On Tue, Nov 03, 2015 at 09:44:52AM -0800, Mario Smarduch wrote: > On 11/3/2015 8:33 AM, Christopher Covington wrote: > > On 11/02/2015 06:51 PM, Mario Smarduch wrote: > >> this is a re-post from couple weeks ago, please take time to review this > >> simple patch which simplifies DEBUG_LL and prevents kernel crash on virtual > >> platforms. > >> > >> Before this patch DEBUG_LL for 'dummy virtual machine': > >> > >> ( ) Kernel low-level debugging via EmbeddedICE DCC channel > >> ( ) Kernel low-level debug output via semihosting I/O > >> ( ) Kernel low-level debugging via 8250 UART > >> ( ) Kernel low-level debugging via ARM Ltd PL01x Primecell > >> > >> In summary if debug uart is not emulated kernel crashes. > >> And once you pass that hurdle, uart physical/virtual addresses are unknown. > >> DEBUG_LL comes in handy on many occasions and should be somewhat > >> intuitive to use like it is for physical platforms. For virtual platforms > >> user may start daubting the host and get into a bigger mess. > >> > >> After this patch is applied user gets: > >> > >> (X) Kernel low-level debugging on QEMU Virtual Platform > >> ( ) Kernel low-level debugging on Kvmtool Virtual Platform > >> ..... above repeated .... > >> > >> The virtual addresses selected follow arm reference models, high in vmalloc > >> section with high mem enabled and guest running with >= 1GB of memory. The > >> offset is leftover from arm reference models. > > > > Which model? It doesn't appear to match the vexpress AEM/RTSM/FVP/whatever > > which used 0x1c090000 for UART0. > > I recall QEMU virt model had it's own physical address map, for sure I saw the > virtio-mmio regions assigned in some ARM document. Peter would you know? > > As far as kvmtool I'm not sure, currently PC1 COM1 port is used? Andre will that > stay fixed? We make absolutely no guarantees about the memory map provided by kvmtool. Will -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
