On Thu, 18 Jul 2013, Russell King - ARM Linux wrote: > On Thu, Jul 18, 2013 at 05:43:37PM +0100, Julien Grall wrote: > > When Xen will boot, it will use one UART, given by the user, to be able > > to log its information. Xen will not map the UART region and the IRQ to > > dom0. Of course it will not be present in the device tree either. So if > > Linux tries to access to this memory region, it will crash. > > > > When Linux will boot as dom0, it will either use an hvc console or > > another UART. > > > > In case of multi-platform environments, there is no issue because when > > CONFIG_DEBUG_UNCOMPRESS is disabled. > > > > Now, in non-multiplatform environment, the decompressor will use a > > pre-defined UART. This UART may be already used by Xen and Linux will > > abort at the first access. > > > > I think, the decompressor should be able to detect if the UART exists > > (I'm not sure it's possible) or disabled at compile time uncompress log. > > > > Do you have any better ideas? > > Let me get this straight. > > 1. You want to run an _existing_ platforms kernel under Xen, where the > platform assumes that it has various devices at various locations, > and will make direct accesses to those devices. > > 2. You don't want to provide some of those devices, and you arrange for > those unprovided devices to fault. > > Excuse me if I think that's really silly.
Unfortunately not all the platforms are available on multiplatform kernels. Also by the same argument, we wouldn't need device tree on non-multiplatform kernels because we could hardcode almost anything. > Lastly, aren't all ARMv7 kernels (therefore Xen supporting kernels) > supposed to be part of the multiplatform kernel stuff now? Most of them, yes. However some of them, like exynos5250, are not yet. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
