Hi Carlos, sorry to hear of you near disaster, happy to hear you got it fixed. You must have deleted one of the required packages since deleting anything I added would not prevent it from working.
As far as the E2100L goes you can follow this detailed info for WRT160NL found at http://wiki.openwrt.org/toh/linksys/wrt160nl. Except for editing the two source files previously described the procedure for the E2100L is identical. You will see by the pictures you can't tell the two apart by looking at the internals. It also has a very good description of how to use the serial console and pinouts.
When you execute "make menuconfig" all required settings are defaulted. I didn't deselect anything but I did add quite a bit. My problem is I don't remember what I added and what was already there. I would have to clean it up and start from scratch to figure that out. I added the Luci package and several modules for the web interface. I also made necessary additions for USB mounting using VFAT NTFS and EXFAT file systems. As requested earlier in this thread I added CIFS functionality. Also added the necessary ushare or minidlna depending on the build. Hint, you need to select necessary libraries/packages before they show up in the Luci section. I did a lot of experimentation adding packages via the Luci interface on a basic build. Then I would add them though the menuconfig and do another compile. That's where I'm at now. I just do a SVN update, update the feeds and recompile. The only thing I've added that's not posted is a simple text editor, nano in my case. Me and Vi just don't get along.
If you want to start from my current configuration I can post it or somewhere e-mail it to you. I do highly recommend you get the serial console to working if you are going to load your own compiled version. The bins I've provided have all been tested for at least a couple of hours before I posted them. While booting using the failsafe method does work I've found it much easier to just plug in the TTL cable and use that method. I wish someone would sell a cable configured to use the Ethernet port to access the serial console. I tried to make one but I'm just not creative enough I guess.
Bottom line, if you follow the wiki guidlines, don't remove any selections already made in the menuconfig program, and compile without errors, you should end up with a bootable bin. I don't recommend ever using the sysupgrade bin, every time I've tried I had to hook up the serial cable to recover. I always uncheck the save settings box when upgrading via Luci and only use the system bin.
(Last edited by jimfree on 20 Mar 2013, 03:26)