Open source PBP bootloader

[cncmachineguy]

Made a little more progress, also fixed some thing in what I already had. Any questions, comments, or suggestions ask away!

' *****************************************************************************
'        Software License Agreement				    
'		 						    
' The software supplied herewith by PBP forum members 	    
' (the “Company”) for Microchip's PICmicro® Microcontroller's is 
' intended and supplied to you, the Company’s customer, for use     
' solely and exclusively on Microchip PICmicro Microcontroller	    
' products. The software is owned by the Company and/or its         
' supplier, and is protected under applicable copyright laws. All   
' rights are reserved. Any use in violation of the foregoing 	     
' restrictions may subject the user to criminal sanctions under	    
' applicable laws, as well as to civil liability for the breach of  
' the terms and conditions of this license.			    
'								    
' THIS SOFTWARE IS PROVIDED IN AN “AS IS” CONDITION. NO WARRANTIES, 
' WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED 
' TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 	    
' PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE COMPANY SHALL NOT, 
' IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR 	    
' CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.		    
'								    
'					 			    
' This software has been ported from Microchip's AN851 bootloader
' Changes have been made and will be made as the company sees fit.
' This version is for 16F's, there is another version for 18F's
'
'
' Memory Map
'	-----------------
'	|    0x0000	|	Reset vector
'	|        	|
'                |   0x0004	|	Interrupt vector
'	|    	|	
'	|	    |
'	|Boot Block |	(this program)
' 	|		    |
'	|    0x0200	|	Re-mapped Reset Vector
'	|    0x0204	|	Re-mapped High Priority Interrupt Vector
'	|		    |
'	|   	    |	
'	|		    |
'               |Code Space |	User program space
'	|		    |
'	|		    |
'	|		    |
'	|    0x3FFF |
'	-----------------
'
' Incomming data format:
'
'   {STX}{STX}{DATA}{CHKSUM}{ETX}
'	      /    \
'	 ________/      \__________________________
'	/	                                         \
'	{COMMAND}{DLEN}{ADDRL}{ADDRH}{ADDRU}{DATA}...
'
' Definitions:
'
' 	STX  	-	Start of packet indicator
'	ETX 	-	End of packet indicator
' 	LEN 	-	Length of incomming packet
' 	DATA	-	General data up to 255 bytes
' 	CHKSUM 	- 	The 8-bit two's compliment sum of LEN & DATA
' 	COMMAND - 	Base command
' 	DLEN	-	Length of data associated to the command
' 	ADDR	-	Address up to 24 bits
' 	DATA 	-	Data (if any)
'
'
' Commands:
'
' 	RD_VER		00	Read Version Information
' 	RD_MEM		01	Read Program Memory
' 	WR_MEM		02	Write Program Memory
' 	ER_MEM		03	Erase Program Memory (NOT supported by PIC16)
' 	RD_EE		04	Read EEDATA Memory 
' 	WR_EE		05	Write EEDATA Memory 
' 	RD_CONFIG	06	Read Config Memory (NOT supported by PIC16)
' 	WT_CONFIG	07	Write Config Memory (NOT supported by PIC16)
'
' ****************************************************************************

' *****************************************************************************
CHKSUM		VAR	BYTE		' Checksum accumulator
COUNTER		VAR	BYTE		' General counter
ABTIME		VAR	BYTE
RXDATA		VAR	BYTE
TXDATA		VAR	BYTE
TEMP		VAR	BYTE
ARRAYPOINTER VAR BYTE

TEMPFLAG    VAR BIT

PCLATH_TEMP	VAR	BYTE		' Interrupt context
STATUS_TEMP	VAR	BYTE		' save/restore registers
W_TEMP		VAR	BYTE

' Frame Format
'
'  {STX}{STX}[{COMMAND}{DATALEN}{ADDRL}{ADDRH}{ADDRU}{...DATA...}]{CHKSUM}{ETX}

DATA_BUFF	VAR	BYTE[50]		' Start of receive buffer SAME ADDRESS AS COMMAND
	
COMMAND		VAR	DATA_BUFF[0]		' Data mapped in receive buffer SAME ADDRESS AS DATA_BYTE
DATA_COUNT	VAR	DATA_BUFF[1]
ADDRESS_L	VAR	DATA_BUFF[2]
ADDRESS_H	VAR	DATA_BUFF[3]
ADDRESS_U	VAR	DATA_BUFF[4]
  'PACKET_DATA	VAR	DATA_BUFF[5-49]	'Maybe we don't need this line?**************
' *****************************************************************************


'  This is the remapping section, note the interrupt also saves context
' *****************************************************************************
@	ORG	0x0000			' Re-map Reset vector **Not sure how to set the address to start at
VReset:
	PCLATH = 0
	goto	Setup								

@	ORG	0x0004			'standard interrupt vector **again not sure of the PBP equal for ORG
VInt:
	W_TEMP = W			   'I am assuming this will be the "W" register			
	STATUS_TEMP = STATUS   'We may have trouble here. ASM uses SWAP so as not to affect the status
	STATUS = 0
	PCLATH_TEMP = PCLATH
	PCLATH = 0
	goto	RVInt	    ' Re-map Interrupt vector		

' *****************************************************************************
 *****************************************************************************
' Setup the appropriate registers.
Setup:
	clrwdt
	READ $ff,temp		         'get the value of last EEPROM location
	IF temp = $ff then goto SRX  'BL startup
	goto	RVReset			     ' If not 0xFF then normal reset	

SRX:
	RCSTA = %10000000		' Setup rx and tx, CREN disabled
	TRISC.6 = 0 			' Setup tx pin		
	TXSTA = %00100110			
	STATUS.IRP = 1
' *****************************************************************************


' *****************************************************************************
Autobaud:
'
' ___	 __________            ________
'    \__/	       \__________/
'       |                     |
'       |-------- p ----------|
'
'	p = The number of instructions between the first and last
'           rising edge of the RS232 control sequence 0x0F. Other 
'	    possible control sequences are 0x01, 0x03, 0x07, 0x1F, 
' 	    0x3F, 0x7F.
'
'	SPBRG = (p / 32) - 1  	BRGH = 1
										

	OPTION_REG = %00000011	'sets tmr0 to 1:16 prescale
	STATUS.RP0	= 0						
	RCSTA.CREN = 0							

	gosub	WaitForRise							
	 
	TMR0 = 0		     ' Start counting			

	gosub	WaitForRise							

	ABTIME = TMR0		 ' Read the timer		
	TEMPFLAG = ABTIME.0
	ABTIME = ABTIME >>1							
	IF !TEMPFLAG THEN ABTIME.0 = 0 'Rounding	
	SPBRG = ABTIME
	RCSTA.CREN = 1		 ' Enable receive	

	TEMP = RCREG		' To clear the Rx buffer					
	TEMP = RCREG		' Both of them						
						
	OPTION_REG = %11111111 'Return Option Reg to reset state							
							
' *****************************************************************************


' *****************************************************************************
' Read and parse the data.
StartOfLine:						
	GOSUB	RdRS232			' Look for a start of line	
	IF RXDATA != STX THEN Autobaud	    '{STX}{STX}				
                 		
                ARRAYPOINTER = 0		' Point to the beginning of Array						

	CHKSUM	= 0     		' Reset checksum		
		
GetNextDat:			
	GOSUB	RdRS232			' Get the data			
	IF RXDATA = STX	THEN StartOfLine    ' Check for a STX			
	                		' Yes, start over			

NoSTX:
	IF RXDATA = ETX  THEN CheckSum    ' Check for a ETX			
								' Yes, examine checksum		

NoETX:
	IF RXDATA = DLE THEN GOSUB RdRS232 ' Check for a DLE
	                                   ' Yes, Get the next byte	
	
NoDLE:
	DATA_BUFF[ARRAYPOINTER] = RXDATA   ' Store the data		
	CHKSUM = CHKSUM + RXDATA           ' Get sum				
	ARRAYPOINTER = ARRAYPOINTER + 1								

	goto	GetNextDat						

CheckSum:
	IF CHKSUM = 0 THEN Autobaud  ' Checksum test					
' ***********************************************

[cncmachineguy]

Just wanted to say, I am sorry this is taking me so long to convert. It is a simple matter to just change the ASM to PBP, but I am making sure I understand everything as I convert. That way when it doesn't work, I can at least have half a chance to find the problem. Also this will make it easier when we try to start making this do different things like I2C, or have it pass the program to another uP.