Port Address

The base port numbers and addresses for the OLPC platform as established by Open Firmware are as follows.

Please note - these ports and addresses are written to MSR registers by the firmware - other Geode BIOS implementations may use different values. When in doubt, you can always get the base addresses by scanning the PCI configuration.

I/O ports

18b0 : SMBUS
1000 : GPIO
1800 : MFGPT
1880 : IRQ mapper
1400 : PM
1841 : ACPI
1480 : AC-97. Audio Codec: Explanations are in Datasheet Page 9

Memory space

fd000000 : Frame buffer
fe000000 : Graphics processor
fe004000 : Video processor
fe008000 : Display controller.
           Display/Video/Graphics Controller/processor: Explanation in Geode Gx datasheet Chapter 6
fe01a000 : OHCI (USB1)
fe01b000 : EHCI (USB2)
efc00000 : UOC (USB option controller).
           USB Controller: Explanation in AMD Geode Companion Device Databook Chapter 5.5
fe00c000 : CaFe NAND
fe010000 : CaFe SD
fe014000 : CaFe Camera

These addresses can be "discovered" by doing PCI configuration reads to PCI device base address registers or by browing the Open Firmware device tree.