linuxdc-dev — Developer discussion list

Re: [linuxdc-dev]mu Law support - cast your vote

[M. R. B. <mr...@0x...>]

* Adrian McMenamin <ad...@mc...> on Thu, Jan 03, 2002:

> Mu Law support could be added to the sound driver at the cost of a 32k lo=
ok=20
> up table (plus a bit of code to manage it).
>=20

Feeping creaturism.

IMHO you should focus on speeding the driver up.

M> R.

[linuxdc-dev]mu Law support - cast your vote

[Adrian M. <ad...@mc...>]

Mu Law support could be added to the sound driver at the cost of a 32k look 
up table (plus a bit of code to manage it).

What do people think - is muLaw that important or not?

To put it in perspective - userland applications might easily attempt to pass 
a 16k buffer to the sound driver, so on that basis 32k is not too big.

But - this system has only 16M in all... and muLaw is rather uncommon these 
days...

[linuxdc-dev]Re: Programs that run

[Unknown W. <tun...@an...>]

> Just for info...(those of you on IRC will already know this)
> 
> Have successfully run mpg123, madplay (two MP3 players) and epic (IRC client) 
> on the Dreamcast
> 
> 
> So - even more reasobns to get your friends to get a Dreamcast :->

So is there an image ready to be burnt, or is there still of work to do on
our part to get it runnin?

[linuxdc-dev]A general developer question

[Adrian M. <ad...@mc...>]

As this is a developer's list...

What advantages (if any) would I gain as a developer from switching from RH 
to Debian (no theology please) on my linux/intel box.

Why is Debian the "developer's distribution"?

Adrian

Re: [linuxdc-dev]AICA interrupts - problem solved?

[Adrian M. <ad...@mc...>]

On Wednesday 02 Jan 2002 10:42 am, Adrian McMenamin wrote:
> It seems I was calling this incorrectly - the 'pending' bits need to be
> reset inside the interrupt handler as without that happening no new
> interrupts can be handled on the AICA (or something) - this obviously was
> not happening, but when the handler was rewritten:
>
> ////////////////////////////////////////////////////////////////
> // Experimental interrupt handler                             //
> ////////////////////////////////////////////////////////////////
>
> void aica_interrupt_handler(int i, void* p, struct pt_regs * ptr)
> {
> 	writel(0x20, 0xa07028b8);
> 	spu_write_wait();
> }
>
> The problem disappeared (nb - removed the write to 0xa07028b8 from
> elsewhere too).

However, a scan of /proc/interrupts also shows that while the interrupt 
handler is registered, there appear to be no interrupts being generated, so 
this does not seem a suitable vehicle in which handle buffer updates.

Re: [linuxdc-dev]AICA interrupts - problem solved?

[Adrian M. <ad...@mc...>]

It seems I was calling this incorrectly - the 'pending' bits need to be reset 
inside the interrupt handler as without that happening no new interrupts can 
be handled on the AICA (or something) - this obviously was not happening, but 
when the handler was rewritten:

////////////////////////////////////////////////////////////////
// Experimental interrupt handler                             //
////////////////////////////////////////////////////////////////

void aica_interrupt_handler(int i, void* p, struct pt_regs * ptr)
{
	writel(0x20, 0xa07028b8);
	spu_write_wait();  
}

The problem disappeared (nb - removed the write to 0xa07028b8 from elsewhere 
too).

Re: [linuxdc-dev]AICA interrupts

[Adrian M. <ad...@mc...>]

On Tuesday 01 Jan 2002 7:28 pm, Adrian McMenamin wrote:

> Further poking about suggests that this does not happen with every write of
> the 0xa07028b8, but only when something is written to the AICA memory. At
> least the number of "Unexpected IRQ traps..." matches the number of writes.
>
No, this is wrong too - as I have just had a case of three writes and only 
two error messages...

Re: [linuxdc-dev]AICA interrupts

[Adrian M. <ad...@mc...>]

On Tuesday 01 Jan 2002 6:56 pm, M. R. Brown wrote:
>
> Can you check /proc/interrupts to see what interrupts are being handled
> (PVR2, gdrom, BBA, etc.), and attach your dmesg output?
cat /proc/interrupts

	CPU0
16:	422427		IPR_IRQ	timer
53:	253191		System ASIC		pvr2 VBL handler
80:	0		System ASIC		gdrom
81:	658		System ASIC		AICA
83:	2019		System ASIC		eth0

Re: [linuxdc-dev]AICA interrupts

[Adrian M. <ad...@mc...>]

On Tuesday 01 Jan 2002 7:18 pm, M. R. Brown wrote:
> * M. R. Brown <mr...@0x...> on Tue, Jan 01, 2002:
> > * Adrian McMenamin <ad...@mc...> on Tue, Jan 01, 2002:
> > > I am experimenting with the AICA interrupt - HW_EVENT_AICA_SYS - but I
> > > am getting odd results:
> >
> > [...]
> >
> > > When this runs every call to writel(0x20, 0xa07028b8) appears to
> > > generate "unexpected IRQ trap at vector 0b" (though system output
> > > otherwise is normal).
> > >
> > > What have I done wrong?
> >
> > I don't understand why you're getting the "unexpected IRQ ..." message,
> > the DC interrupt-handling code switches off of SH4 IRQ's 9, 11, and 13,
> > so they should always be "expected" and return the virtual IRQ.  See
> > arch/sh/kernel/setup_dc.c::systemasic_irq_demux() for more info.
>
> I added the code you sent in your message.
>
> Hmm, ok, I hit it too, but it's still a bit perplexing since
> /proc/interrupts says AICA interrupts are being triggered;
>
> # cat /proc/interrupts
>            CPU0
>  16:      11594         IPR-IRQ  timer
>  40:          0         IPR-IRQ  sci
>  41:        106         IPR-IRQ  sci
>  42:          0         IPR-IRQ  sci
>  43:        463         IPR-IRQ  sci
>  53:       6933     System ASIC  pvr2 VBL handler
>  81:         32     System ASIC  AICA
>  83:       2597     System ASIC  eth0
>
> But I still get the "unexpected IRQ" messages on playback.
>
> I'm going to dig around the irq and DC irq stuff a bit more, I'll let you
> know when I find out what's going on.
>
> I'm also starting to suspect something a bit more insidious, after catting
> /proc/interrupts a couple of times now I get "Unable to handle kernel
> paging request" register dumps, followed by cat segfaulting.  Something
> looks to be seriously broken.
>
> M. R.


My /proc/interrupts also indicates that AICA interrupts are being handled 
too. I have not had any problems with paging errors.

Further poking about suggests that this does not happen with every write of 
the 0xa07028b8, but only when something is written to the AICA memory. At 
least the number of "Unexpected IRQ traps..." matches the number of writes.

[Interestingly when I removed the enable and disable writes and just kept the 
pending one the whole system froze and could only be restored by switching 
off - not sure why that should be.]

Re: [linuxdc-dev]AICA interrupts

[M. R. B. <mr...@0x...>]

* M. R. Brown <mr...@0x...> on Tue, Jan 01, 2002:

> * Adrian McMenamin <ad...@mc...> on Tue, Jan 01, 2002:
>=20
> > I am experimenting with the AICA interrupt - HW_EVENT_AICA_SYS - but I =
am=20
> > getting odd results:
> >=20
> >=20
> [...]
> > When this runs every call to writel(0x20, 0xa07028b8) appears to genera=
te=20
> > "unexpected IRQ trap at vector 0b" (though system output otherwise is n=
ormal).
> >=20
> > What have I done wrong?
> >=20
>=20
> I don't understand why you're getting the "unexpected IRQ ..." message, t=
he
> DC interrupt-handling code switches off of SH4 IRQ's 9, 11, and 13, so th=
ey
> should always be "expected" and return the virtual IRQ.  See
> arch/sh/kernel/setup_dc.c::systemasic_irq_demux() for more info.
>=20

I added the code you sent in your message.

Hmm, ok, I hit it too, but it's still a bit perplexing since
/proc/interrupts says AICA interrupts are being triggered;

# cat /proc/interrupts                                                     =
                                                                           =
   =20
           CPU0                                                            =
                                                                           =
   =20
 16:      11594         IPR-IRQ  timer                                     =
                                                                           =
   =20
 40:          0         IPR-IRQ  sci                                       =
                                                                           =
   =20
 41:        106         IPR-IRQ  sci                                       =
                                                                           =
   =20
 42:          0         IPR-IRQ  sci                                       =
                                                                           =
   =20
 43:        463         IPR-IRQ  sci                                       =
                                                                           =
   =20
 53:       6933     System ASIC  pvr2 VBL handler                          =
                                                                           =
   =20
 81:         32     System ASIC  AICA                                      =
                                                                           =
   =20
 83:       2597     System ASIC  eth0

But I still get the "unexpected IRQ" messages on playback.

I'm going to dig around the irq and DC irq stuff a bit more, I'll let you
know when I find out what's going on.

I'm also starting to suspect something a bit more insidious, after catting
/proc/interrupts a couple of times now I get "Unable to handle kernel
paging request" register dumps, followed by cat segfaulting.  Something
looks to be seriously broken.

M. R.

Re: [linuxdc-dev]AICA interrupts

[M. R. B. <mr...@0x...>]

* Adrian McMenamin <ad...@mc...> on Tue, Jan 01, 2002:

> I am experimenting with the AICA interrupt - HW_EVENT_AICA_SYS - but I am=
=20
> getting odd results:
>=20
>=20
[...]
> When this runs every call to writel(0x20, 0xa07028b8) appears to generate=
=20
> "unexpected IRQ trap at vector 0b" (though system output otherwise is nor=
mal).
>=20
> What have I done wrong?
>=20

I don't understand why you're getting the "unexpected IRQ ..." message, the
DC interrupt-handling code switches off of SH4 IRQ's 9, 11, and 13, so they
should always be "expected" and return the virtual IRQ.  See
arch/sh/kernel/setup_dc.c::systemasic_irq_demux() for more info.

The only other thing I can think of is that the DC machine vector (machvec)
isn't being selected, and that can only happen if you forget to set the
machine type as "Dreamcast" when configuring the kernel.

Can you check /proc/interrupts to see what interrupts are being handled
(PVR2, gdrom, BBA, etc.), and attach your dmesg output?

M. R.

[linuxdc-dev]AICA interrupts

[Adrian M. <ad...@mc...>]

I am experimenting with the AICA interrupt - HW_EVENT_AICA_SYS - but I am 
getting odd results:

This is the request call:

request_irq(HW_EVENT_AICA_SYS, aica_interrupt_handler, SA_INTERRUPT, "AICA", 
NULL);

And this is the (very simple!) handler:

////////////////////////////////////////////////////////////////
// Experimental interrupt handler                             //
////////////////////////////////////////////////////////////////

void aica_interrupt_handler(int i, void* p, struct pt_regs * ptr)
{
  
}


This is triggered thus:

static ssize_t aica_audio_write(struct file *file, const char *buffer,
				size_t count, loff_t * ppos)
{
	if (count < 1)
		return 0;

	//enable aica interrupts
	writel(0x20, 0xa07028b4);
	spu_write_wait();
	ssize_t ret;
	ret = aica_audio_do_write(file, buffer, count, ppos);
	writel(0x20, 0xa07028b8);
	spu_write_wait();
	//turn off aica interrupts
	writel(0x20, 0xa07028bc);

	spu_write_wait();
	return ret;

}

When this runs every call to writel(0x20, 0xa07028b8) appears to generate 
"unexpected IRQ trap at vector 0b" (though system output otherwise is normal).

What have I done wrong?

Adrian

[linuxdc-dev]Re: [linuxsh-dev] Floating point problems - Dreamcast 2.4.10-pre6 kernel

[Adrian M. <ad...@mc...>]

On Friday 28 Dec 2001 2:54 am, NIIBE Yutaka wrote:
> Adrian McMenamin wrote:
>  > costab[k] = 1.0 / (2.0 * cos( 3.14159265358979323846 * ((double) k * 2.0
>  > + 1.0) / (double) divv));
>
> [...]
>
>  > So: the questions are - is this a known problem, has it been fixed in
>  > later kernels or have I just got it wrong?
>
> I don't know if this is related, we have a FPU bug wrt floating point
> to double conversion.  For example, compiling runtime of Java, GCC
> fails because of exception.
>
> I have experimental fix for this issue, I'll send this to linuxsh-dev
> soon.

Just to close this. I rebuilt my tools and upgraded to gcc 3.0.3 and now the 
programme compiles and runs fine.

Not sure what the problem was exactly - could have been a badly patched 
compiler, could have been a corrupted library - but it works now.

Adrian

[linuxdc-dev]Programs that run

[Adrian M. <ad...@mc...>]

Just for info...(those of you on IRC will already know this)

Have successfully run mpg123, madplay (two MP3 players) and epic (IRC client) 
on the Dreamcast


So - even more reasobns to get your friends to get a Dreamcast :->

Re: [linuxdc-dev]Busybox behaviour

[Adrian M. <ad...@mc...>]

On Monday 31 Dec 2001 6:51 pm, M. R. Brown wrote:
> * Adrian McMenamin <ad...@mc...> on Mon, Dec 31, 2001:
> > I had copied over libc, but then found that there was a dependency on
> > libm. When I copied over all the library files - as per instructions on
> > linuxsh.org I got a different error:
> >
> > "./mpg123: error while loading shared libraries: libm.so.6: cannot open
> > shared object file: No such file or directory"
> >
> > I thought this was a PATH error, but even with PATH pointing to /lib I
> > still have this problem? Is it something to do with the symlinks? The
> > library is there...
>
> s/PATH/LD_LIBRARY_PATH/.
>
Yes, that worked. Thanks, as always.

> M. R.

Re: [linuxdc-dev]Busybox behaviour

[M. R. B. <mr...@0x...>]

* Adrian McMenamin <ad...@mc...> on Mon, Dec 31, 2001:

> I had copied over libc, but then found that there was a dependency on lib=
m.=20
> When I copied over all the library files - as per instructions on linuxsh=
.org=20
> I got a different error:
>=20
> "./mpg123: error while loading shared libraries: libm.so.6: cannot open=
=20
> shared object file: No such file or directory"
>=20
> I thought this was a PATH error, but even with PATH pointing to /lib I st=
ill=20
> have this problem? Is it something to do with the symlinks? The library i=
s=20
> there...
>=20

s/PATH/LD_LIBRARY_PATH/.

M. R.

Re: [linuxdc-dev]Busybox behaviour

[Adrian M. <ad...@mc...>]

On Monday 31 Dec 2001 4:13 pm, M. R. Brown wrote:
> * Adrian McMenamin <ad...@mc...> on Mon, Dec 31, 2001:

> Do you have glibc installed in your NFS root environment?  Is busybox
> statically-linked?

Busybox is statically linked - I couldn't get init to work with it 
dynamically linked.

I had copied over libc, but then found that there was a dependency on libm. 
When I copied over all the library files - as per instructions on linuxsh.org 
I got a different error:

"./mpg123: error while loading shared libraries: libm.so.6: cannot open 
shared object file: No such file or directory"

I thought this was a PATH error, but even with PATH pointing to /lib I still 
have this problem? Is it something to do with the symlinks? The library is 
there...

>
> > I am using ASH as the shell.
> >
> > Finally - another question:
> >
> > On m17n using devfs I could do things like cat somefile > /dev/dsp
> >
> > But bb (again using devfs) insists on me writing cat somefile >
> > /dev/sound/dsp
> >
> > Why?
>
> The first is because the m17n distro created/maintained legacy device nodes
> (/dev/dsp).  You would have to manually create /dev/dsp and others if you
> *didn't* want to use devfs with busybox.
>

Thanks for this.

> M. R.

Re: [linuxdc-dev]Busybox behaviour

[M. R. B. <mr...@0x...>]

* Adrian McMenamin <ad...@mc...> on Mon, Dec 31, 2001:

>=20
> I have successfully mounted busybox as NFS root, but when I attempt to ru=
n=20
> other applications I get messages such as:
>=20
> "./mpg123: No such file or directory"
>=20
> Is this because there is a library missing or is there some other problem=
=20
> with bb I am unaware of?
>

Do you have glibc installed in your NFS root environment?  Is busybox
statically-linked?

> I am using ASH as the shell.
>=20
> Finally - another question:
>=20
> On m17n using devfs I could do things like cat somefile > /dev/dsp
>=20
> But bb (again using devfs) insists on me writing cat somefile > /dev/soun=
d/dsp
>=20
> Why?
>=20

The first is because the m17n distro created/maintained legacy device nodes
(/dev/dsp).  You would have to manually create /dev/dsp and others if you
*didn't* want to use devfs with busybox.

M. R.

[linuxdc-dev]Busybox behaviour

[Adrian M. <ad...@mc...>]

I know this isn't really likely to have much to do with the LinuxDC kernel, 
but someone here might know the answer...

I was using the m17n distro as my NFS mounted file system for the DC, but I 
had real problems running programs I had compiled, so I dumped that, rebuilt 
my toolset and went back to using busybox.

I have successfully mounted busybox as NFS root, but when I attempt to run 
other applications I get messages such as:

"./mpg123: No such file or directory"

Is this because there is a library missing or is there some other problem 
with bb I am unaware of?

I am using ASH as the shell.

Finally - another question:

On m17n using devfs I could do things like cat somefile > /dev/dsp

But bb (again using devfs) insists on me writing cat somefile > /dev/sound/dsp

Why?

On m17n

[linuxdc-dev][linuxsh-dev] Floating point problems - Dreamcast 2.4.10-pre6 kernel

[NIIBE Y. <gn...@m1...>]

Adrian McMenamin wrote:
 > costab[k] = 1.0 / (2.0 * cos( 3.14159265358979323846 * ((double) k * 2.0 + 
 > 1.0) / (double) divv));
[...]
 > So: the questions are - is this a known problem, has it been fixed in later 
 > kernels or have I just got it wrong?

I don't know if this is related, we have a FPU bug wrt floating point
to double conversion.  For example, compiling runtime of Java, GCC
fails because of exception.

I have experimental fix for this issue, I'll send this to linuxsh-dev
soon.
-- 

Re: [linuxdc-dev]Sound driver

[Oliver M . B. <ol...@go...>]

Hi!

On Thu, Dec 27, 2001 at 11:36:48AM +0000, Adrian McMenamin <ad...@mc...> wrote...
> I know it's Christmas and all that ... but I've had no feedback on this 
> whatsoever, does that mean it all works for people or that it doesn't or that 
> nobody has tried :->

I have been just lazy and away from my DC. The possibility of sound
is really great news as I always wanted to let my DC spend it's
afterlife as an MP3 juke-box.
 
> If anybody has had difficulties becuase they are not sure how to build it 
> then let me know and I'll write a mini HOWTO if that would help.

How about putting an working kernel image somewhere. This way, people
could easily boot it using eCos/RedBoot or whatever.
After all, we have the fortune to all own exactly identical hardware.

-- 
	Oliver M. Bolzer
	ol...@go...

GPG (PGP) Fingerprint = 621B 52F6 2AC1 36DB 8761  018F 8786 87AD EF50 D1FF

Re: [linuxdc-dev]Floating point problems - Dreamcast 2.4.10-pre6 kernel

[M. R. B. <mr...@0x...>]

* Adrian McMenamin <ad...@mc...> on Thu, Dec 27, 2001:

> I have been working to make/port a decent mp3 player for the Dreamcast no=
w=20
> that there is a sound driver.
>=20
> I have built mpg123 with these options:
>=20
> dream:
> 	$(MAKE) CC=3Dsh4-linux-gcc LDFLAGS=3D \
> 	OBJECTS=3D'decode.o dct64.o audio_oss.o' \
> 	CFLAGS=3D'-DREAL_IS_FLOAT -DLINUX -Wall -O2 \
> 		-DOSS \
> 		-fomit-frame-pointer -funroll-all-loops \
> 		-finline-functions -ffast-math' \
> 		mpg123-make
>

Update: Using the above line in mpg123/Makefile (with dream changed to
linux-sh for consistency), I built mpg123 and executed it on the Dreamcast =
...
no problems whatsoever.

You must have a snag in your toolchain somewhere.  I'm using (all patched
with the latest patchset from ftp.m17n.org/pub/super-h/testing/) binutils
2.11.2, GCC 3.0.3, and glibc 2.2.4.  This was executed under the busybox
shell (the sh-like one) under kernel 2.4.16.

M. R.

Re: [linuxdc-dev]Sound driver

[Jay C. <no...@no...>]

On Thursday, December 27, 2001, at 12:52 PM, Jason Dodson wrote:

> Im lazy. I will try it, as I evetually want to see if I can get Bochs
> running some old DOS games. But like I said, Im lazy. As soon as I give 
> it a
> spin, Ill let you know.

You may want to try MESS as well.  MESS tries hard to get timing right; 
I had problems getting Kroz to run at reasonable speeds on Bochs.  Also, 
the versions of Bochs I was playing with (1.2 and 1.3) had terrible 
problems with OpenDOS and FreeDOS---in particular, after touching a 
floppy drive, the disk suddenly appeared blank.

Jay

Re: [linuxdc-dev]Floating point problems - Dreamcast 2.4.10-pre6 kernel

[M. R. B. <mr...@0x...>]

* Adrian McMenamin <ad...@mc...> on Thu, Dec 27, 2001:

> I have been working to make/port a decent mp3 player for the Dreamcast no=
w=20
> that there is a sound driver.
>=20
> I have built mpg123 with these options:
>=20
> dream:
> 	$(MAKE) CC=3Dsh4-linux-gcc LDFLAGS=3D \
> 	OBJECTS=3D'decode.o dct64.o audio_oss.o' \
> 	CFLAGS=3D'-DREAL_IS_FLOAT -DLINUX -Wall -O2 \
> 		-DOSS \
> 		-fomit-frame-pointer -funroll-all-loops \
> 		-finline-functions -ffast-math' \
> 		mpg123-make
>=20
> but this always generates a floating point exception at run time.
>=20

I'm not to keen on how the flags function for the SH backend of GCC (maybe
NIIBE-san knows?) but I always thought -ffast-math was a i386-based (not
necessarily specific) optimization.  I don't think it's wise to use it here
=2E.. although it may be a no-op.  Only a read through GCC's source will
confirm that.

>=20
> Incuidentally with -DREAL_IS_FLOAT switched off then there is no fp excep=
tion=20
> but the program outputs static.
>=20

Have you tried with -m4-single-only?  It generates FP code conforming to
what its name implies.

> So: the questions are - is this a known problem, has it been fixed in lat=
er=20
> kernels or have I just got it wrong?
>=20

I don't see how it could be a kernel issue.

M. R.

Re: [linuxdc-dev]Sound driver

[Jason D. <min...@ya...>]

Im lazy. I will try it, as I evetually want to see if I can get Bochs
running some old DOS games. But like I said, Im lazy. As soon as I give it a
spin, Ill let you know.

----- Original Message -----
From: "Adrian McMenamin" <ad...@mc...>
To: <lin...@li...>
Sent: Thursday, December 27, 2001 6:36 AM
Subject: [linuxdc-dev]Sound driver


> I know it's Christmas and all that ... but I've had no feedback on this
> whatsoever, does that mean it all works for people or that it doesn't or
that
> nobody has tried :->
>
> Any comments would be welcome.
>
> If anybody has had difficulties becuase they are not sure how to build it
> then let me know and I'll write a mini HOWTO if that would help.
>
> Adrian
>
> _______________________________________________
> Linuxdc-dev mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxdc-dev


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