On Thu, Jan 24, 2019 at 11:59:43AM +0000, Andre Przywara wrote: > On Thu, 24 Jan 2019 11:16:29 +0000 > Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote: > > > A warning is displayed if uart0_base is different from what the code > > expects qemu to generate for the pl011 UART in the device tree. > > However, now we support the ns16550a UART emulated by kvmtool, which > > has a different address. This leads to the warning being displayed > > even though the UART is configured and working as expected. > > > > Now that we support multiple UARTs, the warning serves no purpose, so > > remove it. > > Mmh, but we use that address before, right? So for anything not > emulating an UART at this QEMU specific address we write to some random > (device) memory? > > Drew, how important is this early print feature for kvm-unit-tests? The setup code passes through quite a few asserts before getting through io_init() (including in uart0_init), so I think there's still value in having a guessed UART address. Maybe we can provide guesses for both QEMU and kvmtool, and some selection method, that would be used until we've properly assigned uart0_base from DT? > > Cheers, > Andre. > > > > > Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> > > --- > > lib/arm/io.c | 6 ------ > > 1 file changed, 6 deletions(-) > > > > diff --git a/lib/arm/io.c b/lib/arm/io.c > > index 35fc05aeb4db..87435150f73e 100644 > > --- a/lib/arm/io.c > > +++ b/lib/arm/io.c > > @@ -61,12 +61,6 @@ static void uart0_init(void) > > } > > > > uart0_base = ioremap(base.addr, base.size); > > - > > - if (uart0_base != (u8 *)UART_EARLY_BASE) { > > - printf("WARNING: early print support may not work. " > > - "Found uart at %p, but early base is %p.\n", > > - uart0_base, (u8 *)UART_EARLY_BASE); > > - } > > } This warning is doing what it should, which is pointing out that the UART_EARLY_BASE guess appears to be wrong. If we can provide a way to support more than one guess, then we should keep this warning but adjust it to match one of any of the guesses. Thanks, drew