我想在我的固件中提供内存映射（部分的开始和结束地址）：示例：我想知道user_data部分的起源在哪里（0x8800000）以及它的长度（512K） 。我在一个例子中看过它，可以在链接器脚本中定义全局变量，然后固件可以访问它（extern unsigned long GLOBAL_VAR_USER_SECTION_BEGIN）。有人可以帮助我在哪里以及如何声明全局变量？
MEMORY
{
RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
CCMRAM (rw) : ORIGIN = 0x10000000, LENGTH = 64K
/* BL (rx) : ORIGIN = 0x8000000, LENGTH = 32K */
FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 512K
USER_DATA (rw) : ORIGIN = 0x8800000, LENGTH = 512K /* user data section of 512K */
}
/*
*****************************************************************************
**
** File : LinkerScript.ld
**
** Abstract : Linker script for STM32F407VGTx Device with
** 1024KByte FLASH, 128KByte RAM
**
** Set heap size, stack size and stack location according
** to application requirements.
**
** Set memory bank area and size if external memory is used.
**
** Target : STMicroelectronics STM32
**
**
** Distribution: The file is distributed as is, without any warranty
** of any kind.
**
** (c)Copyright Ac6.
** You may use this file as-is or modify it according to the needs of your
** project. Distribution of this file (unmodified or modified) is not
** permitted. Ac6 permit registered System Workbench for MCU users the
** rights to distribute the assembled, compiled & linked contents of this
** file as part of an application binary file, provided that it is built
** using the System Workbench for MCU toolchain.
**
*****************************************************************************
*/
/* Entry Point */
ENTRY(Reset_Handler)
/* Highest address of the user mode stack */
_estack = 0x20020000; /* end of RAM */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x0; /* required amount of heap : heap is not used */
_Min_Stack_Size = 0x400; /* required amount of stack : 1K minimal stack size */
/* Specify the memory areas */
/* (xrw) : execute, read, write */
/* Flash: 1M, RAM 128K, CCMRAM: 64K */
/* Examples: xK == x'000 * 1.024 B : 128K == 131'072 (0x20'000) */
MEMORY
{
RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
CCMRAM (rw) : ORIGIN = 0x10000000, LENGTH = 64K
/* BL (rx) : ORIGIN = 0x8000000, LENGTH = 32K */
FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 512K
USER_DATA (rw) : ORIGIN = 0x8800000, LENGTH = 512K /* user data section of 512K */
}
/* 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
_siccmram = LOADADDR(.ccmram);
/* CCM-RAM section
*
* IMPORTANT NOTE!
* If initialized variables will be placed in this section,
* the startup code needs to be modified to copy the init-values.
*/
.ccmram :
{
. = ALIGN(4);
_sccmram = .; /* create a global symbol at ccmram start */
*(.ccmram)
*(.ccmram*)
. = ALIGN(4);
_eccmram = .; /* create a global symbol at ccmram end */
} >CCMRAM AT> FLASH
/* user data section : 3 different names! */
/* this places every code with this sections attribute to this section */
/* */
/* __attribute__((section(".USER_Data"))) int placed_logic() */
/* { */
/* TODO - Add your application code here */
/* return 1; */
/* } */
.user_data :
{
*(.USER_Data*);
} > USER_DATA
/* 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) }
}
答案 0 :(得分：0)
您可以在make中生成内存和链接描述符文件，然后在编译器命令行上使用变量来定义常量（即WAAAAAOUHH!!!!!!!!!!选项）。或者你甚至可以生成一个充满+'a' s的头文件：
mem.tbl：
-D生成文件：
#define或者你更进一步，使用the GNUmake table toolkit，它提供了make中的构建管理功能。它是以多平台和交叉开发/嵌入式编写的，并提供算术，表格处理和其他方便的东西。
答案 1 :(得分：-1)
可以轻松完成在链接描述文件中定义符号，您的文件包含一些示例。在.data部分中，已定义符号_sdata和_edata，如评论中所述（create a global symbol at data start）。
在链接描述文件中创建后，您可以使用C代码中的那些符号：
#include <stdio.h>
void display_data_start(void)
{
extern int _sdata;
printf("_sdata:%x\n", &_sdata);
}
因此&_sdata将包含.data部分的起始地址。