Re: [Qemu-devel] [PATCH v4] Add optionrom compatible with fw_cfg DMA version

["Marc Marí" <marc.mari.barcelo@gmail.com>]

El Tue, 02 Feb 2016 13:04:55 +0100
Gerd Hoffmann <kraxel@redhat.com> escribió:
> On Di, 2016-02-02 at 12:06 +0100, Gerd Hoffmann wrote:
> >   Hi,
> > 
> > >  %.img: %.o
> > > -	$(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e
> > > _start -s -o $@ $<,"  Building $(TARGET_DIR)$@")
> > > +	$(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m elf_i386
> > > -Ttext 0 -e _start -s -o $@ $<,"  Building $(TARGET_DIR)$@")
> > 
> > Hmm, that breaks the windows cross build:
> > 
> > make: Entering directory `/home/kraxel/projects/qemu/build-win32'
> >   Building optionrom/linuxboot_dma.img
> > i686-w64-mingw32-ld: unrecognised emulation mode: elf_i386
> > Supported emulations: i386pe
> > make[1]: *** [linuxboot_dma.img] Error 1
> 
> Testing shows two more problems:
> 
> (1) initrd loading is broken, kernel complains it finds only
> gibberish:
> 
> [    0.934582] Unpacking initramfs...
> [    1.166983] Initramfs unpacking failed: junk in compressed archive
> [    1.168458] Freeing initrd memory: 32812k freed

Will look at it. It is probably being copied to a wrong location.

> (2) going back to non-dma boot via -M pc-$old doesn't work,
> appearently fw_cfg dma is enabled even for old machine types.

I don't remember discussing the topic of machine types when touching
fw_cfg DMA. Which means, it probably slipped amongst the other details.
But it is now merged and in stable, so it should probably be left as it
is now.

Should this optionrom be enabled only with the latest machine type?

Thanks
Marc