On 02/27/13 10:19, Gerd Hoffmann wrote: > On 02/26/13 19:30, Laszlo Ersek wrote: >> On 02/26/13 10:03, Gerd Hoffmann wrote: >> >>> Can tianocore grab acpi tables from coreboot? >> >> Not that I know of. (... It may have been a rhetorical question.) > > Wasn't rhetorical. Generating the apci tables in both ovmf and seabios > doesn't make that much sense, better would be to have that in one place. > > Option one is to let qemu provide them, then both ovmf and seabios can > grab them via fw_cfg. > > Option two is to use coreboot underneath, then let both seabios and ovmf > grab the tables from coreboot. Which of course requires that ovmf can > use the tables provided by coreboot. Seabios can do that today. > > /me looked around a bit in the coreboot source code. Looks like they > simply copyed over the dsdt from seabios as-is, which doesn't fly due to > the pci _crs method referencing ssdt's BDAT. > > From the quick look it seems they do *not* generate the dsdt > dynamically, only the other tables (simliar to seabios). So switching > to coreboot probably doesn't help to remove the dsdt patching code we > have in seabios. > >> When running on Xen, an area is searched for the RSDP, and linked tables >> (prepared by Xen's hvmloader I think) are installed by OVMF. > > Ok, so doing something simliar when running on coreboot should be > possible without major headache. > >> When running on qemu, static tables are used. I strived to adapt them as >> much as I could to qemu hardware. Some tables (recognized by header) are >> copied & modified dynamically before installation: MADT, SSDT. > >> Getting a precise picture of qemu hardware in the form of ACPI tables >> (over fw_cfg) would not only allow OVMF to pass on better tables to >> OSPM; OVMF could *maybe* use them itself. > > qemu 1.4+ places the dsdt into fw_cfg. But again, that is the one which > references BDAT, so using it as-is in ovmf isn't going to fly ...
As far as I understood Kevin suggested to - remove the BDAT (FWDT in OVMF) and the related DSDT logic, - prepare the byte-code of the CRS dynamically from a template (t could be a Name instead of a Method) and patch the ranges before installation. Laszlo _______________________________________________ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
