So ich habe den Bootloader mit dem Mega 32 am Laufen.
Der Code ganz knapp unter 2K Byte mit LCD Anzeige und dem Orginal von MCS
abgewandelt:Läuft mit 38400 Baud ohne Probleme.Code:$crystal = 16000000 $baud = 38400 'this loader uses serial com $regfile = "m32def.dat" Config Portb = Output Config Lcd = 20 * 2 Config Lcdpin = Pin , Db4 = Portb.0 , Db5 = Portb.1 , Db6 = Portb.2 , Db7 = Portb.3 , E = Portb.6 , Rs = Portb.5 Config Lcdbus = 4 Config Pind.0 = Input 'RxD für RS232 Config Pind.1 = Output 'TxD für RS232 Const Loaderchip = 32 ' Mega32 $loader = $3c00 '$3800= 2048 word $3c00= 1024 words Const Maxwordbit = 6 'Z6 is maximum bit ' Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0 Const Maxword =(2 ^ Maxwordbit) * 2 '128 Const Maxwordshift = Maxwordbit + 1 'Dim the used variables Dim Bstatus As Byte , Bretries As Byte , Bblock As Byte , Bblocklocal As Byte Dim Bcsum1 As Byte , Bcsum2 As Byte , Buf(128) As Byte , Csum As Byte Dim J As Byte , Spmcrval As Byte ' self program command byte value Dim Z As Long 'this is the Z pointer word Dim Vl As Byte , Vh As Byte ' these bytes are used for the data values Dim Wrd As Word , Page As Word 'these vars contain the page and word address Dim Bkind As Byte , Bstarted As Byte Disable Interrupts 'we do not use ints 'some constants used in serial com Const Nak = &H15 Const Ack = &H06 Const Can = &H18 $timeout = 200000 'we use a timeout 'When you get LOADER errors during the upload, increase the timeout value 'for example at 16 Mhz, use 200000 Waitms 100 Initlcd Cls Cursor Off Noblink Locate 1 , 1 Lcd "Boote ..... " Locate 2 , 1 Lcd "...................." Locate 2 , 1 For J = 0 To 20 Lcd " " Waitms 150 Bretries = 5 'we try 5 times Teste_ob_was_kommt: Bstatus = Waitkey() 'wait for the loader to send a byte Print Chr(bstatus); If Bstatus = 123 Then 'did we received value 123 ? Bkind = 0 'normal flash loader Goto Loader Elseif Bstatus = 124 Then ' EEPROM Bkind = 1 ' EEPROM loader Goto Loader Elseif Bstatus <> 0 Then Decr Bretries If Bretries <> 0 Then Goto Teste_ob_was_kommt 'we test again End If Next J Goto _reset 'goto the normal reset vector at address 0 'this is the loader routine. It is a Xmodem-checksum reception routine Loader: Do Bstatus = Waitkey() Loop Until Bstatus = 0 For J = 1 To 3 'this is a simple indication that we start the normal reset vector Toggle Portb.2 : Waitms 50 Next If Bkind = 0 Then Spmcrval = 3 : Gosub Do_spm ' erase the first page Spmcrval = 17 : Gosub Do_spm ' re-enable page End If Bretries = 10 'number of retries Do Bstarted = 0 ' we were not started yet Csum = 0 'checksum is 0 when we start Print Chr(nak); ' firt time send a nack Do Bstatus = Waitkey() 'wait for statuse byte Select Case Bstatus Case 1: ' start of heading, PC is ready to send Incr Bblocklocal 'increase local block count Csum = 1 'checksum is 1 Bblock = Waitkey() : Csum = Csum + Bblock 'get block Bcsum1 = Waitkey() : Csum = Csum + Bcsum1 'get checksum first byte For J = 1 To 128 'get 128 bytes Buf(j) = Waitkey() : Csum = Csum + Buf(j) Next Bcsum2 = Waitkey() 'get second checksum byte If Bblocklocal = Bblock Then 'are the blocks the same? If Bcsum2 = Csum Then 'is the checksum the same? Gosub Writepage 'yes go write the page Print Chr(ack); 'acknowledge Else 'no match so send nak Print Chr(nak); End If Else Print Chr(nak); 'blocks do not match End If Case 4: ' end of transmission , file is transmitted If Wrd > 0 Then 'if there was something left in the page Wrd = 0 'Z pointer needs wrd to be 0 Spmcrval = 5 : Gosub Do_spm 'write page Spmcrval = 17 : Gosub Do_spm ' re-enable page End If Print Chr(ack); ' send ack and ready Portb.3 = 0 ' simple indication that we are finished and ok Waitms 20 Goto _reset ' start new program Case &H18: ' PC aborts transmission Goto _reset ' ready Case 123 : Exit Do 'was probably still in the buffer Case 124 : Exit Do Case Else Exit Do ' no valid data End Select Loop If Bretries > 0 Then 'attempte left? Waitms 1000 Decr Bretries 'decrease attempts Else Goto _reset 'reset chip End If Loop 'write one or more pages Writepage: If Bkind = 0 Then For J = 1 To 128 Step 2 'we write 2 bytes into a page Vl = Buf(j) : Vh = Buf(j + 1) 'get Low and High bytes lds r0, {vl} 'store them into r0 and r1 registers lds r1, {vh} Spmcrval = 1 : Gosub Do_spm 'write value into page at word address Wrd = Wrd + 2 ' word address increases with 2 because LS bit of Z is not used If Wrd = Maxword Then ' page is full Wrd = 0 'Z pointer needs wrd to be 0 Spmcrval = 5 : Gosub Do_spm 'write page Spmcrval = 17 : Gosub Do_spm ' re-enable page Page = Page + 1 'next page Spmcrval = 3 : Gosub Do_spm ' erase next page Spmcrval = 17 : Gosub Do_spm ' re-enable page End If Next Else 'eeprom For J = 1 To 128 Writeeeprom Buf(j) , Wrd Wrd = Wrd + 1 Next End If Toggle Portb.2 : Waitms 10 : Toggle Portb.2 'indication that we write Return Do_spm: Bitwait Spmcsr.0 , Reset ' check for previous SPM complete Bitwait Eecr.1 , Reset 'wait for eeprom Z = Page 'make equal to page Shift Z , Left , Maxwordshift 'shift to proper place Z = Z + Wrd 'add word lds r30,{Z} lds r31,{Z+1} Spmcsr = Spmcrval 'assign register spm 'this is an asm instruction nop nop Return
Die Fuseeinstellungen siehe Bild.
Ich habe den Mega 32 auch gegen Auslesen geschützt.
Nun kommtnoch ein Krüptfunction rein
Bild hier
Grüße Gento
Zitieren
Lesezeichen