I was reading a bit around about openwrt and I recognized, that with 16 MB it wont be fun with 2 MB spare memory. After reading some FAQs and Wikis I found out, that some V2 are shipped with 32 MB but only 16 MB enables ... this rocks .. more space for packages on openwrt.
So I looked for my board revision .. and yes it was a Revision XH 2.0. Hmm ... good, but there are some of these boards, which have anyways 16 MB. So I opened the box (and lost my guaranty) an looked on the 2 memory chips. There are 2 IS42S16800A-7T mounted, which seems to be save to be 2x16 MB chips. Also save seems to be IC42S16800-7T ... which looks like -7T's to be working.
Boards with IC42S16400-6T aren't working, like all other except -7T's, you have been warned!
After I was sure I have the correct chips mounted, I did the following:
~ # nvram set sdram_init=0x0008
~ # nvram set sdram_ncdl=0x0000
~ # nvram commit
~ # reboot
Now I did wait until the box was back and then:
~ # free
total used free shared buffers
Mem: 30272 13836 16436 0 1904
Swap: 0 0 0
Total: 30272 13836 16436
Yippiyayeah! Thats great! :-)