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:
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
Läuft mit 38400 Baud ohne Probleme.
Die Fuseeinstellungen siehe Bild.
Ich habe den Mega 32 auch gegen Auslesen geschützt.
Nun kommtnoch ein Krüptfunction rein 
Bild hier
Grüße Gento
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