Hello,
there seems to be a possible build error hidden in configuration of external RTC. If configure CONFIG_RTC and CONFIG_RTC_EXTERNAL to use external RTC the build ends with following error: undefined reference to `up_rtc_initialize' This is caused by lines https://github.com/apache/nuttx/blob/master/sched/clock/clock_initialize.c#L 218 and https://github.com/apache/nuttx/blob/master/include/nuttx/arch.h#L2272 that declare and call function up_rtc_initialize which however I suppose is not used since external RTC is to be configured. This happens since pull request #5232 (https://github.com/apache/nuttx/pull/5232) which removed && ! defined(CONFIG_RTC_EXTERNAL) from files mentioned above. The quick fix so far is to add the constrain of disabled CONFIG_RTC_EXTERNAL back as suggested here (https://github.com/michallenc/incubator-nuttx/commit/bc04eb9 d891c44a6b41bb0badf34636e24e63b61). Some ideas or objections? I am not sure if there was not some other change that would require different configuration of external RTC. Best regards, Michal Lenc
