Am 18.04.2013 um 09:32 schrieb Pranavkumar Sawargaonkar <[email protected]>:
> On 18 April 2013 12:21, Rusty Russell <[email protected]> wrote: >> >> PranavkumarSawargaonkar <[email protected]> writes: >>> From: Pranavkumar Sawargaonkar <[email protected]> >>> >>> This patch implements early printk support for virtio-mmio console devices >>> without using any hypercalls. >> >> This makes some sense, though not sure that early console *read* makes >> much sense. I can see the PCI version of this being useful as well. > > Read can be useful for "mach-virt" which will have only virtio console > as a console device. Then if someone wants to have UEFI or any other > boot-loader emulation, which expects user to input few things, in that > case read might become handy. A boot loader should easily be able to implement virtio-console for real. In fact, you should be able to do a simple virtio-console implementation for early printk too, that polls the host for acks rather than use interrupts. Check out my s390-zipl code for reference. I use that there. The advantage to that would be that no host changes are required whatsoever and the interface strictly stays as it is. Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
