我们使用Keil一般使用ARMCC编译MCU工程代码.其实,Keil也是支持内嵌GCC编译器的.我们可以使用GCC来编译我们的工程代码.一、下载GCC编译器
GCC编译器下载地址
二、安装GCC我们可以把GCC解压到keil的安装目录下面.如下图
三、配置Keil使用GCC编译器
1、配置CC编译规则,Misc Controls 填写
-mcpu=cortex-m4 -mthumb -fdata-sections -ffunction-sections
2、Assembler中规则,Misc Controls 填写
-mcpu=cortex-m4 -mthumb
3、Linker中填写,Misc Controls 填写
-Wl,–gc-sections
-Wl,–gc-sections 这个主要是要把没有调用的函数不编译到hex中
注意:对于-mcpu=cortex-m4这个,如果你使用的是m3的芯片,则修改成-mcpu=cortex-m3
4、STM32F405NI_FLASH.ld的代码参考/********************************************************************************** File: stm32_flash.ld**** Abstract : Linker script for STM32F407VG 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**** Environment : Atollic TrueSTUDIO(R)**** Distribution: The file is distributed 揳s is,?without any warranty**of any kind.**** (c)Copyright Atollic AB.** You may use this modify it according to the needs of your** project. This file may only be built (assembled or compiled and linked)** using the Atollic TrueSTUDIO(R) product. The use of this file together** with other tools than Atollic TrueSTUDIO(R) is not permitted.********************************************************************************//* Entry Point */ENTRY(Reset_Handler)/* Highest address of the user mode stack */_estack = 0x2001FFFF; /* end of RAM *//* Generate a link error if heap and stack don’t fit into RAM */_Min_Heap_Size = 0x400;/* required amount of heap */_Min_Stack_Size = 0x800; /* required amount of stack *//* Specify the memory areas */MEMORY{FLASH (rx): ORIGIN = 0x8000000, LENGTH = 1024KRAM (xrw): ORIGIN = 0x20000000, LENGTH = 128KCCMRAM (rw): ORIGIN = 0x10000000, LENGTH = 64K}/* 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, * 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/* 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(4);PROVIDE ( end = . );PROVIDE ( _end = . );. = . + _Min_Heap_Size;. = . + _Min_Stack_Size;. = ALIGN(4); } >RAM/* Remove information from the standard libraries */ /DISCARD/ : {libc.a ( * )libm.a ( * )libgcc.a ( * ) } .ARM.attributes 0 : { *(.ARM.attributes) }}怕走崎岖路，莫想登高峰。
