STM32H750 externalloader fails on SystemClock_Config.

[YNam.1]

Hi.

I'm developing with custom board which has a custom QSPI (EN25QX128A - 16Mbytes flash), so I need to make an external loader used by STM32CubeProgrammer.

First I wrote a code that interacts with QSPI and it works fine.

So I changed this code to fullfill the external loader specification.

• Init() as an entry point
• Linker configuration
• No diagnostics on unused functions

But when I connect the target board by clicking "Connect" in STM32CubeProgrammer, I checked that "Init()" is called but SystemClock_Cofnig() fails.

I tried to change clock-setting in various ways, but still get stuck in Error_Handler.

What am I missing working with External loader?

Please help me to get out of this trap.

Thanks.

[Tesla DeLorean · Accepted solution]

Perhaps that the clock / pll is already running?

​Check the local/auto variable is cleared.

USART cam be used for diagnostic output.

System can run from HSI​.