From cbab11f918a39dc1ead7b8150930a12a2302b02a Mon Sep 17 00:00:00 2001
From: lulko <keklolov7@gmail.com>
Date: Mon, 14 Apr 2025 17:31:11 +0300
Subject: [PATCH] Add chech CRC-16

---
 src/flash.cpp | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/flash.cpp b/src/flash.cpp
index 381c092..fed53e4 100644
--- a/src/flash.cpp
+++ b/src/flash.cpp
@@ -116,11 +116,21 @@ uint8_t flash_read_word(uint32_t address){
 }
     // Wait if flash
 
-
-bool validate_crc(FLASH_RECORD* crc){
-    if(crc->crc == 6933)
-        return true;
-    return false;
+bool validate_crc(FLASH_RECORD* ptr, uint32_t length) {
+    uint16_t crc = 0xFFFF; // Начальное значение
+    uint16_t crc_value = ptr->crc;
+    uint8_t* data = reinterpret_cast<uint8_t*>(&crc_value);
+    while (length--) {
+        crc ^= *data++; // Обрабатываем LSB первым
+        for (uint8_t i = 0; i < 8; i++) {
+            if (crc & 0x0001) { // Проверяем младший бит
+                crc = (crc >> 1) ^ 0xA001; // Полином 0x8005 (reverse)
+            } else {
+                crc >>= 1;
+            }
+        }
+    }
+    return crc == 0? true : false;
 }
 /*      read struct from FLASH      */
 void flash_read(uint32_t addr,FLASH_RECORD* ptr){
@@ -136,7 +146,7 @@ void compact_page(){
         FLASH_RECORD rec;
         flash_read(i,&rec);
 
-        if (validate_crc(&rec)){
+        if (validate_crc(&rec,2)){
             latest[rec.data_id] = rec;
         }
     }
@@ -186,7 +196,7 @@ FLASH_RECORD* load_params(){
     FLASH_RECORD res;
     for(uint32_t addr = SECTOR_6;addr < SECTOR_6_END;addr +=FLASH_RECORD_SIZE) {
         flash_read(addr,&res);
-        if (!validate_crc(&res))
+        if (!validate_crc(&res,2))
             break;
         else{
             latest[res.data_id] = res;