[Qemu-devel] New display device for MIPS

[Qemu-devel] New display device for MIPS

[Stefan Weil]

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Hi,

the latest Linux kernels contain a driver for an ASCII display
(arch/mips/mips-boards/generic/display.c).

Because this display is used by code I'm currently testing,
I implemented an emulation for QEMU (code is added to this mail).

hw/mips_display.c   - implementation
hw/mips_display.h   - interface

I prefer to have the interface in a dedicated header file instead
of adding it to vl.h (which is already overloaded).

An emulated MIPS machine can add the new device like this:

...
#include "mips_display.h"
...
mips_display_init(env, "vc");
...

Regards

Stefan Weil




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Re: [Qemu-devel] New display device for MIPS

[Thiemo Seufer]

Stefan Weil wrote:
> Hi,
> 
> the latest Linux kernels contain a driver for an ASCII display
> (arch/mips/mips-boards/generic/display.c).

This is the driver for the ASCII display of a MIPS MALTA board.

> Because this display is used by code I'm currently testing,
> I implemented an emulation for QEMU (code is added to this mail).
> 
> hw/mips_display.c   - implementation
> hw/mips_display.h   - interface

AFAICS the output interferes with the serial console output.
I wonder how the typical scrolling text "Linux on MALTA" would look
like in that case. :-)

> I prefer to have the interface in a dedicated header file instead
> of adding it to vl.h (which is already overloaded).

OTOH, a file for a single prototype which still has to include vl.h
makes not much sense either.


Thiemo

Re: [Qemu-devel] New display device for MIPS

[Stefan Weil]

> AFAICS the output interferes with the serial console output.
> I wonder how the typical scrolling text "Linux on MALTA" would look
> like in that case. :-)
>
Believe me, it won't interfere (because it creates an additional
virtual console, like 2nd serial console, parallel port, ...).

And you will see the typical scrolling text, just try it!

Stefan

Re: [Qemu-devel] New display device for MIPS

[Thiemo Seufer]

Stefan Weil wrote:
> 
> > AFAICS the output interferes with the serial console output.
> > I wonder how the typical scrolling text "Linux on MALTA" would look
> > like in that case. :-)
> >
> Believe me, it won't interfere (because it creates an additional
> virtual console, like 2nd serial console, parallel port, ...).
> 
> And you will see the typical scrolling text, just try it!

Trying would be much easier if there was a machine to test with. :-)
What about starting with the core of the new machine description before
submitting the unconnected peripherals?


Thiemo

Re: [Qemu-devel] New display device for MIPS

[Alexander Voropay]

"Thiemo Seufer" <ths@networkno.de> wrote:

>> > AFAICS the output interferes with the serial console output.
>> > I wonder how the typical scrolling text "Linux on MALTA" would look
>> > like in that case. :-)
> What about starting with the core of the new machine description before
> submitting the unconnected peripherals?

 The Malta-LED is a part of the Malta-FPGA device wich also contains
- DIP-Switch block, including BIGEND switch
- NMI status register
- Software reset
- GPIO registers
- I2C registers

 Is should be better to implement all this devices as one "Malta FPGA" driver.


P.S. AFAIK, Virtio VPMM emulates Malta LED in the separate graphic
window, not on the serial port.

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