Re: QOM

[Philippe Mathieu-Daudé]

Hi Abhijeet,

On 12/21/21 12:27, abhijeet inamdar wrote:
> Hi,
> 
> 1)What does QOM stand for?

QOM: "QEMU Object Model"

See https://qemu-project.gitlab.io/qemu/devel/qom.html

> 2)Can anyone tell what this error means? 
> 
> (qemu) Unexpected error in object_property_find() at
> /home/ocp/vcpu-playground/vcpu_on_qemu/qemu-4.2.0/qom/object.c:1177:
> qemu-system-arm: Property '.sysbus-irq[0]' not found
> Aborted (core dumped).

I suppose you are trying to connect a device gpio/irq output line
to another device input, likely using sysbus_connect_irq().

The API is "connect the N-th output line from the SysBus device
to this qemu_irq handler", where qemu_irq is the input line.

Apparently your SysBus device doesn't have any output line
registered. These are registered using sysbus_init_irq().
The first call register the first output IRQ, and so on.

Some objects have their QOM interface documented, for
example to use the ARM GIC see:
https://gitlab.com/qemu-project/qemu/-/blob/master/include/hw/intc/arm_gic.h#L22

Hope that helps.

Regards,

Phil.