Subject: Fun with 7500FE STB

From: Randolph Chung <[email-masked]>
Date: Sat, 13 Nov 1999 19:41:08 -0700

Hi all,

Hope these questions don't sound too naive. I just got on this list yesterday.

A few of us recently acquired some donated settop boxes (Uniview 210, see
www.uniview.com) that uses a 7500FE CPU. We are interested in getting Linux
on it.

I've been trying to get one of the stock RiscPC kernels to boot on the box,
with no luck. I am not too surprised by this, but would like some pointers
as to how one can start getting such a system to boot.

This is what happens now, when I try to boot a kernel (RiscPC kernel from
www.arm.linux.org, one that I compile myself from netwinder.org's CVS, etc):
I boot with:
!Linux -bootkernel kernel
At the "extra args" prompt, I put "console=ttyS0,9600"

What seems to happen is that the loader loads in the image, and then gives
me a screen full of colorful pixels, and then reboots. I don't see anything
on the other side of the serial port (Connected to my PC).

It is worth noting that the STB has only TV tuner output. In my case, I hook
it up to a tuner card on my PC. 

I have some documentation for the machine, and the 7500FE specs are
available publicly on Cirrus logic's website. Any pointers on how to proceed
is much appreciated.

randolph
tausq@{debian.org,netwinder.org}
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From: Russell King - ARM Linux Admin <[email-masked]>
Date: Sun, 14 Nov 1999 12:34:51 +0000 (GMT)

> Hope these questions don't sound too naive. I just got on this list yesterday.

Please subscribe to linux-arm-kernel as well.  l-a-k is the correct forum for
these discussions now.

> on the other side of the serial port (Connected to my PC).

The "colorful pixels" is a known problem.  Since there is no VRAM, my guess is
that the VIDC is fetching it's display from the first few pages of memory, which
is where the Linux kernel sits.  This is therefore nothing to worry about.  The
only thing I can think of getting aroud this problem is for !Linux to reprogram
the palette with black, ie, no video output until the kernel boots.

I know that you have been talking to me indirectly through Chris Rutter, and
obviously this email means that it seems to be unidirectional. ;(  As a general
note, I don't like talking through people; mistakes happen.  It's better to
get first-hand info.

What I suggest is hooking up another machine to the serial port, and applying
the suggestion I made on l-a-k this month.  (Search for CONFIG_DEBUG_LL).
See the archives on

  ftp.arm.linux.org.uk/pub/armlinux/lists/linux-arm-kernel
   _____
  |_____| ------------------------------------------------- ---+---+-
  |   |        Russell King       [email-masked]      --- ---
  | | | |  http://www.arm.linux.org.uk/~rmk/armlinux.html    /  /  |
  | +-+-+                                                     --- -+-
  /   |               THE developer of ARM Linux              |+| /|\
 /  | | |                                                     ---  |
    +-+-+ -------------------------------------------------  /\\\  |

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From: Philip Blundell <[email-masked]>
Date: Sun, 14 Nov 1999 12:59:14 +0000

>www.arm.linux.org, one that I compile myself from netwinder.org's CVS, etc):

The 2.3 tree in CVS has support for one ARM7500FE-based machine already; this 
might be a good starting point.  The 7500's IOMD block is not quite the 
same as the one in the RiscPC (and there are a few other differences too) so 
it will be hard to make one kernel run on both machines.

>!Linux -bootkernel kernel

BTW, the !Linux loader is not free software.  You might like to investigate 
LinLoader or some other alternative instead, since you will probably have to 
modify it to pass the right architecture number for a new machine.

>it up to a tuner card on my PC. 

Do you know how the TV output is arranged?

p.

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From: Randolph Chung <[email-masked]>
Date: Sun, 14 Nov 1999 06:38:54 -0700

> note, I don't like talking through people; mistakes happen.  It's better to

Just want to make sure I clarify this -- Chris has been more than helpful in
trying to help me get this setup. I'm posting to get some extra info, not
because of any fault on his part.

Unfortunately I'm going to be away for a few days. Will get on l-a-k as soon
as I return. Meanwhile, if any relevant emails come up, I'd appreciate a cc.

thanks much,
randolph

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From: Russell King - ARM Linux Admin <[email-masked]>
Date: Sun, 14 Nov 1999 13:47:31 +0000 (GMT)

> it will be hard to make one kernel run on both machines.

Err, not as far as I know.  If you want the ARM7500 stuff integrated at some
point, you know what to do.  (btw, it seems like the feature freeze in the main
kernel is dead).

> modify it to pass the right architecture number for a new machine.

The loader is free software, just not open-sourced.  Reason?  RISC OS is not
a platform which lends itself to open-source.
   _____
  |_____| ------------------------------------------------- ---+---+-
  |   |        Russell King       [email-masked]      --- ---
  | | | |  http://www.arm.linux.org.uk/~rmk/armlinux.html    /  /  |
  | +-+-+                                                     --- -+-
  /   |               THE developer of ARM Linux              |+| /|\
 /  | | |                                                     ---  |
    +-+-+ -------------------------------------------------  /\\\  |

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From: Philip Blundell <[email-masked]>
Date: Sun, 14 Nov 1999 14:38:57 +0000

Russell King wrote:
>Philip Blundell writes:
>> The 2.3 tree in CVS has support for one ARM7500FE-based machine already; 
>> this might be a good starting point.  The 7500's IOMD block is not quite the 
>Err, not as far as I know.

What are you referring to?

>If you want the ARM7500 stuff integrated at some point, you know what to do.

There are two 7500 patches currently sitting in your incoming queue (according 
to your web page) which have been there since August 9 and September 13.  What 
would you like me to do to speed things along?

>> BTW, the !Linux loader is not free software.
>
>The loader is free software, just not open-sourced.

`Free software' in the GNU sense means that the source is available, you can 
modify it, redistribute it and so on.  As I understand it !Linux is zero-cost 
software which is not the same.  My apologies if I have misrepresented the 
licence terms.

p.

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From: Russell King - ARM Linux Admin <[email-masked]>
Date: Sun, 14 Nov 1999 14:45:26 +0000 (GMT)

> What are you referring to?

The 2.3 CVS tree.

> software which is not the same.  My apologies if I have misrepresented the 

I'd like it to be open-sourced, but I just don't see that this is possible with
any RISC OS-based development system.  Any changes would have to be hand-patched
into the sources since there is no diff/patch utility that I am aware of, which
makes it impractical.
   _____
  |_____| ------------------------------------------------- ---+---+-
  |   |        Russell King       [email-masked]      --- ---
  | | | |  http://www.arm.linux.org.uk/~rmk/armlinux.html    /  /  |
  | +-+-+                                                     --- -+-
  /   |               THE developer of ARM Linux              |+| /|\
 /  | | |                                                     ---  |
    +-+-+ -------------------------------------------------  /\\\  |

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From: Philip Blundell <[email-masked]>
Date: Sun, 14 Nov 1999 15:08:40 +0000

>The 2.3 CVS tree.

That certainly did contain 7500 support last time I looked, assuming you are 
talking about the one at netwinder.org.

>I'd like it to be open-sourced, but I just don't see that this is possible 
>with any RISC OS-based development system.  Any changes would have to be 
>hand-patched into the sources since there is no diff/patch utility that I 
>am aware of, which makes it impractical.

It's several years since I used Acorn C but I thought it did come with a diff 
program.  Or one could use a Unix system for maintaining the source.  
Regardless, this seems like a tangential issue to the question of whether to 
actually release source or not.  LinLoader is GPL'd so there is an existence 
proof that RISC OS free software is possible.

p.

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From: Russell King - ARM Linux Admin <[email-masked]>
Date: Sun, 14 Nov 1999 15:23:35 +0000 (GMT)

> talking about the one at netwinder.org.

Naturally.

> proof that RISC OS free software is possible.

It's certainly not tangential at all.  It's a question of the amount of time
and tools.  There is a diff program, but it does not produce any sort of
output that could be passed into a patch-type program.  The output of !Diff
is only useful for documentation purposes.

This lack of a standard diff/patch is /the problem/ and /the reason/ why it's
not open-sourced.  If someone can show me a practical solution to this, then
it will get open-sourced.  Until that time, it remains as is.

Also, it's worth noting that !Linux cannot be linked by the newer Acorn tools,
since the AOF format has changed in non-backward compatable ways (which prevent
the non-source distributable library which the programs link against linking).

Basically, development on RISC OS is a mess, just like partitioning stuff on
Acorn machines.
   _____

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From: Ben Jameson <[email-masked]>
Date: Mon, 15 Nov 1999 10:11:45 -0000 (GMT)

On 14-Nov-99 Russell King - ARM Linux Admin wrote:

> This lack of a standard diff/patch is /the problem/ and /the reason/ why
> it's not open-sourced.  If someone can show me a practical solution to
> this, then it will get open-sourced.  Until that time, it remains as is.

The tools at:

  ftp://ftp.uni-stuttgart.de/pub/systems/acorn/riscos/unixtools/gnu/

may be of some help here, although they are rather old (I've not had
occasion to use them much).

There may be more recent ports elsewhere.

> Also, it's worth noting that !Linux cannot be linked by the newer Acorn
> tools, since the AOF format has changed in non-backward compatable ways
> (which prevent the non-source distributable library which the programs
> link against linking).

Would it be of any use to use GCC instead? (http://hard-mofo.dsvr.net/)

Ben.

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From: Chris Rutter <[email-masked]>
Date: Mon, 15 Nov 1999 14:50:44 +0000 (GMT)

On Sun, 14 Nov 1999, Russell King - ARM Linux Admin wrote:

> > LinLoader is GPL'd so there is an existence 

Yes, or for a rather good example, the Straylight Source Release, at
Mark Wooding's site: <http://www.excessus.demon.co.uk/>.

> it will get open-sourced.  Until that time, it remains as is.

There's a port at <ftp://ftp.zap.uk.eu.org/pub/ds/GNU/diffutils.zip>

diffutils are trivial to port, even if someone else *hadn't* ported
them before (which someone has).

-- 
Chris <[email-masked]>                         ( http://www.fluff.org/chris )

---

From: Chris Rutter <[email-masked]>
Date: Mon, 15 Nov 1999 14:44:31 +0000 (GMT)

On Sun, 14 Nov 1999, Russell King - ARM Linux Admin wrote

> Any changes would have to be hand-patched

There are four options, all practical as I see it:

  * Maintain the source under local RCS (using the RISC OS RCS port);
  * Maintain the source under Tytgat's RISC OS CVS port;
  * Maintain the source under CVS under Linux, and edit the sources over
    NFS (my preferred option);
  * Use no revision control system and use diff/patch[1].

[1] There are many diffutils ports; the most recent AFAIAA is Darren Salt's,
  available at <ftp://ftp.zap.uk.eu.org/pub/ds/GNU/diffutils.zip>.

---

From: Wookey <[email-masked]>
Date: Mon, 15 Nov 1999 13:52:55 +0000 (GMT)

> This lack of a standard diff/patch is /the problem/ and /the reason/
> why it's not open-sourced.  If someone can show me a practical solution
> to this, then it will get open-sourced.  Until that time, it remains as
> is.

If it would help, I am happy to do the (admittedly tedious) manual
patching/maintaining of the RISCOS tools, to relieve Russell for more
important things.

> (which prevent the non-source distributable library which the programs

Indeed, and in fact I can only compile some of the tools with the older
tools too, but that ought to be a solvable problem (given that it works
for Russell with a very similar toolset). Once I have solved that problem
I can usefully help maintain them.

The source is available from the FTP site so it is effectively
open-source although it is not GPLed.

> Basically, development on RISC OS is a mess, just like partitioning
> stuff on Acorn machines.

It's rather old-fashioned, but I wouldn't call it 'a mess'.

Wookey
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