Re: Framebuffer in OpenBSD

[Markus Ritzer]

Hi!

I'm still working on my framebuffer driver for the Xbox.

Now I know that I just have to map 4MB of memory and access it, but I don't 
know how to implement this in a good way.


A few lines from my driver (that doesn't show anything on the the until now):

struct xboxfb_softc {
struct device sc_dev;
bus_space_tag_t tag;
bus_space_handle_t handle;
};


void xboxfb_attach(struct device * parent, struct device * self, void * aux) {
struct xboxfb_softc *sc = (struct xboxfb_softc *) self;
struct pci_attach_args *pa = aux;
int ret;

sc-tag = pa-pa_memt;
ret = bus_space_map(sc-tag, XBOX_RAM_SIZE - XBOX_FB_SIZE, 
XBOX_FB_SIZE, 2, sc-handle);

  for (i = 0; i  1; i++)
  bus_space_write_4(sc-tag,sc-handle,i,XBOX_FB_BLUE);

}

What do I have to pass to bus_space_map as 4th argument? According to the 
manpage, BUS_SPACE_MAP_LINEAR would be right, but that doesn't seem to exist 
on i386. I tried the value 2 (this is the value on other architectures).


Do I have to take pa_memt or pa_iot (as a tag from the bus) ?


How large is the memory area of a handle?

Does bus_space_vaddr exist on i386? According to the manpage, this could be 
useful for me.


A part of my kernel config:
xboxfb0 at pci? dev ? function ?
wsdisplay*  at xboxfb? console ?

This is from NetBSD.



Best Regards,

Markus

Re: Framebuffer in OpenBSD

[Alexander Yurchenko]

On Tue, Jan 23, 2007 at 12:07:50PM +0100, Markus Ritzer wrote:
 Hello!
 
 I would like to port OpenBSD to the MS Xbox (old one). The Kernel already 
 boots until main() in kern/init_main.c . (I can control this with the front 
 LED of the Xbox). The next thing I would like to do is to write  a kind of 
 framebuffer driver so that I can get output on the TV. I have the sourcecode 
 for the framebuffer driver of FreeBSD and Linux, but I don't know how to 
 integrate it in OpenBSD.
 
 I read that OpenBSD has no framebuffer at all.

openbsd has a lot of framebuffers. look at arch/sparc64/dev/fb.c as a
start.

 
 
 How could I get output from the Kernel?
 
 
 The Xbox has no serial port... just USB and Ethernet.
 
 
 
 Markus Ritzer

-- 
   Alexander Yurchenko

Re: Framebuffer in OpenBSD

[Miod Vallat]

I would like to port OpenBSD to the MS Xbox (old one). The Kernel already
boots until main() in kern/init_main.c . (I can control this with the front
LED of the Xbox). The next thing I would like to do is to write  a kind of
framebuffer driver so that I can get output on the TV. I have the sourcecode
for the framebuffer driver of FreeBSD and Linux, but I don't know how to
integrate it in OpenBSD.


You might to have a look at NetBSD which recently got some xbox support
(although I don't see the point on running on such a machine).


I read that OpenBSD has no framebuffer at all.


This is a overbroad generalization of ``the i386 and amd64 ports of OpenBSD
run the frame buffer in text mode''.

Actually, -CURRENT has code to drive the main display in graphics mode if it
is VESA 2 compliant (vesafb). You might want to build on top of it as well.

Miod