reset code follows

您的 ASM 代码中应该有类似的东西。

现在，一旦您知道哪个是启动函数，就应该将它放在 0x80000 处。这是在链接器文件的 SECTIONS 部分中完成的。

但首先，您的新内存映射应该只包括您可以修改的内存，这是您所附图像中称为“应用程序区域”的部分。

因此，我们应用程序的内存映射应该是:

MEMORY
{
  m_text                (RX)  : ORIGIN = 0x00080000, LENGTH = 0x00080000
  m_data                (RWX)  : ORIGIN = 0x20000000, LENGTH = 0x00030000
}

警告:您应该知道您的数据 (m_data) 可以在 RAM 中的何处开始，因为您不想覆盖引导加载程序数据。你没有在你的图像中显示它，所以我只是在 RAM 中选择了一个 ORIGIN，但你应该检查一下。

另请注意，没有中断或 flash_config 部分。我假设引导加载程序已经有了这些，所以您不需要再次添加它们。

一旦定义了内存映射，就可以将所有程序添加到其中:

SECTIONS
{
  /* The startup code*/
    .startup_text :
  {
    . = ALIGN(4);
    KEEP(*(.reset_handler_section)) /* Startup data */ /*EDIT 3: This is the modification*/
    KEEP(*(.isr_vector))     /* EDIT 6: Startup code. It is needed in order to avoid modifying source files. It is not used, since the reset vector is the defined in the Bootloader build */
    *(.text)                 /* .text sections (code) */
    *(.text*)                /* .text* sections (code) */
    *(.rodata)               /* .rodata sections (constants, strings, etc.) */
    *(.rodata*)              /* .rodata* sections (constants, strings, etc.) */
    *(.glue_7)               /* glue arm to thumb code */
    *(.glue_7t)              /* glue thumb to arm code */
    KEEP (*(.init))  /*EDIT 2: The init section. If there are more 
                      * sections like this, just keep adding them here.
                      */
  } > m_text

    /*EDIT 5. Added entire section*/
  .ARM :
  {
    __exidx_start = .;
    *(.ARM.exidx*)
    __exidx_end = .;
  } > m_text

  __DATA_ROM = .;          /* Symbol is used by startup for data initialization */ /*EDIT 7: This symbol must be placed at the end of the text sections, so the data can follow all the code in ROM*/
  __etext = .;    /* define a global symbol at end of code */ /*EDIT 4*/

  /*The application variables and other data in RAM*/
  .data : AT(__DATA_ROM)
  {
    . = ALIGN(4);
    __DATA_RAM = .;
    __data_start__ = .;      /* create a global symbol at data start */
    *(.data)                 /* .data sections */
    *(.data*)                /* .data* sections */
    KEEP(*(.jcr*))
    KEEP(*(.ramSection))
    . = ALIGN(4);
    __data_end__ = .;        /* define a global symbol at data end */
  } > m_data

  /* Uninitialized data section */
  .bss :
  {
    /* This is used by the startup in order to initialize the .bss section */
    . = ALIGN(4);
    __START_BSS = .;
    __bss_start__ = .;
    *(.bss)
    *(.bss*)
    *(COMMON)
    . = ALIGN(4);
    __bss_end__ = .;
    __END_BSS = .;
  } > m_data

}

作为一个小解释，我们告诉链接器将“.startup_text”(这可以是任何名称)部分内的所有内容放入m_text 内存中，始终按顺序放置。因此，在 m_text 的第一个地址(即 0x80000)中，它将放置 Reset_Handler。在它之后，它将放置所有其他函数 (.text) 和常量数据 (rodata)。

我们还将符号__DATA_ROM 定义为该段的最后地址。在所有常量数据之后，我们还附加了初始化数据。此数据具有将进入 ROM 的常量值，但链接器还应在 RAM 中为它们保留内存，以便能够修改它们。这是在 data 部分中完成的。

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编辑 1:为了让链接器知道从哪里开始您的程序，从而能够查看需要什么代码，您必须告诉它哪一个是您程序的启动点，因为链接器不了解芯片特定的硬件(如复位 vector 入口)。这是通过将其添加到链接器文件的开头，MEMORY 部分之前来完成的:

/* Entry Point */
ENTRY(Reset_Handler)

STACK_SIZE = 0x0400;
M_VECTOR_RAM_SIZE = 0x0400;

我不知道尺寸的定义是否真的需要，但以防万一我也把它们放在这里。