[Arm-netbook] serial console in new kernel sources

[Alejandro Mery]

On Sat, May 19, 2012 at 2:31 PM, David Given <dg at cowlark.com> wrote:
> On 19/05/12 00:45, Henrik Nordström wrote:
> [...]
>>> Apparently it doesn't show up in the kernel configuration tool, and is
>>> selected automatically when you enable generic 8250 support. *shrug*
>>
>> Right. And as it should.
>
> Of course!
>
> Unfortunately... when I turn the driver on, my kernel panics on startup.
>
> [    0.540000] Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled
> [    0.560000] serial8250.0: ttyS0 at MMIO 0x1c28000 (irq = 1) is a
> U6_16550A
> [    0.570000] console [ttyS0] enabled
> [    0.580000] [uart]: used uart info.: 0x05
> [    0.600000] sunxi-uart.0: ttyS0 at MMIO 0x1c28000 (irq = 1) is a
> U6_16550A
> [    0.610000] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000c
>
> Backing out my memory hack makes no difference, and everything appears
> to work fine with the serial driver disabled. The relevant stanza from
> my kernel.conf looks like this:
>
> CONFIG_SERIAL_8250=y
> CONFIG_SERIAL_8250_CONSOLE=y
> CONFIG_SERIAL_8250_SUNXI=y
> CONFIG_SERIAL_8250_NR_UARTS=1
> CONFIG_SERIAL_8250_RUNTIME_UARTS=1
> # CONFIG_SERIAL_8250_EXTENDED is not set
> ...
> CONFIG_SERIAL_CORE=y
> CONFIG_SERIAL_CORE_CONSOLE=y
>
> I'm just building a vanilla kernel now, in case there's something wrong
> with my kernel.conf, but that'll take hours (cross compilation is for
> the weak). Is there anything obvious in the above I'm getting wrong?

can you try using sun4i_defconfig as starting point?