[SeaBIOS] [PATCH 2/2] Boot Linux using QEMU fw_cfg DMA interface

[Kevin O'Connor]

On Fri, Aug 07, 2015 at 01:55:17AM +0200, Laszlo Ersek wrote:
> On 08/06/15 17:46, Kevin O'Connor wrote:
> > As an aside - if ultimately the goal is to change QEMU so that it no
> > longer uses linuxboot,
> 
> I don't think that's the ultimate / primary goal (well, certainly not
> the reason why I'm interested in this work).
> 
> > I wonder if it makes sense to clean up the
> > QEMU<->firmware interface for it.  It seems that linuxboot uses 12
> > old-style fw_cfg entries to pass the kernel.  It seems that could be
> > replaced with three new-style fw_cfg "file" entries - "/vmlinuz",
> > "/initrd", and "/cmdline" - and QEMU could avoid having to parse and
> > manipulate the vmlinuz contents.  I'm guessing all the old-style
> > fw_cfg entries were implemented to make the linuxboot assembler
> > easier.  That shouldn't be necessary with SeaBIOS though.  Just
> > something to think about - it shouldn't be a pre-requisite for the
> > fw_cfg dma stuff.
> 
> Both OVMF (UEFI for x86 guests, built from edk2) and AAVMF (UEFI for ARM
> guests, built from edk2) depend on those old-style fw_cfg entries.

Okay, I wasn't aware of that.  I agree it probably isn't worth
changing.

-Kevin