On 10/02/15 11:01, Gerd Hoffmann wrote: > Hi, > >> A solution that I can see is adding DMA boot capabilities to the >> linuxboot.S optionrom. I was trying to avoid this, but it looks like >> not doing so creates lots of problems. It may be better than adding a >> "nice" shortcut somewhere in QEMU or SeaBIOS. >> >> Who uses this optionrom (and will benefit from this change)? > > Any -kernel boot on x86 will use either linuxboot.bin or multiboot.bin.
(Except when your firmware is OVMF -- OVMF has its own LoadLinuxLib. So, if you decide to extend linuxboot.bin / multiboot.bin with the DMA capability, that can't regress OVMF by definition, and you certainly won't hear me complain.) Thanks Laszlo > From a compatibility point of view implementing it in the option rom > certainly has its advantages. And as the option roms are shipped with > and loaded by qemu you don't even have to do runtime detection if that > simplifies things. We can just build two versions of the roms and qemu > can use the one or the other depending on whenever the machine type in > question has fw_cfg dma enabled or not. > > cheers, > Gerd > > > >
