On Fri, Oct 16, 2015 at 08:19:59PM -0700, Mario Smarduch wrote: > When booting a VM using QEMU or Kvmtool there are no clear ways to > enable low level debugging for these virtual platforms. some menu port > choices are not supported by the virtual platforms at all. And there is no > help on the location of physical and virtual addresses for the ports. > This may lead to wrong debug port and a frozen VM with a blank screen. > > This patch adds menu selections for QEMU and Kvmtool virtual platforms for low > level kernel print debugging. Help section displays port physical and > virutal addresses. > > ARM reference models use the MIDR register to run-time select UART port address > (for ARCH_VEXPRESS) based on A9 or A15 part numbers. Looked for a same approach > but couldn't find a way to differentiate between virtual platforms, something > like a platform register. > > Signed-off-by: Mario Smarduch <m.smarduch@xxxxxxxxxxx> > --- I can't think of any better way to do this and I would be happy to see this functionality in Linux, so: Acked-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> > arch/arm/Kconfig.debug | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug > index a2e16f9..d126bd4 100644 > --- a/arch/arm/Kconfig.debug > +++ b/arch/arm/Kconfig.debug > @@ -1155,6 +1155,28 @@ choice > This option selects UART0 on VIA/Wondermedia System-on-a-chip > devices, including VT8500, WM8505, WM8650 and WM8850. > > + config DEBUG_VIRT_UART_QEMU > + bool "Kernel low-level debugging on QEMU Virtual Platform" > + depends on ARCH_VIRT > + select DEBUG_UART_PL01X > + help > + Say Y here if you want the debug print routines to direct > + their output to PL011 UART port on QEMU Virtual Platform. > + Appropriate address values are: > + PHYS VIRT > + 0x9000000 0xf8090000 > + > + config DEBUG_VIRT_UART_KVMTOOL > + bool "Kernel low-level debugging on Kvmtool Virtual Platform" > + depends on ARCH_VIRT > + select DEBUG_UART_8250 > + help > + Say Y here if you want the debug print routines to direct > + their output to 8250 UART port on Kvmtool Virtual > + Platform. Appropriate address values are: > + PHYS VIRT > + 0x3f8 0xf80903f8 > + > config DEBUG_ICEDCC > bool "Kernel low-level debugging via EmbeddedICE DCC channel" > help > -- > 1.9.1 > -- 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
