Thanks for the tip. I did couple of tries with skip and it seems to be the size (time) issue not the place in memory where I do write.
Every try with larger amount of data fails with those two lines (or very similiar):
Code:
boot: C def:rst:reset=hard:version=174700
kernel: E wdog:Abnormal reset detected but saved buffer invalid:
while similiar attempts with smaller amount of data success (the script brakes later on the above way anyway).
Wojtek