This paper introduces in detail STM32 The process of single chip microcomputer starting , Power on from Reset_Handle Jump to main() Process of function . among , Will focus on explanation __main Assembly code for
<>STM32 Start process
<>1. from Reset_Handler Start
Reset_Handler The code of is as follows , reference resources 《startup_stm32f10x_hd.s》
1- calculation SystemInit Function entry address , And put the address load reach R0;
R0 = [PC + 24] = [0x08000144 + 24 +4] = [0x08000160] = 0x08000495
2 – implement r0 Function pointed to , as well as SystemInit(); meanwhile , The address of the next instruction （ as well as PC+4） Save to lr(r14) in
3 – calculation __main Entry address of , and load reach r0
4 – implement __main()
<>__main Implementation process of
* __main Function content
* SP（R13） assignment
SP = [pc +12 +4] = [0x08000130 + 12 + 4] = [0x08000140] = 0x20000408
* implement __scatterload() ( address 0x08000168), and load R14, lr = 0x08000139
<>__scatterload Function execution process
<>__scatterload_copy Execution process
<>__scatterload_zeroinit Execution process
<>__main_after_scatterload Execution process
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