This is a kind of basic question that I can not find an answer on... It probably should be asked on stm32duino forum, but it seems to be down right now.

Does the Arduino/STM32 has an equivalent of RTC_DATA_ATTR attribute ?
This attribute is defined in Arduino/ESP32 and gives an opportunity to have some data in a RAM section that does not get overwritten in a subsequent deep sleep, shutdown and restart operations.

They implement the area by means of ld script section, like this:

#define RTC_DATA_ATTRattribute((section(".rtc.data")))

  /* RTC data section holds RTC wake stub     data/rodata, including from any source file     named rtc_wake_stub*.c and the data marked with     RTC_DATA_ATTR, RTC_RODATA_ATTR attributes.     The memory location of the data is dependent on      CONFIG_ESP32_RTCDATA_IN_FAST_MEM option.  */  .rtc.data :  {    _rtc_data_start = ABSOLUTE(.);    *(.rtc.data)    *(.rtc.rodata)    *rtc_wake_stub*.*(.data .rodata .data.* .rodata.* .bss .bss.*)    _rtc_data_end = ABSOLUTE(.);  } > rtc_data_location

Full content:
https://github.com/espressif/arduino-esp32/blob/master/tools/sdk/ld/esp32.common.ld

Attributes:
https://github.com/espressif/arduino-esp32/blob/master/tools/sdk/include/esp32/esp_attr.h

When I look into ld scripts of Arduino/STM32 I don't see anything similar.

Is the functionality already implemented in Arduino/STM32 but with some different way ?