; Amount of memory (in bytes) allocated for Stack
; Tailor this value to your application needs
; <h> Stack Configuration
; <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>
Stack_Size EQU 0x00000400 ;EQU定義棧空間的大小，棧空間由編譯器自動分配變量所占內存，該匯編語句等效於#define Stack_Size 0x00000400
;AREA 命令指示匯編器匯編一個新的代碼段或數據段。
;段是獨立的、指定的、不可見的代碼或數據塊，它們由鏈接器處理.
;段是獨立的、命名的、不可分割的代碼或數據序列。一個代碼段是生成一個應用程序的最低要求
;默認情況下，ELF 段在四字節邊界上對齊。expression 可以擁有 0 到 31 的任何整數。
;段在 2expression 字節邊界上對齊
AREA STACK, NOINIT, READWRITE, ALIGN=3 ;AREA開辟棧段，段名為STACK，棧屬性為NOINIT, READWRITE，8字節對齊
; 說明: Cortex-M4的指令地址要求是字邊界對齊（4字節）；但是代碼段是8字節邊界對齊的
Stack_Mem SPACE Stack_Size ;SPACE分配連續的棧存儲空間，大小為0x00000400(1K)，把首地址賦給Stack_Mem
__initial_sp ;初始化堆棧指針，指向堆棧頂。
; 此處有個一個問題討論，關於棧頂在RAM中所處位置問題，很多初學者一直以為是編譯器特意放在HEAP段之后是有意為之，並且認為這樣可以利用heap未分配空間來防止未知的棧溢出問題
; 這種理解是錯誤的，鏈接器並不會為棧的位置做特殊的處理，而且這樣做也並不會利用heap段，在此文件的最后對堆棧的初始化代碼中可以看出他們是兩個互相獨立的數據區。此處出現的現象是因為MDK按數據段的字母順序鏈接數據段的地址的，所以此處造成了堆的地址在棧的前面的假象，不要竊以為是有某種特殊的約定。
; <h> Heap Configuration
; <o> Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>
Heap_Size EQU 0x00000200 ;EQU定義堆空間的大小，堆空間由人為手動分配變量所占內存，該匯編語句等效於#define Heap_Size 0x00000200
AREA HEAP, NOINIT, READWRITE, ALIGN=3 ;AREA開辟堆段，段名為HEAP，堆屬性為NOINIT, READWRITE，8字節對齊
__heap_base ;堆起始地址
Heap_Mem SPACE Heap_Size ;SPACE分配連續的堆存儲空間，大小為0x00000200(512Bytes)
__heap_limit ;堆終止地址，與__heap_base配合限制堆的大小
PRESERVE8 ;告訴編譯器以8字節對齊，命令指定當前文件保持棧的八字節對齊
THUMB ;告訴編譯器使用THUMB指令集，THUMB 必須位於使用新語法的任何Thumb代碼之前
;定義復位段（中斷向量表），並初始化
; Vector Table Mapped to Address 0 at Reset
AREA RESET, DATA, READONLY ;定義RESET段，數據段，只讀
EXPORT __Vectors ;聲明全局變量_Vectors，該標號可在其他文件中使用，表示中斷向量表入口地址
EXPORT __Vectors_End ;向量表終止地址
EXPORT __Vectors_Size ;向量表空間大小
;DCD 命令分配一個或多個字的存儲器，在四個字節的邊界上對齊，並定義存儲器的運行時初值。
__Vectors DCD __initial_sp ; Top of Stack ，棧頂指針，被放在向量表的開始，FLASH的0地址，復位后首先裝載棧頂指針
DCD Reset_Handler ; Reset Handler，復位異常，裝載完棧頂后，第一個執行的，並且不返回。
DCD NMI_Handler ; NMI Handler， 不可屏蔽中斷
DCD HardFault_Handler ; Hard Fault Handler，硬件錯誤中斷
DCD MemManage_Handler ; MPU Fault Handler，內存管理錯誤中斷
DCD BusFault_Handler ; Bus Fault Handler， 總線錯誤中斷，一般發生在數據訪問異常，比如fsmc訪問不當
DCD UsageFault_Handler ; Usage Fault Handler，用法錯誤中斷，一般是預取值，或者位置指令，數據處理等錯誤
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD SVC_Handler ; SVCall Handler， 系統調用異常，主要是為了調用操作系統內核服務
DCD DebugMon_Handler ; Debug Monitor Handler， 調試監視異常
DCD 0 ; Reserved
DCD PendSV_Handler ; PendSV Handler，掛起異常，此處可以用作RTOS的上下文切換異常，這是被推薦使用的，因為Cortex-M4會在異常發生時自動保存R0-R3，R12,R13(堆棧指針SP)，R14(鏈接地址，也叫返回地址LR，在異常返回時使用)，R15（程序計數器PC，為當前應用程序+4）和中斷完成時自動回復，我們只需保存R4-R11,大大減少了中斷響應和上下文切換的時間。
DCD SysTick_Handler ; SysTick Handler，滴答定時器，為操作系統內核時鍾
; External Interrupts，外部中斷
DCD WWDG_IRQHandler ; Window WatchDog
DCD PVD_IRQHandler ; PVD through EXTI Line detection
DCD TAMP_STAMP_IRQHandler ; Tamper and TimeStamps through the EXTI line
DCD RTC_WKUP_IRQHandler ; RTC Wakeup through the EXTI line
DCD FLASH_IRQHandler ; FLASH
DCD RCC_IRQHandler ; RCC
DCD EXTI0_IRQHandler ; EXTI Line0
DCD EXTI1_IRQHandler ; EXTI Line1
DCD EXTI2_IRQHandler ; EXTI Line2
DCD EXTI3_IRQHandler ; EXTI Line3
DCD EXTI4_IRQHandler ; EXTI Line4
DCD DMA1_Stream0_IRQHandler ; DMA1 Stream 0
DCD DMA1_Stream1_IRQHandler ; DMA1 Stream 1
DCD DMA1_Stream2_IRQHandler ; DMA1 Stream 2
DCD DMA1_Stream3_IRQHandler ; DMA1 Stream 3
DCD DMA1_Stream4_IRQHandler ; DMA1 Stream 4
DCD DMA1_Stream5_IRQHandler ; DMA1 Stream 5
DCD DMA1_Stream6_IRQHandler ; DMA1 Stream 6
DCD ADC_IRQHandler ; ADC1, ADC2 and ADC3s
DCD CAN1_TX_IRQHandler ; CAN1 TX
DCD CAN1_RX0_IRQHandler ; CAN1 RX0
DCD CAN1_RX1_IRQHandler ; CAN1 RX1
DCD CAN1_SCE_IRQHandler ; CAN1 SCE
DCD EXTI9_5_IRQHandler ; External Line[9:5]s
DCD TIM1_BRK_TIM9_IRQHandler ; TIM1 Break and TIM9
DCD TIM1_UP_TIM10_IRQHandler ; TIM1 Update and TIM10
DCD TIM1_TRG_COM_TIM11_IRQHandler ; TIM1 Trigger and Commutation and TIM11
DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare
DCD TIM2_IRQHandler ; TIM2
DCD TIM3_IRQHandler ; TIM3
DCD TIM4_IRQHandler ; TIM4
DCD I2C1_EV_IRQHandler ; I2C1 Event
DCD I2C1_ER_IRQHandler ; I2C1 Error
DCD I2C2_EV_IRQHandler ; I2C2 Event
DCD I2C2_ER_IRQHandler ; I2C2 Error
DCD SPI1_IRQHandler ; SPI1
DCD SPI2_IRQHandler ; SPI2
DCD USART1_IRQHandler ; USART1
DCD USART2_IRQHandler ; USART2
DCD USART3_IRQHandler ; USART3
DCD EXTI15_10_IRQHandler ; External Line[15:10]s
DCD RTC_Alarm_IRQHandler ; RTC Alarm (A and B) through EXTI Line
DCD OTG_FS_WKUP_IRQHandler ; USB OTG FS Wakeup through EXTI line
DCD TIM8_BRK_TIM12_IRQHandler ; TIM8 Break and TIM12
DCD TIM8_UP_TIM13_IRQHandler ; TIM8 Update and TIM13
DCD TIM8_TRG_COM_TIM14_IRQHandler ; TIM8 Trigger and Commutation and TIM14
DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare
DCD DMA1_Stream7_IRQHandler ; DMA1 Stream7
DCD FSMC_IRQHandler ; FSMC
DCD SDIO_IRQHandler ; SDIO
DCD TIM5_IRQHandler ; TIM5
DCD SPI3_IRQHandler ; SPI3
DCD UART4_IRQHandler ; UART4
DCD UART5_IRQHandler ; UART5
DCD TIM6_DAC_IRQHandler ; TIM6 and DAC1&2 underrun errors
DCD TIM7_IRQHandler ; TIM7
DCD DMA2_Stream0_IRQHandler ; DMA2 Stream 0
DCD DMA2_Stream1_IRQHandler ; DMA2 Stream 1
DCD DMA2_Stream2_IRQHandler ; DMA2 Stream 2
DCD DMA2_Stream3_IRQHandler ; DMA2 Stream 3
DCD DMA2_Stream4_IRQHandler ; DMA2 Stream 4
DCD ETH_IRQHandler ; Ethernet
DCD ETH_WKUP_IRQHandler ; Ethernet Wakeup through EXTI line
DCD CAN2_TX_IRQHandler ; CAN2 TX
DCD CAN2_RX0_IRQHandler ; CAN2 RX0
DCD CAN2_RX1_IRQHandler ; CAN2 RX1
DCD CAN2_SCE_IRQHandler ; CAN2 SCE
DCD OTG_FS_IRQHandler ; USB OTG FS
DCD DMA2_Stream5_IRQHandler ; DMA2 Stream 5
DCD DMA2_Stream6_IRQHandler ; DMA2 Stream 6
DCD DMA2_Stream7_IRQHandler ; DMA2 Stream 7
DCD USART6_IRQHandler ; USART6
DCD I2C3_EV_IRQHandler ; I2C3 event
DCD I2C3_ER_IRQHandler ; I2C3 error
DCD OTG_HS_EP1_OUT_IRQHandler ; USB OTG HS End Point 1 Out
DCD OTG_HS_EP1_IN_IRQHandler ; USB OTG HS End Point 1 In
DCD OTG_HS_WKUP_IRQHandler ; USB OTG HS Wakeup through EXTI
DCD OTG_HS_IRQHandler ; USB OTG HS
DCD DCMI_IRQHandler ; DCMI
DCD CRYP_IRQHandler ; CRYP crypto
DCD HASH_RNG_IRQHandler ; Hash and Rng
DCD FPU_IRQHandler ; FPU
__Vectors_End ;向量表結束標志
__Vectors_Size EQU __Vectors_End - __Vectors ;計算向量表地址空間大小
AREA |.text|, CODE, READONLY ;定義C編譯器源代碼的代碼段，只讀。|.text| 表示由 C 編譯程序產生的代碼段，或用於以某種方式與 C 庫關聯的代碼段。
; Reset handler
Reset_Handler PROC
EXPORT Reset_Handler [WEAK] ;此處[WEAK]表示弱定義，優先執行其他文件的定義
IMPORT SystemInit
IMPORT __main
LDR R0, =SystemInit ; 裝載寄存器指令
BLX R0 ; 帶鏈接的跳轉，切換指令集
LDR R0, =__main
BX R0 ; 切換指令集,main函數不返回
ENDP
; Dummy Exception Handlers (infinite loops which can be modified)
NMI_Handler PROC
EXPORT NMI_Handler [WEAK]
B . ;死循環
ENDP
HardFault_Handler\
PROC
EXPORT HardFault_Handler [WEAK]
B .
ENDP
MemManage_Handler\
PROC
EXPORT MemManage_Handler [WEAK]
B .
ENDP
BusFault_Handler\
PROC
EXPORT BusFault_Handler [WEAK]
B .
ENDP
UsageFault_Handler\
PROC
EXPORT UsageFault_Handler [WEAK]
B .
ENDP
SVC_Handler PROC
EXPORT SVC_Handler [WEAK]
B .
ENDP
DebugMon_Handler\
PROC
EXPORT DebugMon_Handler [WEAK]
B .
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler [WEAK]
B .
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler [WEAK]
B .
ENDP
Default_Handler PROC
; 輸出異常向量表標號，方便外部實現異常的具體功能 ， [WEAK] 是弱定義的意思，如果外部定義了，優先執行外部定義，否則執行下面的函數定義
EXPORT WWDG_IRQHandler [WEAK]
EXPORT PVD_IRQHandler [WEAK]
EXPORT TAMP_STAMP_IRQHandler [WEAK]
EXPORT RTC_WKUP_IRQHandler [WEAK]
EXPORT FLASH_IRQHandler [WEAK]
EXPORT RCC_IRQHandler [WEAK]
EXPORT EXTI0_IRQHandler [WEAK]
EXPORT EXTI1_IRQHandler [WEAK]
EXPORT EXTI2_IRQHandler [WEAK]
EXPORT EXTI3_IRQHandler [WEAK]
EXPORT EXTI4_IRQHandler [WEAK]
EXPORT DMA1_Stream0_IRQHandler [WEAK]
EXPORT DMA1_Stream1_IRQHandler [WEAK]
EXPORT DMA1_Stream2_IRQHandler [WEAK]
EXPORT DMA1_Stream3_IRQHandler [WEAK]
EXPORT DMA1_Stream4_IRQHandler [WEAK]
EXPORT DMA1_Stream5_IRQHandler [WEAK]
EXPORT DMA1_Stream6_IRQHandler [WEAK]
EXPORT ADC_IRQHandler [WEAK]
EXPORT CAN1_TX_IRQHandler [WEAK]
EXPORT CAN1_RX0_IRQHandler [WEAK]
EXPORT CAN1_RX1_IRQHandler [WEAK]
EXPORT CAN1_SCE_IRQHandler [WEAK]
EXPORT EXTI9_5_IRQHandler [WEAK]
EXPORT TIM1_BRK_TIM9_IRQHandler [WEAK]
EXPORT TIM1_UP_TIM10_IRQHandler [WEAK]
EXPORT TIM1_TRG_COM_TIM11_IRQHandler [WEAK]
EXPORT TIM1_CC_IRQHandler [WEAK]
EXPORT TIM2_IRQHandler [WEAK]
EXPORT TIM3_IRQHandler [WEAK]
EXPORT TIM4_IRQHandler [WEAK]
EXPORT I2C1_EV_IRQHandler [WEAK]
EXPORT I2C1_ER_IRQHandler [WEAK]
EXPORT I2C2_EV_IRQHandler [WEAK]
EXPORT I2C2_ER_IRQHandler [WEAK]
EXPORT SPI1_IRQHandler [WEAK]
EXPORT SPI2_IRQHandler [WEAK]
EXPORT USART1_IRQHandler [WEAK]
EXPORT USART2_IRQHandler [WEAK]
EXPORT USART3_IRQHandler [WEAK]
EXPORT EXTI15_10_IRQHandler [WEAK]
EXPORT RTC_Alarm_IRQHandler [WEAK]
EXPORT OTG_FS_WKUP_IRQHandler [WEAK]
EXPORT TIM8_BRK_TIM12_IRQHandler [WEAK]
EXPORT TIM8_UP_TIM13_IRQHandler [WEAK]
EXPORT TIM8_TRG_COM_TIM14_IRQHandler [WEAK]
EXPORT TIM8_CC_IRQHandler [WEAK]
EXPORT DMA1_Stream7_IRQHandler [WEAK]
EXPORT FSMC_IRQHandler [WEAK]
EXPORT SDIO_IRQHandler [WEAK]
EXPORT TIM5_IRQHandler [WEAK]
EXPORT SPI3_IRQHandler [WEAK]
EXPORT UART4_IRQHandler [WEAK]
EXPORT UART5_IRQHandler [WEAK]
EXPORT TIM6_DAC_IRQHandler [WEAK]
EXPORT TIM7_IRQHandler [WEAK]
EXPORT DMA2_Stream0_IRQHandler [WEAK]
EXPORT DMA2_Stream1_IRQHandler [WEAK]
EXPORT DMA2_Stream2_IRQHandler [WEAK]
EXPORT DMA2_Stream3_IRQHandler [WEAK]
EXPORT DMA2_Stream4_IRQHandler [WEAK]
EXPORT ETH_IRQHandler [WEAK]
EXPORT ETH_WKUP_IRQHandler [WEAK]
EXPORT CAN2_TX_IRQHandler [WEAK]
EXPORT CAN2_RX0_IRQHandler [WEAK]
EXPORT CAN2_RX1_IRQHandler [WEAK]
EXPORT CAN2_SCE_IRQHandler [WEAK]
EXPORT OTG_FS_IRQHandler [WEAK]
EXPORT DMA2_Stream5_IRQHandler [WEAK]
EXPORT DMA2_Stream6_IRQHandler [WEAK]
EXPORT DMA2_Stream7_IRQHandler [WEAK]
EXPORT USART6_IRQHandler [WEAK]
EXPORT I2C3_EV_IRQHandler [WEAK]
EXPORT I2C3_ER_IRQHandler [WEAK]
EXPORT OTG_HS_EP1_OUT_IRQHandler [WEAK]
EXPORT OTG_HS_EP1_IN_IRQHandler [WEAK]
EXPORT OTG_HS_WKUP_IRQHandler [WEAK]
EXPORT OTG_HS_IRQHandler [WEAK]
EXPORT DCMI_IRQHandler [WEAK]
EXPORT CRYP_IRQHandler [WEAK]
EXPORT HASH_RNG_IRQHandler [WEAK]
EXPORT FPU_IRQHandler [WEAK]
; 如下只是定義一個空函數
WWDG_IRQHandler
PVD_IRQHandler
TAMP_STAMP_IRQHandler
RTC_WKUP_IRQHandler
FLASH_IRQHandler
RCC_IRQHandler
EXTI0_IRQHandler
EXTI1_IRQHandler
EXTI2_IRQHandler
EXTI3_IRQHandler
EXTI4_IRQHandler
DMA1_Stream0_IRQHandler
DMA1_Stream1_IRQHandler
DMA1_Stream2_IRQHandler
DMA1_Stream3_IRQHandler
DMA1_Stream4_IRQHandler
DMA1_Stream5_IRQHandler
DMA1_Stream6_IRQHandler
ADC_IRQHandler
CAN1_TX_IRQHandler
CAN1_RX0_IRQHandler
CAN1_RX1_IRQHandler
CAN1_SCE_IRQHandler
EXTI9_5_IRQHandler
TIM1_BRK_TIM9_IRQHandler
TIM1_UP_TIM10_IRQHandler
TIM1_TRG_COM_TIM11_IRQHandler
TIM1_CC_IRQHandler
TIM2_IRQHandler
TIM3_IRQHandler
TIM4_IRQHandler
I2C1_EV_IRQHandler
I2C1_ER_IRQHandler
I2C2_EV_IRQHandler
I2C2_ER_IRQHandler
SPI1_IRQHandler
SPI2_IRQHandler
USART1_IRQHandler
USART2_IRQHandler
USART3_IRQHandler
EXTI15_10_IRQHandler
RTC_Alarm_IRQHandler
OTG_FS_WKUP_IRQHandler
TIM8_BRK_TIM12_IRQHandler
TIM8_UP_TIM13_IRQHandler
TIM8_TRG_COM_TIM14_IRQHandler
TIM8_CC_IRQHandler
DMA1_Stream7_IRQHandler
FSMC_IRQHandler
SDIO_IRQHandler
TIM5_IRQHandler
SPI3_IRQHandler
UART4_IRQHandler
UART5_IRQHandler
TIM6_DAC_IRQHandler
TIM7_IRQHandler
DMA2_Stream0_IRQHandler
DMA2_Stream1_IRQHandler
DMA2_Stream2_IRQHandler
DMA2_Stream3_IRQHandler
DMA2_Stream4_IRQHandler
ETH_IRQHandler
ETH_WKUP_IRQHandler
CAN2_TX_IRQHandler
CAN2_RX0_IRQHandler
CAN2_RX1_IRQHandler
CAN2_SCE_IRQHandler
OTG_FS_IRQHandler
DMA2_Stream5_IRQHandler
DMA2_Stream6_IRQHandler
DMA2_Stream7_IRQHandler
USART6_IRQHandler
I2C3_EV_IRQHandler
I2C3_ER_IRQHandler
OTG_HS_EP1_OUT_IRQHandler
OTG_HS_EP1_IN_IRQHandler
OTG_HS_WKUP_IRQHandler
OTG_HS_IRQHandler
DCMI_IRQHandler
CRYP_IRQHandler
HASH_RNG_IRQHandler
FPU_IRQHandler
B .
ENDP
ALIGN ; 默認是字對齊方式，也說明了代碼是4字節對齊的
;*******************************************************************************
; User Stack and Heap initialization
;*******************************************************************************
IF :DEF:__MICROLIB ;如果勾選了microlib
EXPORT __initial_sp
EXPORT __heap_base
EXPORT __heap_limit
ELSE
IMPORT __use_two_region_memory ; 兩區堆棧空間，堆和棧有各自的空間地址
EXPORT __user_initial_stackheap
__user_initial_stackheap
; 此處是初始化兩區的堆棧空間，堆是從由低到高的增長，棧是由高向低生長的，兩個是互相獨立的數據段，並不能交叉使用。
LDR R0, = Heap_Mem
LDR R1, =(Stack_Mem + Stack_Size)
LDR R2, = (Heap_Mem + Heap_Size)
LDR R3, = Stack_Mem
BX LR
ALIGN
ENDIF
END ; END 命令指示匯編器，已到達一個源文件的末尾。
;************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE*****