(nuttx) branch releases/13.1 updated: arch/risc-v/espressif: keep RTC backup data in DRAM without RTC memory

[acassis]

This is an automated email from the ASF dual-hosted git repository.

acassis pushed a commit to branch releases/13.1
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/releases/13.1 by this push:
     new ceb32679a99 arch/risc-v/espressif: keep RTC backup data in DRAM 
without RTC memory
ceb32679a99 is described below

commit ceb32679a99832af24008b1666ea67622b4fdd5f
Author: Marcio Ribeiro <marcio.ribe...@espressif.com>
AuthorDate: Wed Sep 16 14:56:15 2026 -0300

    arch/risc-v/espressif: keep RTC backup data in DRAM without RTC memory
    
    SoCs such as the ESP32-C2 have no RTC retention memory, so RTC_DATA_ATTR
    cannot be used for the persistent RTC time.  Place the backup data in DRAM
    on those chips, where the saved time does not survive deep sleep.
    
    Assisted-by: Claude:claude-opus-5
    Signed-off-by: Marcio Ribeiro <marcio.ribe...@espressif.com>
---
 arch/risc-v/src/common/espressif/esp_rtc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/risc-v/src/common/espressif/esp_rtc.c 
b/arch/risc-v/src/common/espressif/esp_rtc.c
index 16c10abe401..fdddd98c764 100644
--- a/arch/risc-v/src/common/espressif/esp_rtc.c
+++ b/arch/risc-v/src/common/espressif/esp_rtc.c
@@ -164,9 +164,15 @@ static bool g_hr_timer_enabled = false;
 
 #endif /* CONFIG_RTC_DRIVER */
 
-/* Saved data for persistent RTC time */
+/* Saved data for persistent RTC time.  Chips without RTC retention memory
+ * keep it in DRAM, so the saved time does not survive deep sleep.
+ */
 
+#ifdef SOC_RTC_MEM_SUPPORTED
 static RTC_DATA_ATTR struct esp_rtc_backup_s g_rtc_saved_data;
+#else
+static struct esp_rtc_backup_s g_rtc_saved_data;
+#endif
 static struct esp_rtc_backup_s *g_rtc_save;
 
 /****************************************************************************
@@ -326,6 +332,7 @@ static int esp_rtc_rdtime(struct rtc_lowerhalf_s *lower,
   if (gmtime_r(&timer, (struct tm *)rtctime) == 0)
     {
       int errcode = get_errno();
+
       DEBUGASSERT(errcode > 0);
 
       rtcerr("gmtime_r failed: %d\n", errcode);
@@ -949,6 +956,7 @@ int esp_rtc_driverinit(void)
   struct rtc_lowerhalf_s *lower = (struct rtc_lowerhalf_s *)&g_rtc_lowerhalf;
 
   int ret = rtc_initialize(0, lower);
+
   if (ret < 0)
     {
       return ret;