On 22/05/2015 18:54, Saket Sinha wrote:
Hi Simon,
Is it possible for us to add support to qemu to provide acpi tables via fw_cfg in u-boot ?
If we find acpi tables in fw_cfg try loading them, otherwise fallback to the builtin acpi tables.
Coreboot does it in the following way - http://review.coreboot.org/#/c/4040/
It seems like it might be useful to implement this in U-Boot. Perhaps look at this after you have the built-in support running?
I guess it would be extremely useful for u-boot.
It is being used by q-boot, a new minimal x86 firmware for QEMU. http://lwn.net/Articles/645455/ https://github.com/bonzini/qboot
q-boot is able to give a minimal booting time, with the help of fw_cfg, by reading both the kernel and initrd image from fw_cfg. I guess ACPI support for both q-boot and qemu-x86 in u-boot can be implemented on similar lines.
ACPI support is now included in qboot.
Paolo