For ESP32-S2 and ESP32-S3 the symbol `_heap_end` must not be used as `_eheap` for dynamic memory allocation, because it points to the highest possible address that could be used for the heap, but not to the top address of the unused SRAM area. Instead, the origin and length of `dram0_0_seg` must be used to calculate the end of the heap.
Using `sectoins.ld.in` instead of a static `sections.ld`, from which the actual used `sections.ld` is generated with the C preprocessor, allows to use the configuration in `sdkconfig.h` as well as Kconfig to use a custom section layout.
