;****************************************************************************** ; Bootloader for Microchip PIC16F870/871/873/874/876/877 * ; (c) 2000-2002, Petr Kolomaznik * ; Freely distributable * ;****************************************************************************** ; * ; Name of file: bootldr.asm * ; Date: 29th Dec 2002 * ; Version: 2.6 * ; * ; Author: Petr Kolomaznik * ; Company: EHL elektronika, Czech Republic * ; Email: kolomaznik@ehl.cz * ; Url: www.ehl.cz/pic * ; Modified by: Shane Tolmie (v2.30) * ; Company: DesignREM * ; Email: shane@microchipc.com * ; Url: www.microchipc.com * ; * ;****************************************************************************** ; How to use this bootloader: * ; - open project bootldr.pjt in MPLAB * ; - check and modify of parameters in the user setting section with <<< mark * ; - make project with MPLAB and MPASM * ; - use any programmer for programming of bootldr.hex to microcontroller * ; - set configuration bits * ; - use PIC downloader program for user program download * ; - check if user program doesn't use the top 214 program memory locations * ; * ; Notes: * ; - tab size for editor is 2 * ; - bootloader is compatible with HI-TECH's and Shane Tolmie's bootl./downl. * ;****************************************************************************** ; 2.60 - 29.12.2002 (Shane Tolmie [shane@microchipc.com]) * ; - made it so that frequencies <=4Mhz have XT, and freq >4Mhz have HS * ; configuration in the fuse bits, to enable it to work at all freq with * ; resonators. * ; 2.50 - 28.8.2002 (Shane Tolmie [shane@microchipc.com]) * ; - switched off BODEN which resets part if low voltage power supply used * ; (many grateful thanks to Richard (joshanks@earthlink.net) * ; 2.50 - 28.8.2002 (Shane Tolmie [shane@microchipc.com]) * ; - switched off BODEN which resets part if low voltage power supply used * ; (many grateful thanks to Richard (joshanks@earthlink.net) * ; 2.20 - 8.8.2001 (Shane Tolmie [shane@microchipc.com]) * ; - added watchdog user change, defaults to off (leaving it on can create * ; difficult to track down problems) * ; 2.10 - 3.8.2001 (jvo@vinylium.ch) * ; - substantially reduced size of program * ; - restores USART to reset condition before starting user program * ; - made user program start variable * ; - added trap to avoid unintended running into bootloader * ; - watchdog timeout is directly handled over to user program * ; 2.00 - 30.03.2001 (Shane Tolmie [shane@microchipc.com]) * ; - for the 16F876, the 4 instructions in the original .hex file at 0x0000 * ; to 0x0003 are copied to 0x1F00 to 0x1F03, and executed once the * ; bootloader is finished, to jump back to user code. The reset vector in * ; the chip at 0x0000 to 0x0003 points to the bootloader. Inserted a * ; pagesel 0x0000 (2 instructions) at 0x1F00 to make a short jump into a * ; long jump so it would work with .hex files that didnt have a long jump * ; as the first 4 instructions in the .hex file. * ; This addition dramatically increases compatibility with .hex files. * ; 1.06 - 30.03.2001 (Shane Tolmie) * ; - added config bits * ; - program now jumps immediately to user program after download * ; 1.02 - 15.11.2000 * ; - added check of user constants * ; - added support for the new 16F870/1/2 * ; - added errorlevel directive for message 302 and 306 * ;****************************************************************************** errorlevel -302, -306 ; no message 302 and 306 list b=2 ; tabulator size = 2 ;================== User setting section ====================================== list p=16f876 ; <<< set type of microcontroller ; set same microcontroller in the project #define ICD_DEBUG 0 ; <<< if using MPLAB ICD Debugger, moves bootloader down 256 bytes to make room for it [0|1] #define FOSC D'6000000' ; <<< set quartz frequence [Hz], max. 20 MHz #define BAUD D'19200' ; <<< set baud rate [bit/sec] #define BAUD_ERROR D'4' ; <<< set baud rate error [%] #define TIME ; <<< set method of bootloader start PIN/TIME ; PIN : start on low level of trigger pin ; TIME: start on receive IDENT byte in TIMEOUT #define TRIGGER PORTB,7 ; <<< only for PIN - set PORT_X,PIN_NR #define TIMEOUT D'2' ; <<< only for TIME - set time [0.1s], max. 25 sec #define WATCHDOGTIMER 0 ; <<< Watchdog timer default OFF/ON [0|1] ;=================== Configuration ============================================ __IDLOCS H'2100' ; version ID of bootloader IF WATCHDOGTIMER == 0 #define MY_WDT _WDT_OFF ELSE #define MY_WDT _WDT_ON ENDIF ;note: for high voltage parts, you can set BODEN_ON, but for low voltage parts it resets the circuit continuously! IF FOSC<=D'4000000' #define _MYCRYSTAL _XT_OSC ;see datasheet ELSE #define _MYCRYSTAL _HS_OSC ENDIF __CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_ON & _MYCRYSTAL & _WRT_ENABLE_ON & _LVP_OFF & _DEBUG_OFF & _CPD_OFF ;=============== End of user setting section ================================== ;================== Check User Constants ====================================== IFNDEF FOSC ERROR "FOSC must be defined" ENDIF IFNDEF BAUD ERROR "BAUD must be defined" ENDIF IF FOSC > D'20000000' ERROR "max. quartz frequency = 20 MHz" ENDIF IFNDEF PIN IFNDEF TIME ERROR "wrong start method of bootloader, must be PIN or TIME" ENDIF ENDIF IF TIMEOUT > D'254' ERROR "max. timeout = 25.4 sec" ENDIF IF ICD_DEBUG != 0 IF ICD_DEBUG != 1 ERROR "ICD debug must be 1 (enabled) or 0 (not used)" ENDIF ENDIF ;========================== Constants ========================================= IF ((FOSC/(D'16' * BAUD))-1) < D'256' #define DIVIDER (FOSC/(D'16' * BAUD))-1 #define HIGH_SPEED 1 ELSE #define DIVIDER (FOSC/(D'64' * BAUD))-1 #define HIGH_SPEED 0 ENDIF BAUD_REAL EQU FOSC/((D'64'-(HIGH_SPEED*D'48'))*(DIVIDER+1)) IF BAUD_REAL > BAUD IF (((BAUD_REAL - BAUD)*D'100')/BAUD) > BAUD_ERROR ERROR "wrong baud rate" ENDIF ELSE IF (((BAUD - BAUD_REAL)*D'100')/BAUD) > BAUD_ERROR ERROR "wrong baud rate" ENDIF ENDIF IF FOSC > D'10240000' #define T1PS 8 #define T1SU 0x31 ELSE IF FOSC > D'5120000' #define T1PS 4 #define T1SU 0x21 ELSE IF FOSC > D'2560000' #define T1PS 2 #define T1SU 0x11 ELSE #define T1PS 1 #define T1SU 0x01 ENDIF ENDIF ENDIF TIMER EQU (D'65538'-(FOSC/(D'10'*4*T1PS))); reload value for TIMER1 (0.1s int) IFDEF __16F877 #include #define ProgHI 0x1FFF ELSE IFDEF __16F876 #include #define ProgHI 0x1FFF ELSE IFDEF __16F874 #include #define ProgHI 0x0FFF ELSE IFDEF __16F873 #include #define ProgHI 0x0FFF ELSE IFDEF __16F872 #include #define ProgHI 0x07FF ELSE IFDEF __16F871 #include #define ProgHI 0x07FF ELSE IFDEF __16F870 #include #define ProgHI 0x07FF ELSE ERROR "incorrect type of microcontroller" ENDIF ENDIF ENDIF ENDIF ENDIF ENDIF ENDIF #define LoaderSize 0xD6 ; size of bootloader ;#define LoaderSize 0xD8 ; size of bootloader #define LoaderMain UserStart+5 ; main address of bootloader #define LoaderTop ProgHI-(ICD_DEBUG*0x100); top address of bootloader #define LoaderStart (LoaderTop)-LoaderSize+1; start address of bootloader #define NumRetries 1 ; number of writing retries #define WRITE 0xE3 ; communication protocol #define WR_OK 0xE4 #define WR_BAD 0xE5 #define DATA_OK 0xE7 #define DATA_BAD 0xE8 #define IDENT 0xEA #define IDACK 0xEB #define DONE 0xED ;=============== Variables ==================================================== buff EQU 0x20 ; RAM address 0x70 reserved for MPLAB-ICD amount EQU 0x71 chk1 EQU 0x72 chk2 EQU 0x73 retry EQU 0x74 address EQU 0x75 tmpaddr EQU 0x77 temp EQU 0x79 time EQU 0x7A count EQU 0x7B ;------------------------------------------------------------------------------ ORG 0x0000 ; reset vector of microcontroller nop ; for compatibility with ICD pagesel Main goto Main ;------------------------------------------------------------------------------ ORG LoaderStart TrapError pagesel TrapError goto TrapError ; trap for unintended running into Bootloader UserStart ; this instruction never gets overwritten clrf PCLATH ; set PCLATH to program page 0 ; the following 4 instructions get overwritten by user program pagesel UserStart ; set PCLATH to program page of UserStart goto UserStart ; loop for first start without a user program ;------------------------------------------------------------------------------ ORG LoaderMain Main btfss STATUS,NOT_TO ; run user program after WatchDog-TimeOut goto UserStart start movlw 0x90 ; SPEN = 1, CREN = 1 movwf RCSTA bsf STATUS,RP0 ; bank1 ; bcf TRISB,7 ; //jc - PIN_B7 as output IF HIGH_SPEED == 1 ; USART SYNC=0; SPEN=1; CREN=1; SREN=0; bsf TXSTA,BRGH ; TX9=0; RX9=0; TXEN=1; ELSE bcf TXSTA,BRGH ENDIF bsf TXSTA,TXEN movlw DIVIDER ; baud rate generator movwf SPBRG IFDEF PIN bsf TRIGGER ; for PIN: setting of TRIS for selected pin bcf STATUS,RP0 btfss TRIGGER goto receive ; go to bootloader goto user_restore ; run user program ELSE bcf STATUS,RP0 ; bank0 ; bsf PORTB,7 ; //jc - set PIN_B7 movlw TIMEOUT+1 ; for TIME: set timeout movwf time movlw T1SU movwf T1CON ; TIMER1 on, internal clock, prescale T1PS bsf PIR1,TMR1IF call getbyte ; wait for IDENT xorlw IDENT btfss STATUS,Z goto user_restore clrf time ; no more wait for IDENT goto inst_ident ; bootloader identified, send of IDACK ENDIF ;------------------------------------------------------------------------------ receive ; programming call getbyte ; get byte from USART movwf temp xorlw WRITE btfsc STATUS,Z goto inst_write ; write instruction movf temp,w xorlw IDENT btfsc STATUS,Z goto inst_ident ; identification instruction movf temp,w xorlw DONE btfss STATUS,Z ; done instruction ? goto receive ;------------------------------------------------------------------------------ inst_done ; very end of programming ;------------------------------------------------------------------------------ movlw WR_OK call putbyte ; send of byte movlw TIMEOUT+1 movwf time call getbyte ; has built in timeout - waits until done ;------------------------------------------------------------------------------ user_restore clrf T1CON ; shuts off TIMER1 clrf RCSTA bsf STATUS,RP0 clrf TXSTA ; restores USART to reset condition bcf STATUS,RP0 clrf PIR1 goto UserStart ; run user program ;------------------------------------------------------------------------------ inst_ident movlw IDACK ; send IDACK goto send_byte ;------------------------------------------------------------------------------ inst_write call getbyte movwf address+1 ; high byte of address call getbyte movwf address ; low byte of address call getbyte movwf amount ; number of bytes -> amount -> count movwf count call getbyte ; checksum -> chk2 movwf chk2 clrf chk1 ; chk1 = 0 movlw buff movwf FSR ; FSR pointer = buff receive_data call getbyte ; receive next byte -> buff[FSR] movwf INDF addwf chk1,f ; chk1 := chk1 + buff[FSR] incf FSR,f ; FSR++ decfsz count,f goto receive_data ; repeat until (--count==0) checksum movf chk1,w xorwf chk2,w ; if (chk1 != chk2) movlw DATA_BAD btfss STATUS,Z goto send_byte ; checksum WRONG checksum_ok movlw DATA_OK ; checksum OK call putbyte write_byte call write_eeprom ; write to eeprom iorlw 0 movlw WR_OK ; writing OK btfsc STATUS,Z movlw WR_BAD ; writing WRONG ;------------------------------------------------------------------------------ send_byte call putbyte ; send of byte goto receive ; go to receive from UART ;------------------------------------------------------------------------------ ;************************* putbyte subroutine ********************************* putbyte clrwdt btfss PIR1,TXIF ; while(!TXIF) goto putbyte movwf TXREG ; TXREG = byte return ;************************* getbyte subroutine ********************************* getbyte clrwdt IFNDEF PIN ; for TIME movf time,w btfsc STATUS,Z ; check for time==0 goto getbyte3 btfss PIR1,TMR1IF ; check for TIMER1 overflow goto getbyte3 ; no overflow bcf T1CON,TMR1ON ; timeout 0.1 sec decfsz time,f ; time-- goto getbyte2 retlw 0 ; if time==0 then return getbyte2 bcf PIR1,TMR1IF movlw high TIMER movwf TMR1H ; preset TIMER1 for 0.1s timeout bsf T1CON,TMR1ON ENDIF getbyte3 btfss PIR1,RCIF ; while(!RCIF) goto getbyte movf RCREG,w ; RCREG return ;******************** write eeprom subroutine ********************************* write_eeprom movf address,w movwf tmpaddr ; tmpaddr = address movf address+1,w movwf tmpaddr+1 clrf count ; count=0 write_loop movlw NumRetries+1 ; retry = NumRetries+1 movwf retry w_e_l_1 movf amount,w subwf count,w ; while (count program memory clrf STATUS movlw high (LoaderStart) ; if (tmpaddr >= LoaderStart) ............... subwf tmpaddr+1,w movlw low (LoaderStart) ; mask Booloader, [ICD-Debugger], btfsc STATUS,Z ; __IDLOCS & __CONFIG subwf tmpaddr,w btfsc STATUS,C goto next_adr ; next address goto w_e_l_3 data_eeprom bcf EECON1,EEPGD ; EEPGD = 0 -> data memory clrf STATUS w_e_l_3 movf tmpaddr,w bsf STATUS,RP1 movwf EEADR ; EEADR = low tmpaddr bcf STATUS,RP1 movf tmpaddr+1,w ; if (tmpaddr < 0x0004) ..................... btfss STATUS,Z goto w_e_l_4 movlw 4 subwf tmpaddr,w btfsc STATUS,C goto w_e_l_4 bsf STATUS,RP1 ; (bank3) bsf STATUS,RP0 btfss EECON1,EEPGD ; skip if (EEPGD) goto w_e_l_31 bcf STATUS,RP0 ; (bank2) movlw low UserStart+1 ; EEADRL + low UserStart+1 addwf EEADR,f ; (relocated first 4 user instructions) w_e_l_31 clrf STATUS ; (bank0) movlw high UserStart ; EEADRH = high UserStart goto w_e_l_5 w_e_l_4 movf tmpaddr+1,w ; EEADRH = high tmpaddr w_e_l_5 bsf STATUS,RP1 movwf EEADRH ; set EEADRH movf INDF,w movwf EEDATH ; EEDATH = buff[count] incf FSR,f movf INDF,w movwf EEDATA ; EEDATA = buff[count+1] bsf STATUS,RP0 bsf EECON1,WREN ; WREN=1 movlw 0x55 ; EECON2 = 0x55 movwf EECON2 movlw 0xAA ; EECON2 = 0xAA movwf EECON2 bsf EECON1,WR ; WR=1 nop ; instructions are ignored nop ; microcontroller waits for a complete write clrf STATUS wait_write clrwdt btfss PIR2,EEIF ; necessary for a write to data eeprom goto wait_write bcf PIR2,EEIF bsf STATUS,RP0 ; (bank3) bsf STATUS,RP1 bcf EECON1,WREN ; WREN=0 bsf EECON1,RD ; RD=1 nop nop bcf STATUS,RP0 ; (bank2) decf FSR,f movf INDF,w ; if ((EEDATH != buff[count]) || (EEDATA != buff[count+1])) xorwf EEDATH,w btfss STATUS,Z goto w_e_l_6 ; repeat write incf FSR,f movf INDF,w xorwf EEDATA,w btfsc STATUS,Z goto next_adr ; verification OK, next address w_e_l_6 clrf STATUS ; (bank0) decfsz retry,f goto w_e_l_1 ; if (--retry != 0) repeat write retlw 0 ; else return 0 (BAD) next_adr bcf STATUS,RP1 movlw 2 ; count := count + 2 addwf count,f incf tmpaddr,f ; tmpaddr := tmpaddr + 1 btfsc STATUS,Z incf tmpaddr+1,f goto write_loop ;------------------------------------------------------------------------------ END