You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
144 lines
2.7 KiB
144 lines
2.7 KiB
/*++
|
|
|
|
Copyright (c) 1997 Microsoft Corporation
|
|
All rights reserved
|
|
|
|
Module Name:
|
|
|
|
acpidtct.c
|
|
|
|
Abstract:
|
|
|
|
This module peruses the ACPI tables looking for specific
|
|
entries.
|
|
|
|
Author:
|
|
|
|
Matt Holle (matth) (shamefully stolen from jakeo's x86 code)
|
|
|
|
Environment:
|
|
|
|
|
|
Revision History:
|
|
|
|
|
|
--*/
|
|
#include "stdlib.h"
|
|
#include "string.h"
|
|
#include "bldr.h"
|
|
#include "acpitabl.h"
|
|
#include "efi.h"
|
|
#include "extern.h"
|
|
|
|
PDESCRIPTION_HEADER
|
|
BlFindACPITable(
|
|
IN PCHAR TableName,
|
|
IN ULONG TableLength
|
|
)
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
Given a table name, finds that table in the ACPI BIOS
|
|
|
|
Arguments:
|
|
|
|
TableName - Supplies the table name
|
|
|
|
TableLength - Supplies the length of the table to map
|
|
|
|
Return Value:
|
|
|
|
Pointer to the table if found
|
|
|
|
NULL if the table is not found
|
|
|
|
Note:
|
|
|
|
This function is not capable of returning a pointer to
|
|
a table with a signature of DSDT. But that's never necessary
|
|
in the loader. If the loader ever incorporates an AML
|
|
interpreter, this will have to be enhanced.
|
|
|
|
--*/
|
|
|
|
{
|
|
ULONG Signature;
|
|
PDESCRIPTION_HEADER Header;
|
|
ULONG TableCount;
|
|
ULONG i;
|
|
PXSDT xsdt = NULL;
|
|
PRSDP rsdp = (PRSDP)AcpiTable;
|
|
|
|
UNREFERENCED_PARAMETER( TableLength );
|
|
|
|
//DbgPrint("Hunting for table %s\n", TableName);
|
|
|
|
//
|
|
// Sanity Check.
|
|
//
|
|
|
|
if (rsdp) {
|
|
|
|
//DbgPrint("Looking through 2.0 RSDP: %p\n", rsdp20);
|
|
xsdt = (PVOID)rsdp->XsdtAddress.QuadPart;
|
|
if (xsdt->Header.Signature != XSDT_SIGNATURE) {
|
|
|
|
//
|
|
// Found ACPI 2.0 tables, but the signature
|
|
// is garbage.
|
|
//
|
|
|
|
return NULL;
|
|
}
|
|
|
|
} else {
|
|
|
|
//
|
|
// Didn't find any tables at all.
|
|
//
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
Signature = *((ULONG UNALIGNED *)TableName);
|
|
|
|
//
|
|
// If they want the root table, we've already got that.
|
|
//
|
|
if (Signature == XSDT_SIGNATURE) {
|
|
|
|
return(&xsdt->Header);
|
|
|
|
} else {
|
|
|
|
TableCount = NumTableEntriesFromXSDTPointer(xsdt);
|
|
|
|
//DbgPrint("xSDT contains %d tables\n", TableCount);
|
|
|
|
//
|
|
// Sanity check.
|
|
//
|
|
if( TableCount > 0x100 ) {
|
|
return(NULL);
|
|
}
|
|
|
|
//
|
|
// Dig.
|
|
//
|
|
for (i=0;i<TableCount;i++) {
|
|
|
|
Header = (PDESCRIPTION_HEADER)(xsdt->Tables[i].QuadPart);
|
|
|
|
if (Header->Signature == Signature) {
|
|
|
|
//DbgPrint("Table Address: %p\n", Header);
|
|
return(Header);
|
|
}
|
|
}
|
|
}
|
|
|
|
//DbgPrint("Table not found\n");
|
|
return(NULL);
|
|
}
|