Files
xen/tools/libacpi
Jan Beulich f2ff80877f x86/vRTC: support century field
Both ROMBIOS and SeaBIOS (with CONFIG_QEMU=y, as we build it) blindly
assume availability of this field (at its conventional index 0x32); OVMF
at least has code to inspect FADT. Hence we ought to have supported it
virtually forever.

As the index is beyond RTC_CMOS_SIZE, leverage the padding field in
struct hvm_hw_rtc to hold its value. Update the field only when involved
values are valid BCD century specifiers. Otherwise (for VMs migrated in
from an older hypervisor) leave handling to the DM.

This makes the Linux rtc-cmos driver report y3k compatibility.

In the new rtc_check(), besides checking the new fields also check the
pre-existing pad0 field.

While extending xen-hvmctx.c:dump_rtc() also add RTC offset there.

Fixes: 4ca1612143 ("[HVM] Move RTC emulation into the hypervisor")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger@xenproject.org>
2026-09-02 15:14:08 +02:00
..

ACPI builder for domain firmware


BUILDING ACPI
-----------------
Users of ACPI builder are expected to provide an include file that makes available
the following:
* strncpy
* printf
* NULL
* test_bit
* offsetof

When compiling build.c, the name of this include file should be given to
compiler as -DLIBACPI_STDUTILS=\"<filename>\". See tools/firmware/hvmloader/Makefile
for an example.

Note on DSDT Table
------------------
DSDT table source code is acpi_dsdt.asl
It is already compiled and the output is acpi_dsdt.c
Usually, user is not expected to change the acpi_dsdt.asl.
In case that the acpi_dsdt.asl need to be updated, please 
Follow the instruction:

# make acpi_dsdt.c