Mindboards

I'm trying to get back to life an old NXT 1.0 brick. As part of the challenge I have decided to use NBC/NXC as programming languages and set up my development environment in Linux. I was able to compile simple programs and download them to NXT, everything working as expected, but I have found no way to download the enhanced firmware. Typing nbc -help shows an option "-EF : enhanced firmware", but I confess not tried it, afraid of breaking something. Maybe I missed some documentation, but I have found no way of downloading (flashing is a better term?) the enhanced firmware using only linux command line to a NXT connected via USB. Any help will be truly appreciated

Have you checked out John Hansen's tools at http://bricxcc.sourceforge.net/
I have only used NexT Tool for Mac, using the GUI interface to download new firmware.
I believe that the command line tools should work as well but I haven't tried it myself.