/*-------------------------------------------------------------------------/
/  Stand-alone MMC boot loader  R0.01
/--------------------------------------------------------------------------/
/
/  Copyright (C) 2010, ChaN, all right reserved.
/
/ * This software is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/--------------------------------------------------------------------------/
/ Dec 6, 2010  R0.01  First release
/--------------------------------------------------------------------------/
/ This is a stand-alone MMC/SD boot loader for megaAVRs. It requires a 4KB
/ boot section for code, four GPIO pins for MMC/SD as shown in sch.jpg and
/ nothing else. To port the boot loader into your project, follow the
/ instruction sdescribed below.
/
/ 1. Setup the hardware. Attach a memory card socket to the any GPIO port
/    where you like. Select boot size at least 4KB for the boot loader with
/    BOOTSZ fuses and enable boot loader with BOOTRST fuse.
/
/ 2. Setup the software. Change the four port definitions in the asmfunc.S.
/    Change MCU_TARGET, BOOT_ADR and MCU_FREQ in the Makefile. The BOOT_ADR
/    is a BYTE address of boot section in the flash. Build the boot loader
/    and write it to the device with a programmer.
/
/ 3. Build the application program and output it in binary form instead of
/    hex format. Rename the file "app.bin" and put it into the memory card.
/
/ 4. Insert the card and turn the target power on. When the boot loader found
/    the application file, the file is written into the flash memory prior to
/    start the application program. On-board LED lights (if exist) during
/    the flash programming operation.
/
/--------------------------------------------------------------------------/
/ Modified by Steve Chamberlin for Floppy Emu, October 2013
/-------------------------------------------------------------------------*/


#include <avr/io.h>
#include <avr/pgmspace.h>
#include <util/delay.h>
#include <string.h>
#include "pff.h"
#include "lcd.h"

void flash_erase (DWORD);				/* Erase a flash page (asmfunc.S) */
void flash_write (DWORD, const BYTE*);	/* Program a flash page (asmfunc.S) */

FATFS Fatfs;				/* Petit-FatFs work area */
BYTE Buff[SPM_PAGESIZE];	/* Page data buffer */

#define BUTTON_PORT PORTD
#define BUTTON_PIN PIND
#define SELECT_BUTTON_PIN 4
#define PREV_BUTTON_PIN 1
#define NEXT_BUTTON_PIN 2

#define LED_DDR DDRB
#define LED_PORT PORTB
#define LED_PIN_NUMBER 3

int main (void)
{
	DWORD fa;	/* Flash address */
	WORD br;	/* Bytes read */

	// enable the pull-up resistor for the user buttons
	BUTTON_PORT |= (1<<SELECT_BUTTON_PIN);
	BUTTON_PORT |= (1<<PREV_BUTTON_PIN);
	BUTTON_PORT |= (1<<NEXT_BUTTON_PIN);
	
	_delay_ms(10);
	
	// if PREV and SELECT are pressed, try to perform an application update
	if (bit_is_clear(BUTTON_PIN, PREV_BUTTON_PIN) &&
		bit_is_clear(BUTTON_PIN, SELECT_BUTTON_PIN))
	{		
		// set LED as output
		LED_DDR |= (1<<LED_PIN_NUMBER);
	
		LcdInit();
		LcdString(PSTR("FLOPPYXEMUXBOOTLOADER"));
		LcdGoto(0,2);
		
		pf_mount(&Fatfs);	/* Initialize file system */
		if (pf_open("femu.bin") == FR_OK) /* Open application file */
		{			
			LcdString(PSTR("FLASHINGXFEMUQBINXQQQ"));
			
			for (fa = 0; fa < BOOT_ADR; fa += SPM_PAGESIZE) /* Update all application pages */
			{			
				flash_erase(fa);					/* Erase a page */
				memset(Buff, 0xFF, SPM_PAGESIZE);	/* Clear buffer */
				pf_read(Buff, SPM_PAGESIZE, &br);	/* Load a page data */
				if (br) flash_write(fa, Buff);		/* Write it if the data is available */
				
				// blink the LED while writing
				LED_PORT ^= (1<<LED_PIN_NUMBER);
			}
		}
		else	
		{
			// couldn't open the application file
			LcdString(PSTR("FEMUQBINXNOTXFOUND"));
		}
		
		// wait for all buttons to be released
		while (bit_is_clear(BUTTON_PIN, PREV_BUTTON_PIN) ||
			   bit_is_clear(BUTTON_PIN, SELECT_BUTTON_PIN) ||
			   bit_is_clear(BUTTON_PIN, NEXT_BUTTON_PIN))
		{}		
	}
		
	if (pgm_read_word(0) != 0xFFFF)		/* Start application if exist */
		((void(*)(void))0)();

	/* No application, Halt. */
	LcdInit();
	LcdGoto(0,0);
	LcdString(PSTR("ERRORZXFLASHXISXEMPTY"));
	for (;;) ;	
}