Bootloader secrets I do not understand

Arera · Joined: 23 Sep 2007 Posts: 375 Location: Wuppertal, Germany

Hi all,

my DIY bootloader does not work....
I copy the new prog to an EEPROM and flash from there. Works so far.

Here's my problem:

If the lenght of the prog (the used flash) changes, I noticed that the .hex changes at adresee h003E /h003F.
After bootloding from my EEPROM (it contains the proper values, promised), these values read not the values I wrote?!

If I use the MCS-bootloader, these adresses change to the proper values.
I noticed, that the MCS-BL appends a couple of h1A-bytes. should I do the same, and how?

(BASCOM-AVR version : 2.0.7.7 )

Arera · Joined: 23 Sep 2007 Posts: 375 Location: Wuppertal, Germany

I admitt: My question is a bit messy...
I found out by myself what was missing:
I left out all the indented lines, which leads to wired behavior. Thanks to the 71 viewers anyway!

write_EEPROM_to_flash:
Spmcrval = 3 : Gosub Do_spm ' erase the first page
Spmcrval = 17 : Gosub Do_spm ' re-enable page

for x = 0 to number_of_Pages
load the buffer
gosub writepage
next x

Wrd = 0 'Z pointer needs wrd to be 0
Spmcrval = 5 : Gosub Do_spm 'write page
Spmcrval = 17 : Gosub Do_spm ' re-enable page

Goto _reset