[SeaBIOS] [PATCH RFC 0/3] seabios: move acpi table formatting out of bios

Michael S. Tsirkin mst at redhat.com
Thu Apr 25 11:02:20 CEST 2013

Untested yet, but I thought I'd share the
BIOS bits so we can agree on direction.

In particular check out ROM sizes:
- Before patchset with DSDT enabled
    Total size: 127880  Fixed: 59060  Free: 3192 (used 97.6% of 128KiB rom)
- Before patchset with DSDT disabled
    Total size: 122844  Fixed: 58884  Free: 8228 (used 93.7% of 128KiB rom)
- After patchset:
    Total size: 128776  Fixed: 59100  Free: 2296 (used 98.2% of 128KiB rom)
- Legacy disabled at build time:
    Total size: 119836  Fixed: 58996  Free: 11236 (used 91.4% of 128KiB rom)

As can be seen from this, most size savings come
from dropping DSDT, but we do save a bit by removing
other tables. Of course the real reason to move tables to QEMU
is so that ACPI can better match hardware.

This patchset adds an option to move all code for formatting acpi tables
out of BIOS. With this, QEMU has full control over the table layout.
All tables are loaded from the new "/etc/acpi/" directory.
Any entries in this directory cause BIOS to disable
ACPI table generation completely.
A generic linker script, controlled by QEMU, is
loaded from "/etc/linker-script". It is used to
patch in table pointers and checksums.

BIOS still has limited ability to parse the tables,
for the following purposes:
	- locate resume vector
	- allocate RSDP in FSEG
	- allocate FACS at an aligned address


Michael S. Tsirkin (3):
  linker: utility to patch in-memory ROM files
  acpi: load and link tables from /etc/acpi/
  acpi: add an option to disable builtin tables

 Makefile     |  2 +-
 src/Kconfig  | 12 +++++++-
 src/acpi.c   | 67 +++++++++++++++++++++++++++++++++++++++++++-
 src/linker.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/linker.h | 50 +++++++++++++++++++++++++++++++++
 src/util.h   |  1 +
 6 files changed, 219 insertions(+), 3 deletions(-)
 create mode 100644 src/linker.c
 create mode 100644 src/linker.h


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