On Tue, May 07, 2013 at 09:00:48PM +0300, Michael S. Tsirkin wrote: > On Thu, Apr 25, 2013 at 12:02:20PM +0300, Michael S. Tsirkin wrote: > > 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. > > After some thought, there are two additional > options worth considering, in that they simplify > bios code somewhat: > > - bios could get size from qemu, allocate a buffer > (e.g. could be one buffer for all tables) > and pass the address to qemu. > qemu does all the patching > > - further, qemu could do the copy of tables into > that address directly
This seems more complex than necessary to me. The important task is to get the tables generated in QEMU - I'd focus on getting the tables generated in QEMU (one table per fw_cfg "file"). Once that is done, the SeaBIOS side can be easily implemented, and we can add any enhancements on top if we feel it is necessary. -Kevin
