Documentation: Update changelog.

[pub/lufa.git] / Projects / AVRISP-MKII / Lib / V2ProtocolParams.c

diff --git a/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c b/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c
index aaa988c..c42c6c4 100644 (file)
--- a/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c
+++ b/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c
@@ -1,13 +1,13 @@
 /*
              LUFA Library
 /*
              LUFA Library

-     Copyright (C) Dean Camera, 2016.
+     Copyright (C) Dean Camera, 2021.

 
   dean [at] fourwalledcubicle [dot] com
            www.lufa-lib.org
 */
 
 /*
 
   dean [at] fourwalledcubicle [dot] com
            www.lufa-lib.org
 */
 
 /*

-  Copyright 2016  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+  Copyright 2021  Dean Camera (dean [at] fourwalledcubicle [dot] com)

 
   Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted
 
   Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted


@@ -42,6 +42,14 @@ static uint8_t EEMEM EEPROM_Reset_Polarity = 0x01;
 /* Non-Volatile Parameter Values for EEPROM storage */
 static uint8_t EEMEM EEPROM_SCK_Duration   = 0x06;
 
 /* Non-Volatile Parameter Values for EEPROM storage */
 static uint8_t EEMEM EEPROM_SCK_Duration   = 0x06;
 

+/* Randomly generated magic constant for EEPROM data validation */
+#define EEPROM_MAGIC 0xEB401412UL
+
+/* EEPROM location which should contain EEPROM_MAGIC.  If this value is not correct, all other EEPROM locations are
+ * assumed to contain invalid data, therefore all parameters will be reset to their default values.
+ */
+static uint32_t EEMEM EEPROM_Magic_Value = EEPROM_MAGIC;
+

 /* Volatile Parameter Values for RAM storage */
 static ParameterItem_t ParameterTable[] =
        {
 /* Volatile Parameter Values for RAM storage */
 static ParameterItem_t ParameterTable[] =
        {


@@ -87,9 +95,29 @@ static ParameterItem_t ParameterTable[] =
        };
 
 
        };
 
 

+/** Check the non-volatile storage in the EEPROM for the proper magic value, and erase the parameter area if the magic
+ *  value was not correct.
+ */
+static void V2Params_CheckNonVolatileStorage(void)
+{
+       /* Read the magic value from the EEPROM */
+       uint32_t MagicValue = eeprom_read_dword(&EEPROM_Magic_Value);
+       if (MagicValue != EEPROM_MAGIC) {
+               /* If the magic value was not correct, erase the parameter values in the EEPROM */
+               eeprom_update_byte(&EEPROM_Reset_Polarity, 0xFF);
+               eeprom_update_byte(&EEPROM_SCK_Duration, 0xFF);
+
+               /* Write the correct magic value to confirm that the data stored in the EEPROM is now valid */
+               eeprom_update_dword(&EEPROM_Magic_Value, EEPROM_MAGIC);
+       }
+}
+

 /** Loads saved non-volatile parameter values from the EEPROM into the parameter table, as needed. */
 void V2Params_LoadNonVolatileParamValues(void)
 {
 /** Loads saved non-volatile parameter values from the EEPROM into the parameter table, as needed. */
 void V2Params_LoadNonVolatileParamValues(void)
 {

+       /* Check that the EEPROM contains valid data */
+       V2Params_CheckNonVolatileStorage();
+

        /* Read parameter values that are stored in non-volatile EEPROM */
        uint8_t ResetPolarity = eeprom_read_byte(&EEPROM_Reset_Polarity);
        uint8_t SCKDuration   = eeprom_read_byte(&EEPROM_SCK_Duration);
        /* Read parameter values that are stored in non-volatile EEPROM */
        uint8_t ResetPolarity = eeprom_read_byte(&EEPROM_Reset_Polarity);
        uint8_t SCKDuration   = eeprom_read_byte(&EEPROM_SCK_Duration);