Is OLPC going for ACPI support?

Manish Regmi manish at olpcnepal.org
Tue Mar 6 05:33:25 EST 2007


On 3/5/07, Mitch Bradley <wmb at firmworks.com> wrote:
>

> The suspend/resume code uses MSR registers that are documented in the
> AMD chip specs for the Geode GX and 5536 companion chips.  The I/O ports
> are either legacy PC ports (for example the interrupt controller and
> interval timer) or Geode-specific devices documented by the AMD chip
> spec (for example MFGPT and SMBUS registers).  The OLPC wiki has
> pointers to those AMD chip specs.  The base port numbers and addresses
> for the Geode devices are established by MSR registers, as follows:
>
> I/O ports:
>
> 18b0 SMBUS
> 1000 GPIO
> 1800 MFGPT
> 1880 IRQ mapper
> 1400 PM
> 1841 ACPI
> 1480 AC-97
>
> Memory space:
>
> fd000000 Frame buffer
> fe000000 Graphics processor
> fe004000 Video processor
> fe008000 Display controller
> fe01a000 OHCI (USB1)
> fe01b000 EHCI (USB2)
> efc00000 UOC (USB option controller)
> 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.
>
> There are a very small number of registers that the AMD public specs
> list as reserved, but the code has to use anyway.  AMD told us the
> required settings for those registers.  There are really very few such
> registers.  The vast majority of the registers are fully documented in
> AMD's public specs.
>
> AMD employees and former employees, particularly Jordan Crouse and Tom
> Sylla, have helped us a lot.  Even with the extensive documentation, it
> requires a lot of time and experience to understand how everything fits
> together.  Without the extensive handholding that those two people gave
> me, I would not have been able to figure it all out.  Thanks, Jordan and
> Tom!
>

Thanks for such a nice info. I have created a wiki based on your
information http://wiki.laptop.org/go/Port_Address.

Are these ports and MMIO address fixed or generated at runtime by
firmware/bios?

Thanks...

-- 
--------------------------------------------------------
Manish Regmi
Volunteer
OLPC Nepal



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