On Wed, Mar 28, 2012 at 09:20:05PM +0800, Jiang Liu wrote:
>On 03/28/2012 05:30 PM, Richard Yang wrote:
>> Experts
>>
>> I am reading the PCI enumeration code on x86. One thing on ACPI
>> namespace puzzles me.
>>
>> In the initialize process, the call flow is like this
>> acpi_pci_root_add()
>> try_get_root_bridge_busnr()
>> acpi_walk_resources(handle, METHOD_NAME__CRS,
>> get_root_bridge_busnr_callback, res)
>This piece of code is to invoke ACPI method "_CRS" for "handle", and call
>get_root_bridge_busnr_callback for each resource descriptor returned by
>this method.
>Here "handle" is the object for the pci root bus or PCI host bridge.
>"_CRS" is the name of ACPI method, which exists under "handle".
>
>>
Thanks for your clarification.
I read the acpi code again. And found the namespace tree is created in
acpi_scan_init()
{
...
result = acpi_bus_scan(ACPI_ROOT_OBJECT, &ops, &acpi_root);
...
}
And then call the acpi_walk_namespace() to go through the whole
namespace. Am I right? And form those handles
I look at the SPEC and code again and find the namespace is loaded
by acpi_ns_load_namespace() right?
It will read DSDT/SSDT/PSDT by calling acpi_ns_load_table_by_type.
While I grep the whole source code, but not find the definition of this
function.
--
Richard Yang
Help you, Help me
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