Re: GPIO emulation in QEMU RISCV

[Daniel Henrique Barboza]

On 9/19/23 10:23, Sivachandran S wrote:
> Hi Daniel,
>
> We are working to generate device interrupts via GPIO.But the problem here is 
> by default the QEMU doesn't have any GPIO device emulated. (QEMU 8.0.0)
>
> 1. How to emulate the VIRT GPIO device or any other GPIO device in QEMU? The 
> device models listed in QEMU don't have any of the GPIO devices listed. Any 
> idea how to enable any of the GPIO device emulation in QEMU RISCV?

The Si-Five boards (sifive_e.c, sifive_u.c) uses the Si-Five GPIO device. In
sifive_u.c the device is create here:


static void sifive_u_soc_instance_init(Object *obj)
{
(...)
    object_initialize_child(obj, "gpio", &s->gpio, TYPE_SIFIVE_GPIO);
}


The device itself is implemented in hw/gpio/sifive_gpio.c. In this file it 
mentions
that the Si-Five GPIO device was based on another GPIO device implemented in
hw/gpio/nrf51_gpio.c, which in turn is based on this reference manual:

http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.pdf



Thanks,

Daniel



> 2. Also whether a software patch is required for the QEMU to enable it? If so, 
> please point to it.
>
> Thanks,
> SIva.S