STM32 keil mdk啟動代碼發分析

學習STM32,看了一堆亂七八糟的文檔，準備寫程序了，先分析了下STM32的啟動代碼，看著這堆鬼鬼的匯編代碼，挺嚇人的，看看幫助，查查網路，還是不那么難懂。

1. ;//StackConfiguration
2. ;//StackSize(inBytes)<0x0-0xFFFFFFFF:8>
3. ;//
4. Stack_SizeEQU0x00000200;//定義堆棧大小
5. AREASTACK,NOINIT,READWRITE,ALIGN=3;//定義一個數據段按8字節對齊
6. Stack_MemSPACEStack_Size;//保留Stack_Size大小的堆棧空間
7. __initial_sp;//標號，代表堆棧頂部地址，后面有用
9. ;//HeapConfiguration
10. ;//HeapSize(inBytes)<0x0-0xFFFFFFFF:8>
11. ;//
12. Heap_SizeEQU0x00000020;//定義堆空間大小
13. AREAHEAP,NOINIT,READWRITE,ALIGN=3;//定義一個數據段，8字節對齊
14. __heap_base
15. Heap_MemSPACEHeap_Size;//保留Heap_Size的堆空間
16. __heap_limit;//標號，代表堆末尾地址，后面有用
18. PRESERVE8;//指示編譯器8字節對齊
19. THUMB;//指示編譯器為THUMB指令
21. ;VectorTableMappedtoAddress0atReset
22. AREARESET,DATA,READONLY;//定義只讀數據段，其實放在CODE區，位于0地址
24. EXTERNNMIException
25. EXTERNHardFaultException
26. EXTERNMemManageException
27. EXTERNBusFaultException
28. EXTERNUsageFaultException
29. EXTERNSVCHandler
30. EXTERNDebugMonitor
31. EXTERNPendSVC
32. EXTERNSysTickHandler;//聲明這些符號在外部定義，同C
33. ;//在××it.c中實現這些函數，中斷就能自動調用了
34. EXPORT__Vectors
35. __VectorsDCD__initial_sp;TopofStack//Cotex-M要求此處為堆棧頂部地址
36. DCDReset_Handler;ResetHandler
37. DCDNMIException;NMIHandler
38. DCDHardFaultException;HardFaultHandler
39. DCDMemManageException;MPUFaultHandler
40. DCDBusFaultException;BusFaultHandler
41. DCDUsageFaultException;UsageFaultHandler
42. DCD0;Reserved
43. DCD0;Reserved
44. DCD0;Reserved
45. DCD0;Reserved
46. DCDSVCHandler;SVCallHandler
47. DCDDebugMonitor;DebugMonitorHandler
48. DCD0;Reserved
49. DCDPendSVC;PendSVHandler
50. DCDSysTickHandler;SysTickHandler//一大堆的異常處理函數地址
51. ;ExternalInterrupts
52. EXTERNWWDG_IRQHandler
53. EXTERNPVD_IRQHandler
54. EXTERNTAMPER_IRQHandler
55. EXTERNRTC_IRQHandler
56. EXTERNFLASH_IRQHandler
57. EXTERNRCC_IRQHandler
58. EXTERNEXTI0_IRQHandler
59. EXTERNEXTI1_IRQHandler
60. EXTERNEXTI2_IRQHandler
61. EXTERNEXTI3_IRQHandler
62. EXTERNEXTI4_IRQHandler
63. EXTERNDMAChannel1_IRQHandler
64. EXTERNDMAChannel2_IRQHandler
65. EXTERNDMAChannel3_IRQHandler
66. EXTERNDMAChannel4_IRQHandler
67. EXTERNDMAChannel5_IRQHandler
68. EXTERNDMAChannel6_IRQHandler
69. EXTERNDMAChannel7_IRQHandler
70. EXTERNADC_IRQHandler
71. EXTERNUSB_HP_CAN_TX_IRQHandler
72. EXTERNUSB_LP_CAN_RX0_IRQHandler
73. EXTERNCAN_RX1_IRQHandler
74. EXTERNCAN_SCE_IRQHandler
75. EXTERNEXTI9_5_IRQHandler
76. EXTERNTIM1_BRK_IRQHandler
77. EXTERNTIM1_UP_IRQHandler
78. EXTERNTIM1_TRG_COM_IRQHandler
79. EXTERNTIM1_CC_IRQHandler
80. EXTERNTIM2_IRQHandler
81. EXTERNTIM3_IRQHandler
82. EXTERNTIM4_IRQHandler
83. EXTERNI2C1_EV_IRQHandler
84. EXTERNI2C1_ER_IRQHandler
85. EXTERNI2C2_EV_IRQHandler
86. EXTERNI2C2_ER_IRQHandler
87. EXTERNSPI1_IRQHandler
88. EXTERNSPI2_IRQHandler
89. EXTERNUSART1_IRQHandler
90. EXTERNUSART2_IRQHandler
91. EXTERNUSART3_IRQHandler
92. EXTERNEXTI15_10_IRQHandler
93. EXTERNRTCAlarm_IRQHandler
94. EXTERNUSBWakeUp_IRQHandler;//同上，
96. DCDWWDG_IRQHandler;WindowWatchdog
97. DCDPVD_IRQHandler;PVDthroughEXTILinedetect
98. DCDTAMPER_IRQHandler;Tamper
99. DCDRTC_IRQHandler;RTC
100. DCDFLASH_IRQHandler;Flash
101. DCDRCC_IRQHandler;RCC
102. DCDEXTI0_IRQHandler;EXTILine0
103. DCDEXTI1_IRQHandler;EXTILine1
104. DCDEXTI2_IRQHandler;EXTILine2
105. DCDEXTI3_IRQHandler;EXTILine3
106. DCDEXTI4_IRQHandler;EXTILine4
107. DCDDMAChannel1_IRQHandler;DMAChannel1
108. DCDDMAChannel2_IRQHandler;DMAChannel2
109. DCDDMAChannel3_IRQHandler;DMAChannel3
110. DCDDMAChannel4_IRQHandler;DMAChannel4
111. DCDDMAChannel5_IRQHandler;DMAChannel5
112. DCDDMAChannel6_IRQHandler;DMAChannel6
113. DCDDMAChannel7_IRQHandler;DMAChannel7
114. DCDADC_IRQHandler;ADC
115. DCDUSB_HP_CAN_TX_IRQHandler;USBHighPriorityorCANTX
116. DCDUSB_LP_CAN_RX0_IRQHandler;USBLowPriorityorCANRX0
117. DCDCAN_RX1_IRQHandler;CANRX1
118. DCDCAN_SCE_IRQHandler;CANSCE
119. DCDEXTI9_5_IRQHandler;EXTILine9..5
120. DCDTIM1_BRK_IRQHandler;TIM1Break
121. DCDTIM1_UP_IRQHandler;TIM1Update
122. DCDTIM1_TRG_COM_IRQHandler;TIM1TriggerandCommutation
123. DCDTIM1_CC_IRQHandler;TIM1CaptureCompare
124. DCDTIM2_IRQHandler;TIM2
125. DCDTIM3_IRQHandler;TIM3
126. DCDTIM4_IRQHandler;TIM4
127. DCDI2C1_EV_IRQHandler;I2C1Event
128. DCDI2C1_ER_IRQHandler;I2C1Error
129. DCDI2C2_EV_IRQHandler;I2C2Event
130. DCDI2C2_ER_IRQHandler;I2C2Error
131. DCDSPI1_IRQHandler;SPI1
132. DCDSPI2_IRQHandler;SPI2
133. DCDUSART1_IRQHandler;USART1
134. DCDUSART2_IRQHandler;USART2
135. DCDUSART3_IRQHandler;USART3
136. DCDEXTI15_10_IRQHandler;EXTILine15..10
137. DCDRTCAlarm_IRQHandler;RTCAlarmthroughEXTILine
138. DCDUSBWakeUp_IRQHandler;USBWakeupfromsuspend;//同上
140. AREA|.text|,CODE,READONLY;//定義代碼段
142. ;ResetHandler
143. Reset_HandlerPROC;//Rset_Handler的實現
144. EXPORTReset_Handler[WEAK];//在外部沒有定義該符號時導出該符號，見HELP中[WEAK]
145. IMPORT__main;//導入符號,__main為運行時庫提供的函數；完成堆棧，堆的初始話
146. LDRR0,=__main;//等工作，會調用下面定義的__user_initial_stackheap；
147. BXR0;//跳到__main，進入C的世界
148. ENDP
150. ALIGN
152. ;UserInitialStack&Heap
153. IF:DEF:__MICROLIB;//如果使用microlib,microlib描述見armlib.chm
155. EXPORT__initial_sp
156. EXPORT__heap_base
157. EXPORT__heap_limit;//只導出幾個定義
159. ELSE;//如果使用默認C運行時庫
161. IMPORT__use_two_region_memory
162. EXPORT__user_initial_stackheap
163. __user_initial_stackheap;//則進行堆棧和堆的賦值，在__main函數執行過程中調用。
164. LDRR0,=Heap_Mem
165. LDRR1,=(Stack_Mem+Stack_Size)
166. LDRR2,=(Heap_Mem+Heap_Size)
167. LDRR3,=Stack_Mem
168. BXLR
169. ALIGN
170. ENDIF
172. END;//OK，完了