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Duesentrieb7
27.08.2008, 10:40
Hallo,

das Thema Bootloader bring mich langsam zur Verzweiflung.

Habe das Sample "bootloader.bas" auf meine ATmega128 angepasst:



'----------------------------------------------------------------
' (c) 1995-2005, MCS
' Bootloader.bas
' This sample demonstrates how you can write your own bootloader
' in BASCOM BASIC
' VERSION 2 of the BOOTLOADER. The waiting for the NAK is stretched
' further a bug was resolved for the M64/M128 that have a big page size
'-----------------------------------------------------------------
'This sample will be extended to support other chips with bootloader
'The loader is supported from the IDE

$crystal = 4096000
$baud = 19200 'this loader uses serial com
'It is VERY IMPORTANT that the baud rate matches the one of the boot loader
'do not try to use buffered com as we can not use interrupts

$regfile = "m128def.dat"
Const Loaderchip = 128

$loader = &HFC00 ' 1024 words
Const Maxwordbit = 7 'Z7 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
'Mega 88 : 32 words, 128 pages

Disable Interrupts 'we do not use ints

'some constants used in serial com
Const Nak = &H15
Const Ack = &H06
Const Can = &H18

'we use some leds as indication in this sample , you might want to remove it
Config Pinc.0 = Output
Portc.0 = 1 'the stk200 has inverted logic for the leds
Config Pinc.1 = Output
Portc.1 = 1

$timeout = 400000 'we use a timeout
'When you get LOADER errors during the upload, increase the timeout value
'for example at 16 Mhz, use 200000

Bretries = 5 'we try 5 times
Testfor123:

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 Testfor123 'we test again
End If

For J = 1 To 10 'this is a simple indication that we start the normal reset vector
Toggle Portc.0 : Waitms 100
Next

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 Portc.0 : 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

Portc.1 = 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 Portc.0 : Waitms 10 : Toggle Portc.0 '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}

#if(loaderchip = 128) Or(loaderchip = 2561)
lds r24,{Z+2}
sts rampz,r24 ' we need to set rampz also for the M128
#endif

Spmcsr = Spmcrval 'assign register
spm 'this is an asm instruction
nop
nop
Return


Die Übertragung startet und läuft bis zum Ende durch.
Leider startet mein Programm danach nicht :(
Nachdem ich die CPU ausgelesen habe, musste ich feststellen,
dass das Programm nur bis zur Adresse $7400 übertragen wird
und der Rest einfach mit "FF" gefüllt ist...
Was mache ich falsch?

Danke und Gruß,
Frank