Re: [Qemu-devel] [Qemu-arm] more serial ports on arm?

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi Jason,

On 12/7/18 5:42 AM, Jason A. Donenfeld wrote:
> On Tue, Nov 20, 2018 at 11:08 AM Peter Maydell <peter.maydell@linaro.org> wrote:
>> It's still stuck, because unconditionally adding a second serial
>> port to the virt board breaks some commonly used existing guest
>> code (UEFI + Linux), and it's not clear to me what the best
>> command line UI is for allowing the user to request the second
>> serial port.
> 
> Can the UI be the same more or less as for x86? Specify a second
> -serial, and then the machine gets one added? If it's in secure mode,
> then it's added as serial 3 instead of 2, to remain backwards
> compatible.

You can use various -serial arguments.

If a board supports 4 serials and you only want to see the 3rd (secure
mode as your example) you could use:

./qemu -serial null -serial null -serial stdio

serials #1 and #2 and #4 would be redirected to the null backend, thus
ignored, and you bind the secure serial to your stdio.