On Wed, 19 Aug 2015 00:27:54 +0200 Gerd Hoffmann kraxel@redhat.com wrote:
On Di, 2015-07-21 at 18:06 +0200, Marc Marí wrote:
It's probably not good to override all the ROM options. Better ways can be discussed.
source code for the option rom doing linux kernel (and multiboot kernel) boot is in pc-bios/optionrom/ (qemu tree). Patching that one to use fw_cfg dma if available should get simliar speedups, but without compatiblity issues.
The problem with patching the current ROMs, is that they are written in assembly. So they would need a complete rewrite in C. Writing a DMA guest in assembly I think it is a nightmare (but it can be done, of course).
But it is true that I overlooked that point. I might get into this change in the future.
Thanks Marc