The machine is based on Goldfish interfaces defined by Google
for Android simulator. It uses Goldfish-rtc (timer and RTC),
Goldfish-pic (PIC) and Goldfish-tty (for serial port and early tty).

The machine is created with 128 virtio-mmio bus, and they can
be used to use serial console, GPU, disk, NIC, HID, ...

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210312214145.2936082-6-laurent@vivier.eu>