as any other linux distribution everything is supported that the kernel can do

so if you need more than what the 2.4 kernel already supports you need to compile additional modules or a new kernel.
i wouldnt recommend making a list of what the kernel supports - would be a tremendously huge list of hardware and it would change between kernel versions that are compiled with different build-in modules.
a better question would be: what does the stock kernel that comes with the device does not support.
for example i read of printer, hsdpa and usb storage modules that are supplied by cnm for their netbook [1] which suggests that these functionalities are not included in the stock version.
[1]
http://194.150.201.35/cnmlifestyle/cnmbookdownloads.htm