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In this particular setup (environment is ST Toolkit version 4, and board Karo TXMP-1570 with STM32MP157C MPU) the problem lies in HSE configuration. Documentation could be found in STM32MP157 Reference Manual (RM0436 Rev 6, pp.526) and Trusted Firmware ARM (TFA) synchronized with ST Toolkit version 4 (Developer Package v4 TFA/plat/st/stm32mp1/bl2_plat_setup.c l. 322 provides provide details about probable problem with clock). It is quite easy to figure out where lies source of problem - in clock or uart configuration.
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