On Thu, Jun 28, 2007 at 10:59:35AM +0200, Segher Boessenkool wrote:
> > Here is an implementation to allow PReP systems to boot under the
> > arch/powerpc codebase, one of the few remaining platforms supported in
> > arch/ppc but not so far in arch/powerpc.
>
> > Too big for the list, the patch is at:
> > http://ozlabs.org/~dgibson/home/prep-support
>
> Too lazy to split the patch into bite-size chunks, you mean ;-)
Well... much as I like small patches, I don't really like having a big
string of patches, each of which does basically nothing on its own,
i.e. split up just for the sake of making smaller, rather than into
separate logically separate changes.
> Anyway, here goes the DTS bits:
>
> +/*
> + * PReP skeleton device tree
> + *
> + * Paul Mackerras <[EMAIL PROTECTED]>
> + */
> +
> +/ {
> + device_type = "prep";
> + model = "IBM,PReP";
>
> Not specific enough, leave it out or fill it in in the bootwrapper.
Yeah, I should fill that in with the string from the residual data.
Haven't gotten around to it.
> + compatible = "prep";
>
> Maybe fill this in, too.
>
> + #address-cells = <1>;
> + #size-cells = <1>;
> +
> + cpus {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + [EMAIL PROTECTED] {
>
> Do all (supported) PReP boards have one CPU only?
Well, depends what you mean by "supported", really. My arch/powerpc
port only support UP boards so far... I realise this will need to
change at some point.
>
> + device_type = "cpu";
> + reg = <0>;
> + clock-frequency = <0>; // filled in by bootwrapper
> + bus-frequency = <0>; // filled in by bootwrapper
> + timebase-frequency = <0>; // filled in by bootwrapper
> + i-cache-line-size = <0>; // filled in by bootwrapper
> + d-cache-line-size = <0>; // filled in by bootwrapper
> + d-cache-size = <0>; // filled in by bootwrapper
> + i-cache-size = <0>; // filled in by bootwrapper
> + external-control;
>
> Really?
No idea, just copied that from earlier work of Paulus'. Don't even
know what the property means.
> + graphics;
> + performance-monitor;
> +
> + l2-cache {
> + device_type = "cache";
> + i-cache-size = <00100000>;
> + d-cache-size = <00100000>;
> + i-cache-sets = <00008000>;
> + d-cache-sets = <00008000>;
> + i-cache-line-size = <00000020>;
> + d-cache-line-size = <00000020>;
>
> Drop the leading zeroes, they make my head spin :-)
>
> + cache-unified;
> + };
> + };
> + };
> +
> + memory {
> + device_type = "memory";
> + // dummy range here, zImage wrapper will fill in the actual
> + // amount of memory from the residual data
> + reg = <00000000 00000000>;
> + };
> +
> + [EMAIL PROTECTED] {
> + device_type = "pci";
> + compatible = "prep";
>
> Is that specific enough?
Well, AFAICT, the prep PCI code doesn't need any more info.
> + clock-frequency = <01fca055>;
> + reg = <80000000 7effffff>;
> + 8259-interrupt-acknowledge = <bffffff0>;
> + #address-cells = <3>;
> + #size-cells = <2>;
> + ranges=<01000000 00000000 00000000 80000000 00000000 00800000
> + 01000000 00000000 00800000 81000000 00000000 3e800000
> + 02000000 00000000 00000000 c0000000 00000000 01000000
> + 02000000 00000000 01000000 c1000000 00000000 3e000000>;
> + interrupt-map-mask = <f800 0 0 7>;
> + interrupt-map = <6000 0 0 1 &MPIC 6 0
> + 8000 0 0 1 &MPIC 7 0
> + 9000 0 0 1 &MPIC 2 0
> + b000 0 0 1 &MPIC 1 0>;
>
> I can't believe this "ranges" and interrupt mapping will
> work on all PReP systems...
Probably not, but it should work on a chunk of them. Like I say,
there's still a good deal more that needs to be filled in from
residual data or wherever.
> + isa {
> + device_type = "isa";
> + #address-cells = <2>;
> + #size-cells = <1>;
> + #interrupt-cells = <2>;
> + ranges = <00000001 00000000
> + 01005800 00000000 00000000 00010000
> + 00000000 00000000
> + 02005800 00000000 00000000 01000000>;
> +
> + parallel {
> + device_type = "parallel";
> + compatible = "ecp", "pnpPNP,400";
>
> "pnpPNP,401", "pnpPNP,400"
>
> + reg = <00000001 000003bc 00000008
> + 00000001 000007bc 00000006>;
> + interrupts = <00000007 00000003>;
> + interrupt-parent = <&PIC8259>;
> + };
> +
> + [EMAIL PROTECTED] {
> + device_type = "serial";
> + compatible = "pnpPNP,501";
>
> "pnpPNP,501", "pnpPNP,500" I'd say. Many/some device
> tree users will only care it is _some_ 8250 family thing.
>
> + clock-frequency = <001c2000>;
> + reg = <00000001 000003f8 00000008>;
> + interrupts = <00000004 00000003>;
> + interrupt-parent = <&PIC8259>;
> + };
> + [EMAIL PROTECTED] {
> + device_type = "serial";
> + compatible = "pnpPNP,501";
> + clock-frequency = <001c2000>;
> + reg = <00000001 000002f8 00000008>;
> + interrupts = <00000003 00000003>;
> + interrupt-parent = <&PIC8259>;
> + };
> + PIC8259: interrupt-controller {
> + device_type = "i8259";
>
> device_type = "interrupt-controller".
>
> + compatible = "prep,iic";
> + reg = < 00000001 00000020 00000002
> + 00000001 000000a0 00000002
> + 00000001 000004d0 00000002>;
> + interrupts = <00000000 00000003
> + 00000002 00000003>;
> + interrupt-parent = <&MPIC>;
> + };
> + };
> +
> + MPIC: [EMAIL PROTECTED] {
> + device_type = "open-pic";
>
> device_type = "interrupt-controller".
>
> + compatible = "mpic";
> + reg = < 00006800 00000000 00000000 00000000 00000000
> + 02006810 00000000 00000000 00000000 00040000>;
> + assigned-addresses = <
> + 82006810 00000000 3afc0000 00000000 00040000>;
> + };
> + };
> +
> + chosen {
> + linux,stdout-path = "/pci/isa/[EMAIL PROTECTED]";
> + };
> +};
>
> What is the plan here -- have the bootwrapper build the
> device tree / fill in the details from the residual data?
Not sure at this stage if it will be best for the bootwrapper to build
a complete tree from residual, or to have a dts skeleton with
substantial chunks filled in by bootwrapper from residual. I was
intending to merge libfdt into the kernel for more flexible device
tree manipulation before investigating that further.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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