STM32之知其然，知其所以然

STM32之知其然，知其所以然

/*the core document(.s)**/

; Reset handler      //复位处理
Reset_Handler    PROC
                 EXPORT  Reset_Handler             [WEAK]      //
        IMPORT  SystemInit                                     // 
        IMPORT  __main                                        
                             //load and operate
                 LDR     R0, =SystemInit
                 BLX     R0
                 LDR     R0, =__main
                 BX      R0
                 ENDP       

核心汇编文件（用途：为向量表开辟空间，并装载系统的中断处理和函数执行）

Heap_Size       EQU     0x00000200

                AREA    HEAP, NOINIT, READWRITE, ALIGN=3
__heap_base
Heap_Mem        SPACE   Heap_Size
__heap_limit

                PRESERVE8
                THUMB

; Vector Table Mapped to Address 0 at Reset
                AREA    RESET, DATA, READONLY
                EXPORT  __Vectors
                EXPORT  __Vectors_End
                EXPORT  __Vectors_Size

__Vectors       DCD     __initial_sp               ; Top of Stack       
                DCD     Reset_Handler              ; Reset Handler
                DCD     NMI_Handler                ; NMI Handler
                DCD     HardFault_Handler          ; Hard Fault Handler
                DCD     MemManage_Handler          ; MPU Fault Handler
                DCD     BusFault_Handler           ; Bus Fault Handler
                DCD     UsageFault_Handler         ; Usage Fault Handler
                DCD     0                          ; Reserved
                DCD     0                          ; Reserved
                DCD     0                          ; Reserved
                DCD     0                          ; Reserved
                DCD     SVC_Handler                ; SVCall Handler
                DCD     DebugMon_Handler           ; Debug Monitor Handler
                DCD     0                          ; Reserved
                DCD     PendSV_Handler             ; PendSV Handler
                DCD     SysTick_Handler            ; SysTick Handler