N900

Camera
Camera (front & back) drivers are available from this git:. The code is not in the mainline kernel, because of the non-free camera firmware. The driver is supposed to be rewritten to avoid this firmware.

U-Boot
Instead of booting the kernel directly from NOLO (which restricts you to using ONE kernel), U-Boot can be used as second bootloader. The Boot Process will end up like this: NOLO -> U-Boot -> Kernel. The Maemo kernel is appended to U-Boot, since U-Boot will be at the location where the Maemo kernel is located normally.

The U-Boot patches to support the N900 are not yet mainline, but have been proposed for inclusion recently: U-Boot RX51 support