I guess it depends what you mean with "access". Just for "fun" you could probably read some contents with commands like:
tc@box:~$ hexdump -vC /dev/nvram
00000000 00 00 00 00 00 00 0e 80 02 ff ff 00 00 00 00 00 |................|
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000020 02 8e ff ff 20 00 00 07 00 20 20 00 00 00 00 31 |.... .... ....1|
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000050 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000070 00 00 |..|
00000072
tc@box:~$ cat /proc/driver/nvram
Checksum status: valid
# floppies : 0
Floppy 0 type : none
Floppy 1 type : none
HD 0 type : none
HD 1 type : none
HD type 48 data: 0/0/0 C/H/S, precomp 0, lz 0
HD type 49 data: 7/32/0 C/H/S, precomp 32, lz 0
DOS base memory: 640 kB
Extended memory: 65535 kB (configured), 65535 kB (tested)
Gfx adapter : EGA, VGA, ... (with BIOS)
FPU : installed
tc@box:~$
There are certainly some other tools, but I just could not be bothered to use goggle to find out more.