Red Hat Bugzilla – Bug 186564
ACPI 2.0 systems with no XSDT fail to boot
Last modified: 2007-11-30 17:07:24 EST
Description of problem:
The ACPI routines make a blunt assumption that if a system is ACPI 2.0
compliant an XSDT table will be present. This does not appear to be a
requirement of the ACPI 2.0 spec. However, the spec does not outline how to
properly signify that no XSDT table is present. If a BIOS leaves the XSDT
pointer field in the RSDP NULL'd or set to any other value to indicate that it
is invalid the ACPI routine will try to use this as the address of the XSDT.
Upon failure of validating the XSDT, the ACPI system will not fall back and use
the RSDT pointer.
Version-Release number of selected component (if applicable):
Any machine that has ACPI v2.0 without XSDT table.
Steps to Reproduce:
1. Boot Linux
The patch for this had been submitted to the ACPI maintaners. The patch
had been submitted as ACPI CA release. git-commit:
Created attachment 126625 [details]
Back-port from 2.6.12 to 2.6.9
Patch applies cleanly to RHEL4 U3.
Patch posted for review.
*** This bug has been marked as a duplicate of 165809 ***