feat(compatibility_upgrade): add function to get old SDK's target ap SSID and passowrd

Add error warning to check the wrong parition table.

components/esp8266/include/internal/esp_system_internal.h

@@ -23,11 +23,33 @@ extern "C" {
 
 #define RTC_SYS_RAM_SIZE            256
 
+/**
+ * @brief Station's AP base information of old SDK
+ */
+struct old_ap_ssid {
+    uint32_t                    len;                    //!< SSID length
+    uint8_t                     ssid[32];               //!< SSID data
+    uint8_t                     passwd[64];             //!< password data
+} __attribute__((packed));
+
+/**
+ * @brief System information of old SDK
+ */
+struct old_sysconf {
+    uint8_t                     reserved_1[0x13C];      //!< reserved data
+    uint8_t                     ap_number;              //!< number of stored AP
+    uint8_t                     ap_index;               //!< index of current used AP
+    uint8_t                     reserved_2[0x2];        //!< reserved data
+    struct old_ap_ssid          ap_ssid[5];             //!< station's AP base information
+} __attribute__((packed));
+
 /**
  * The size of structure must not be larger than 256 bytes and all member varible must be uint32_t type
  */
 struct _rtc_sys_info {
     uint32_t        hint;   // software reset reason
+    uint32_t        old_sysconf_addr;   /*<! old SDK system configuration parameters base address, 
+                                             if your bootloader is older than v3.2, please don't use this */
 };
 
 extern struct _rtc_sys_info rtc_sys_info;
@@ -56,6 +78,13 @@ void esp_reset_reason_set_hint(esp_reset_reason_t hint);
  */
 esp_reset_reason_t esp_reset_reason_early(void);
 
+/**
+ * @brief Get old SDK configuration parameters base address
+ *
+ * @return 0 if it is not upgraded from old SDK or the absolute address of the flash 
+ */
+uint32_t esp_get_old_sysconf_addr(void);
+
 #ifdef __cplusplus
 }
 #endif

components/esp8266/source/reset_reason.c

@@ -41,12 +41,8 @@ static inline void esp_reset_reason_clear_hint()
 
 static inline uint32_t esp_reset_reason_get_hint(uint32_t hw_reset)
 {
-    if (hw_reset == POWERON_RESET && rtc_sys_info.hint != ESP_RST_SW) {
-        uint32_t *p = (uint32_t *)&rtc_sys_info;
-
-        for (int i = 0; i < RTC_SYS_RAM_SIZE / sizeof(uint32_t); i++)
-            *p++ = 0;
-    }
+    if (hw_reset == POWERON_RESET && rtc_sys_info.hint != ESP_RST_SW)
+        rtc_sys_info.hint = 0;
 
     return rtc_sys_info.hint;
 }

components/esp8266/source/system_api.c

@@ -17,6 +17,7 @@
 
 #include "esp_log.h"
 #include "esp_system.h"
+#include "internal/esp_system_internal.h"
 
 #include "crc.h"
 
@@ -352,3 +353,11 @@ uint32_t esp_get_minimum_free_heap_size(void)
 {
     return heap_caps_get_minimum_free_size(MALLOC_CAP_32BIT);
 }
+
+/**
+ * @brief Get old SDK configuration parameters base address
+ */
+uint32_t esp_get_old_sysconf_addr(void)
+{
+    return rtc_sys_info.old_sysconf_addr;
+}