LD bug?

[Witness]

I've been working on an OS for a little while, and have been coming across
some assemly errors. So I just converted an Intel format program to AT&T
format so I could compile it under 'as' and link it with 'ld'.  However, I
am getting a linking error from 'ld' saying that references to 'ds' and 'di'
are not found, and the only place I can find that I did not use the % sign
(as required by AT&T) were places that were legal, and are at the following:

[nboot.s:49]
        ldsw    ds(%bx,1), %si
[nboot.s:181]
        movw    %es:di, %ax
[nboot.s:190]
        movw    %es:di, %ax

here's the output of my makefile:

as -o nyaos nboot.s
ld -Ttext 0x0 -s --oformat binary -o nyaos.img nyaos
nyaos(.text+0x65): undefined reference to `ds'
nyaos(.text+0x137): undefined reference to `di'
nyaos(.text+0x14c): undefined reference to `di'
make: *** [make_nyaos] Error 1

The files are posted at:

http://bmeyer67.resnet.calvin.edu/Winux/NYAOS/
http://bmeyer67.resnet.calvin.edu/Winux/NYAOS/Makefile
http://bmeyer67.resnet.calvin.edu/Winux/NYAOS/nboot.s
http://bmeyer67.resnet.calvin.edu/Winux/NYAOS/nyaos.asm

Am I doing anything wrong? Or is this a bug with 'ld'?

Thanks for the help in advance,

Benjamen R. Meyer