/*
 * xmodem-at91.c
 *
 * A simple program using xmodem/1kxmode upload file to at91rm9200 based board.
 * Created by (C) Copyright 2004
 * Linhang.Zhang, Jilin University of PR.China, linxing@jlu.edu.cn.
 *
 * Modified 01-Feb-2005 (C)Copyright 2005 
 * Marco Cavallini, www.KoanSoftware.com - ITALY, m.cavallini@koansoftware.com
 * - edited indentations and changed break usage in switch statement.
 * - added "\r" to printf
 * 
 * Modified 13-Apr-2006 Marco Cavallini
 * - typo error (thank you Goran !)
 * 
 * Modified 7-jun-2012
 * - Adapted to work with the ArmadaXP-A0 Silicone
 * - replaced CRC with checksum
 * - discarded meanless characters in RX (printings done by BootROM).
 *
 * - build with 
 *   gcc sx-at91.c -o sx-at91
 *
 * - Howto use this program with minicom/xminicom and AT91 
 *   start minicom or xminicom
 *   edit Options / File transfer protocol, 
 *   add a name (for example J) like the following example
 *
 *   |     Name             Program                 Name U/D FullScr IO-Red. Multi  |
 *   | A  zmodem     /usr/bin/sz -vv -b              Y    U    N       Y       Y    |
 *   | B  ymodem     /usr/bin/sb -vv                 Y    U    N       Y       Y    |
 *   | C  xmodem     /usr/bin/sx -vv                 Y    U    N       Y       N    |
 *   | D  zmodem     /usr/bin/rz -vv -b -E           N    D    N       Y       Y    |
 *   | E  ymodem     /usr/bin/rb -vv                 N    D    N       Y       Y    |
 *   | F  xmodem     /usr/bin/rx -vv                 Y    D    N       Y       N    |
 *   | G  kermit     /usr/bin/kermit -i -l %l -s     Y    U    Y       N       N    |
 *   | H  kermit     /usr/bin/kermit -i -l %l -r     N    D    Y       N       N    |
 *   | I  ascii      /usr/bin/ascii-xfr -dsv         Y    U    N       Y       N    |
 *   | J  at91       /home/koan/xmodem/sx-at91       Y    U    Y       N       N    |
 *   | K    -                                                                       |
 *   | L    -                                                                       |
 *
 *   save and use it selecting at91 protocol when you start an Xmodem upload to AT91
 *
 *************************************************************************************
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include     <stdio.h>
#include     <stdlib.h>
#include     <unistd.h>
#include     <sys/types.h>
#include     <sys/stat.h>
#include     <fcntl.h>
#include     <termios.h>
#include     <errno.h>
#include     <time.h>

/*
Xmodem Frame form: <SOH><blk #><255-blk #><--128 data bytes--><CRC hi><CRC lo>
*/

#define XMODEM_SOH 0x01
#define XMODEM_STX 0x02
#define XMODEM_EOT 0x04
#define XMODEM_ACK 0x06
#define XMODEM_NAK 0x15
#define XMODEM_CRC_CHR	'C'
#define XMODEM_CHECKSUM_SIZE 1
#define XMODEM_CRC_SIZE 2			/* Crc_High Byte + Crc_Low Byte */
#define XMODEM_FRAME_ID_SIZE 2 /* Frame_Id + 255-Frame_Id */
#define XMODEM_DATA_SIZE_SOH 128  /* for Xmodem protocol */
#define XMODEM_DATA_SIZE_STX 1024 /* for 1K xmodem protocol */
#define USE_1K_XMODEM 0  /* 1 for use 1k_xmodem 0 for xmodem */

#if (USE_1K_XMODEM)
	#define XMODEM_DATA_SIZE 	XMODEM_DATA_SIZE_STX
	#define XMODEM_HEAD		XMODEM_STX
#else
	#define XMODEM_DATA_SIZE 	XMODEM_DATA_SIZE_SOH
	#define XMODEM_HEAD 		XMODEM_SOH
#endif
/*********/

#define SERIAL_DEVICE "/dev/ttyUSB0"
#define MYBAUDRATE B115200

/***************SUB PROGRAM*******/
unsigned short GetCrc16 ( char *ptr, unsigned short count )
{
	unsigned short crc, i;

	crc = 0;
	while(count--)
	{
		crc = crc ^ (int) *ptr++ << 8;
	
		for(i = 0; i < 8; i++)
		{
			if(crc & 0x8000)
				crc = crc << 1 ^ 0x1021;
			else			
				crc = crc << 1;
		}
	}

	return (crc & 0xFFFF);
}

/*******************************/
int Initial_SerialPort(char * serial_port)
{
	int fd;
	struct termios options;

	fd = open( serial_port, O_RDWR | O_NOCTTY | O_NDELAY );
	if ( fd == -1 )
	{ 
		/*open error!*/
		perror("Can't open serial port!");
		return -1;
	}

	/*Get the current options for the port...*/
	tcgetattr(fd, &options);

	/*Set the baud rates to BAUDRATE...*/
	cfsetispeed(&options,MYBAUDRATE);
	cfsetospeed(&options,MYBAUDRATE);
	tcsetattr(fd, TCSANOW, &options);
	if (0 != tcgetattr(fd, &options)) 
	{
		perror("SetupSerial 1");
		return -1;
	} 
	
	/*
	 * 8bit Data,no partity,1 stop bit...
	 */
	options.c_cflag &= ~PARENB;
	options.c_cflag &= ~CSTOPB;
	options.c_cflag &= ~CSIZE;
	options.c_cflag |= CS8;
	tcflush(fd,TCIFLUSH);

	/***Choosing Raw Input*/
	options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
	options.c_oflag &= ~OPOST; 

	/*
	 * Set the new options for the port...
	 */
	if (0 != tcsetattr(fd, TCSANOW, &options))
	{
 		perror("SetupSerial error");
 		return -1 ;
	}

	return fd ;
}

//******************************
void ClearReceiveBuffer(int fd)
{
	unsigned char tmp;
	while ((read(fd,&tmp,1))>0);
	
	return;
}

//********************************
int main(int argc,char *argv[])
{
	int fd;
	char *data_file_name;
	char packet_data[ XMODEM_DATA_SIZE ];
//	char frame_data[ XMODEM_DATA_SIZE + XMODEM_CRC_SIZE + XMODEM_FRAME_ID_SIZE + 1 ];
	char frame_data[ XMODEM_DATA_SIZE + XMODEM_CHECKSUM_SIZE + XMODEM_FRAME_ID_SIZE + 1 ];
	unsigned char tmp;
	FILE *datafile;
	int complete,retry_num,pack_counter,read_number,write_number,i;
	unsigned short crc_value;
	unsigned char ack_id;
        unsigned int checksum = 0;

	if (argc == 1) {
		printf("Usage %s <uart device> <file to transfer>\n", argv[0]);
		printf("     Example %s /dev/ttyS0 myfile.bin\n", argv[0]);
		return 0;
	}
		

	printf("Opening Uart %s... ", argv[1]);
	if ( (fd = Initial_SerialPort(argv[1])) == -1) {
		perror ("Failed!\n");
		return -1 ;
	}
	printf("Done\n");

	data_file_name = argv[2];

	if((datafile=fopen(data_file_name,"rb"))==NULL)
	{
		perror ("Can't open file!");
		return -1 ;
	}

	//*******************************
	
	pack_counter = 0;
	complete = 0;
	retry_num = 0;
	ClearReceiveBuffer(fd);

	while((read(fd,&ack_id,1))<=0);
	
	printf("%c\r\n",ack_id);
	ack_id=XMODEM_ACK;
	while(!complete)
	{

		switch(ack_id)
		{
		case XMODEM_ACK:
			retry_num = 0;
			checksum = 0;
			pack_counter++;
			read_number = fread( packet_data, sizeof(char), XMODEM_DATA_SIZE, datafile);
			if(read_number>0)
			{
				if(read_number<XMODEM_DATA_SIZE_SOH)
				{
			
					printf("Start filling the last frame!\r\n");
					for(;read_number<XMODEM_DATA_SIZE;read_number++)
						packet_data[read_number] = 0x00;
				}
				frame_data[0] = XMODEM_HEAD;
				frame_data[1] = (char)pack_counter;
				frame_data[2] = (char)(255-frame_data[1]);
	
				for(i=0;i<XMODEM_DATA_SIZE;i++) {
					frame_data[i+3]=packet_data[i];
					checksum+=packet_data[i];	
				}
				checksum = checksum%256;
//				crc_value = GetCrc16(packet_data,XMODEM_DATA_SIZE);
//				frame_data[XMODEM_DATA_SIZE_SOH+3]=(unsigned char)(crc_value >> 8);
				frame_data[XMODEM_DATA_SIZE_SOH+3]=(unsigned char)(checksum);
//				frame_data[XMODEM_DATA_SIZE_SOH+4]=(unsigned char)(crc_value);
//				write_number = write( fd, frame_data, XMODEM_DATA_SIZE_SOH + 5);
				write_number = write( fd, frame_data, XMODEM_DATA_SIZE_SOH + 4);
				printf("wait for ACK,%d,%d,...",pack_counter,write_number);
				while(1) {
					while((read(fd,&ack_id,1))<=0);			

					if(ack_id == XMODEM_ACK) {
						printf("Ok!       \r");
						break;
					}
					else if(ack_id == XMODEM_NAK) {
						printf("Error! NAK\r");
						break;
					}
					else
						printf("Skip!     \r");
				}
			}
			else
			{
				ack_id = XMODEM_EOT;
				complete = 1;
				printf("Waiting for complete ACK ...");
			
				while(ack_id != XMODEM_ACK)
				{
					ack_id = XMODEM_EOT;	
					write_number=write(fd,&ack_id,1);
					while((read(fd,&ack_id,1))<=0);
				}
				printf("OK\r");
		
				printf("Sending file complete\r\n");
			}
		break;

		case XMODEM_NAK:
			if( retry_num++ > 10) 
			{
				printf("Retry too many times,Quit!\r\n");
				complete = 1;
			}
			else
			{
//				write_number = write(fd,frame_data,XMODEM_DATA_SIZE + 5);
				write_number = write(fd,frame_data,XMODEM_DATA_SIZE + 4);
				printf("Retry for ACK,%d,%d...",pack_counter,write_number);
				while(1) {
					while((read(fd,&ack_id,1))<=0);			

					if(ack_id == XMODEM_ACK) {
						printf("Ok!       \r");
						break;
					}
					else if(ack_id == XMODEM_NAK) {
						printf("Error! NAK\r");
						break;
					}
					else
						printf("Skip!     \r");
				}
			}
		break;

		default:
			printf("Fatal Error!\r\n");
			complete = 1;
		break;
		}

	}

	fclose(datafile);
	close(fd);

	return 0;
}