相对于ARM上一代的主流ARM7/ARM9内核架构,新一代Cortex内核架构的启动方式有了比较大的变化。ARM7/ARM9内核的控制器在复位后,CPU会从存储
空间的绝对地址0x000000取出第一条指令执行复位中断服务程序的方式启动,即固定了复位后的起始地址为0x000000(PC = 0x000000)同时中断向量表
的位置并不是固定的。而Cortex-M3内核则正好相反,有3种情况:
1、通过boot引脚设置可以将中断向量表定位于SRAM区,即起始地址为0x2000000,同时复位后PC指针位于0x2000000处;
2、 通过boot引脚设置可以将中断向量表定位于FLASH区,即起始地址为0x8000000,同时复位后PC指针位于0x8000000处;
3、 通过boot引脚设置可以将中断向量表定位于内置Bootloader区,本文不对这种情况做论述;
而Cortex-M3内核规定,起始地址必须存放堆顶指针,而第二个地址则必须存放复位中断入口向量地址,这样在Cortex-M3内核复位后,会自动从起始地址
的下一个32位空间取出复位中断入口向量,跳转执行复位中断服务程序。对比ARM7/ARM9内核,Cortex-M3内核则是固定了中断向量表的位置而起始地址
是可变化的。
有了上述准备只是后,下面以STM32的2.02固件库提供的启动文件“stm32f10x_vector.s”为模板,对STM32的启动过程做一个简要而全面的解析。
程序清单一:
- ;文件“stm32f10x_vector.s”,其中注释为行号
- DATA_IN_ExtSRAM EQU 0 ;1
- Stack_Size EQU 0x00000400 ;2
- AREA STACK, NOINIT, READWRITE, ALIGN = 3 ;3
- Stack_Mem SPACE Stack_Size ;4
- __initial_sp ;5
- Heap_Size EQU 0x00000400 ;6
- AREA HEAP, NOINIT, READWRITE, ALIGN = 3 ;7
- __heap_base ;8
- Heap_Mem SPACE Heap_Size ;9
- __heap_limit ;10
- THUMB ;11
- PRESERVE8 ;12
- IMPORT NMIException ;13
- IMPORT HardFaultException ;14
- IMPORT MemManageException ;15
- IMPORT BusFaultException ;16
- IMPORT UsageFaultException ;17
- IMPORT SVCHandler ;18
- IMPORT DebugMonitor ;19
- IMPORT PendSVC ;20
- IMPORT SysTickHandler ;21
- IMPORT WWDG_IRQHandler ;22
- IMPORT PVD_IRQHandler ;23
- IMPORT TAMPER_IRQHandler ;24
- IMPORT RTC_IRQHandler ;25
- IMPORT FLASH_IRQHandler ;26
- IMPORT RCC_IRQHandler ;27
- IMPORT EXTI0_IRQHandler ;28
- IMPORT EXTI1_IRQHandler ;29
- IMPORT EXTI2_IRQHandler ;30
- IMPORT EXTI3_IRQHandler ;31
- IMPORT EXTI4_IRQHandler ;32
- IMPORT DMA1_Channel1_IRQHandler ;33
- IMPORT DMA1_Channel2_IRQHandler ;34
- IMPORT DMA1_Channel3_IRQHandler ;35
- IMPORT DMA1_Channel4_IRQHandler ;36
- IMPORT DMA1_Channel5_IRQHandler ;37
- IMPORT DMA1_Channel6_IRQHandler ;38
- IMPORT DMA1_Channel7_IRQHandler ;39
- IMPORT ADC1_2_IRQHandler ;40
- IMPORT USB_HP_CAN_TX_IRQHandler ;41
- IMPORT USB_LP_CAN_RX0_IRQHandler ;42
- IMPORT CAN_RX1_IRQHandler ;43
- IMPORT CAN_SCE_IRQHandler ;44
- IMPORT EXTI9_5_IRQHandler ;45
- IMPORT TIM1_BRK_IRQHandler ;46
- IMPORT TIM1_UP_IRQHandler ;47
- IMPORT TIM1_TRG_COM_IRQHandler ;48
- IMPORT TIM1_CC_IRQHandler ;49
- IMPORT TIM2_IRQHandler ;50
- IMPORT TIM3_IRQHandler ;51
- IMPORT TIM4_IRQHandler ;52
- IMPORT I2C1_EV_IRQHandler ;53
- IMPORT I2C1_ER_IRQHandler ;54
- IMPORT I2C2_EV_IRQHandler ;55
- IMPORT I2C2_ER_IRQHandler ;56
- IMPORT SPI1_IRQHandler ;57
- IMPORT SPI2_IRQHandler ;58
- IMPORT USART1_IRQHandler ;59
- IMPORT USART2_IRQHandler ;60
- IMPORT USART3_IRQHandler ;61
- IMPORT EXTI15_10_IRQHandler ;62
- IMPORT RTCAlarm_IRQHandler ;63
- IMPORT USBWakeUp_IRQHandler ;64
- IMPORT TIM8_BRK_IRQHandler ;65
- IMPORT TIM8_UP_IRQHandler ;66
- IMPORT TIM8_TRG_COM_IRQHandler ;67
- IMPORT TIM8_CC_IRQHandler ;68
- IMPORT ADC3_IRQHandler ;69
- IMPORT FSMC_IRQHandler ;70
- IMPORT SDIO_IRQHandler ;71
- IMPORT TIM5_IRQHandler ;72
- IMPORT SPI3_IRQHandler ;73
- IMPORT UART4_IRQHandler ;74
- IMPORT UART5_IRQHandler ;75
- IMPORT TIM6_IRQHandler ;76
- IMPORT TIM7_IRQHandler ;77
- IMPORT DMA2_Channel1_IRQHandler ;78
- IMPORT DMA2_Channel2_IRQHandler ;79
- IMPORT DMA2_Channel3_IRQHandler ;80
- IMPORT DMA2_Channel4_5_IRQHandler ;81
- AREA RESET, DATA, READONLY ;82
- EXPORT __Vectors ;83
- __Vectors ;84
- DCD __initial_sp ;85
- DCD Reset_Handler ;86
- DCD NMIException ;87
- DCD HardFaultException ;88
- DCD MemManageException ;89
- DCD BusFaultException ;90
- DCD UsageFaultException ;91
- DCD 0 ;92
- DCD 0 ;93
- DCD 0 ;94
- DCD 0 ;95
- DCD SVCHandler ;96
- DCD DebugMonitor ;97
- DCD 0 ;98
- DCD PendSVC ;99
- DCD SysTickHandler ;100
- DCD WWDG_IRQHandler ;101
- DCD PVD_IRQHandler ;102
- DCD TAMPER_IRQHandler ;103
- DCD RTC_IRQHandler ;104
- DCD FLASH_IRQHandler ;105
- DCD RCC_IRQHandler ;106
- DCD EXTI0_IRQHandler ;107
- DCD EXTI1_IRQHandler ;108
- DCD EXTI2_IRQHandler ;109
- DCD EXTI3_IRQHandler ;110
- DCD EXTI4_IRQHandler ;111
- DCD DMA1_Channel1_IRQHandler ;112
- DCD DMA1_Channel2_IRQHandler ;113
- DCD DMA1_Channel3_IRQHandler ;114
- DCD DMA1_Channel4_IRQHandler ;115
- DCD DMA1_Channel5_IRQHandler ;116
- DCD DMA1_Channel6_IRQHandler ;117
- DCD DMA1_Channel7_IRQHandler ;118
- DCD ADC1_2_IRQHandler ;119
- DCD USB_HP_CAN_TX_IRQHandler ;120
- DCD USB_LP_CAN_RX0_IRQHandler ;121
- DCD CAN_RX1_IRQHandler ;122
- DCD CAN_SCE_IRQHandler ;123
- DCD EXTI9_5_IRQHandler ;124
- DCD TIM1_BRK_IRQHandler ;125
- DCD TIM1_UP_IRQHandler ;126
- DCD TIM1_TRG_COM_IRQHandler ;127
- DCD TIM1_CC_IRQHandler ;128
- DCD TIM2_IRQHandler ;129
- DCD TIM3_IRQHandler ;130
- DCD TIM4_IRQHandler ;131
- DCD I2C1_EV_IRQHandler ;132
- DCD I2C1_ER_IRQHandler ;133
- DCD I2C2_EV_IRQHandler ;134
- DCD I2C2_ER_IRQHandler ;135
- DCD SPI1_IRQHandler ;136
- DCD SPI2_IRQHandler ;137
- DCD USART1_IRQHandler ;138
- DCD USART2_IRQHandler ;139
- DCD USART3_IRQHandler ;140
- DCD EXTI15_10_IRQHandler ;141
- DCD RTCAlarm_IRQHandler ;142
- DCD USBWakeUp_IRQHandler ;143
- DCD TIM8_BRK_IRQHandler ;144
- DCD TIM8_UP_IRQHandler ;145
- DCD TIM8_TRG_COM_IRQHandler ;146
- DCD TIM8_CC_IRQHandler ;147
- DCD ADC3_IRQHandler ;148
- DCD FSMC_IRQHandler ;149
- DCD SDIO_IRQHandler ;150
- DCD TIM5_IRQHandler ;151
- DCD SPI3_IRQHandler ;152
- DCD UART4_IRQHandler ;153
- DCD UART5_IRQHandler ;154
- DCD TIM6_IRQHandler ;155
- DCD TIM7_IRQHandler ;156
- DCD DMA2_Channel1_IRQHandler ;157
- DCD DMA2_Channel2_IRQHandler ;158
- DCD DMA2_Channel3_IRQHandler ;159
- DCD DMA2_Channel4_5_IRQHandler ;160
- AREA |.text|, CODE, READONLY ;161
- Reset_Handler PROC ;162
- EXPORT Reset_Handler ;163
- IF DATA_IN_ExtSRAM ==
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