Clock source being used in NucleoF103RB

[agganitk]

Hello,
Can you tell me what clock source is being used to run the code? Is it Internal HSI or External coming from ST-LINK MCU ? I am much familier with STMCUBEIDE . I tried to go through code and ARDUINO IDE but can not find.
I having issue if I use external power supply to power the nucelo board then the code doesn't run until reset button is pressed once.

[board707]

Can you tell me what clock source is being used to run the code? Is it Internal HSI or External coming from ST-LINK MCU ?

Hi
Because there is no external St-Link on used STM32F103 "Bluepill" board, I would think that it is an internal HSI

[agganitk]

Hi..I m using NUCLEOF103RB .. it has external ST_LINK.
And as I said I have to press reset button once on giving external power supply to make the code work properly. If I give power via USB then I do not need to press reset button. I want to check clock selection code. I checked Libraries but can not find where RCC clock and registeres are declared..

[board707]

I checked Libraries but can not find where RCC clock and registeres are declared..

I think it done in the Clark's STM32 package. For generic_stm32f103c variant, see the files board.cpp and board_setup.cpp in
STM32F1/variants/generic_stm32f103c/wirish,