arch/risc-v/esp32c3: Create a separate heap for the RTC memory.

Signed-off-by: Abdelatif Guettouche <abdelatif.guettouche@espressif.com>

boards/risc-v/esp32c3/esp32c3-devkit/scripts/esp32c3.ld

@@ -247,6 +247,11 @@ SECTIONS
   {
     *(.rtc.data)
     *(.rtc.rodata)
+
+   /* Whatever is left from the RTC memory is used as a special heap. */
+
+    _srtc_heap = ABSOLUTE(.);
+
   } >rtc_seg
 }
 

boards/risc-v/esp32c3/esp32c3-devkit/scripts/esp32c3.template.ld

@@ -89,3 +89,6 @@ MEMORY
   REGION_ALIAS("default_code_seg", iram0_2_seg);
 #endif /* CONFIG_ESP32C3_DEVKIT_RUN_IRAM */
 
+/* Mark the end of the RTC heap (top of the RTC region) */
+
+_ertc_heap = 0x50001fff;