Yes software is seldom broken out - the space shuttle software spent $200 million, with an original estimate of $20 Million according to https://history.nasa.gov/computers/Ch4-5.html. I guess thats in 1970-1980 dollars
For the 777 it would be even harder to break out a software only a number only because while there will be new lines of code written there will also be many more old lines of code reused from earlier models.
