From 89b3251dde98d408db14ddbcc7c7063d4a50315b Mon Sep 17 00:00:00 2001
From: Jason Lefley <jlefley@gmail.com>
Date: Wed, 18 Mar 2015 15:28:12 -0700
Subject: [PATCH] add support for atmega328p

---
 Makefile |  8 ++++++++
 main.c   | 19 ++++++++++++++-----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index e8437df..4eb04cb 100644
--- a/Makefile
+++ b/Makefile
@@ -39,6 +39,14 @@ AVRDUDE_FUSES=lfuse:w:0xc2:m hfuse:w:0xdd:m efuse:w:0xfa:m
 BOOTLOADER_START=0x3C00
 endif
 
+ifeq ($(MCU), atmega328p)
+# (8Mhz internal RC-Osz., 2.7V BOD)
+AVRDUDE_MCU=m328p -F
+AVRDUDE_FUSES=lfuse:w:0xc2:m hfuse:w:0xda:m efuse:w:0xfd:m
+
+BOOTLOADER_START=0x7800
+endif
+
 # ---------------------------------------------------------------------------
 
 CFLAGS = -pipe -g -Os -mmcu=$(MCU) -Wall -fdata-sections -ffunction-sections
diff --git a/main.c b/main.c
index e1d36dc..c70e489 100644
--- a/main.c
+++ b/main.c
@@ -35,6 +35,11 @@
  * Fuse E: 0xfa (512 words bootloader)
  * Fuse H: 0xdd (2.7V BOD)
  * Fuse L: 0xc2 (8Mhz internal RC-Osz.)
+ *
+ * atmega328p:
+ * Fuse E: 0xfd (2.7V BOD)
+ * Fuse H: 0xda (1024 words bootloader)
+ * Fuse L: 0xc2 (8Mhz internal RC-Osz.)
  */
 
 #if defined (__AVR_ATmega8__)
@@ -49,6 +54,10 @@
 #define VERSION_STRING		"TWIBOOT m168v2.1"
 #define SIGNATURE_BYTES		0x1E, 0x94, 0x06
 
+#elif defined (__AVR_ATmega328P__)
+#define VERSION_STRING		"TWIBOOT m328pv2.1"
+#define SIGNATURE_BYTES		0x1E, 0x95, 0x0F
+
 #else
 #error MCU not supported
 #endif
@@ -145,7 +154,7 @@
  *   SLA+W, 0x02, 0x02, addrh, addrl, {* bytes}, STO
  */
 
-const static uint8_t info[16] = VERSION_STRING;
+const static uint8_t info[18] = VERSION_STRING;
 const static uint8_t chipinfo[8] = {
 	SIGNATURE_BYTES,
 
@@ -214,7 +223,7 @@ static void write_eeprom_byte(uint8_t val)
 #if defined (__AVR_ATmega8__)
 	EECR |= (1<<EEMWE);
 	EECR |= (1<<EEWE);
-#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__)
+#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__) || defined (__AVR_ATmega328P__)
 	EECR |= (1<<EEMPE);
 	EECR |= (1<<EEPE);
 #endif
@@ -403,7 +412,7 @@ static void (*jump_to_app)(void) __attribute__ ((noreturn)) = 0x0000;
  * system reset. So disable it as soon as possible.
  * automagically called on startup
  */
-#if defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__)
+#if defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__) || defined (__AVR_ATmega328P__)
 void disable_wdt_timer(void) __attribute__((naked, section(".init3")));
 void disable_wdt_timer(void)
 {
@@ -427,7 +436,7 @@ int main(void)
 
 	TCCR0 = (1<<CS02) | (1<<CS00);
 	TIMSK = (1<<TOIE0);
-#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__)
+#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__) || defined (__AVR_ATmega328P__)
 	MCUCR = (1<<IVCE);
 	MCUCR = (1<<IVSEL);
 
@@ -454,7 +463,7 @@ int main(void)
 
 	GICR = (1<<IVCE);
 	GICR = (0<<IVSEL);
-#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__)
+#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__) || defined (__AVR_ATmega328P__)
 	TIMSK0 = 0x00;
 	TCCR0B = 0x00;