RE: [9fans] source code as data not text

RE: [9fans] source code as data not text

[David Gordon Hogan]

> I would rather have code stored in a
> clustered rdbms that is accessed through its own shell [that is
> cross-platform like limbo]

The last thing we need is another shell.

What if the code were accessed through a file system interface
which is cross-platform?

Re: [9fans] source code as data not text

[Steve Kilbane]

dhog:
> What if the code were accessed through a file system interface
> which is cross-platform?

As has been pointed out, how something is stored isn't that relevant
here; the issue is *what*, and the principle issue is whether your
program is stored as ascii source, or as some other representation
(that presumably adds additional structuring, else why bother?)

If you're storing an ascii file, then whether you store it in
a cvs-like system, an RDBMS or something entirely different isn't
that much more important than whether it's stored in a file system
that's on a local disk or a networked one: you may need to use
special means to retrieve it, but that's your call.

If it's plain ascii, and you've got an editor that can show pretty
colours, then fine. I'm happy for you, and it doesn't mean that anything
special has to be done to the file that'll stop it working on any other
editor.

If your source file is saved as something that represents additional
structure, then I'd suggest you're using the wrong terminology: that's
an object file, that's been compiled into another representation. From
here on in, you need a special set of tools to interpret and manipulate
the contents of that file. Regardless of the means by which you retrieved
the file, it's effectively a black box to most of the surrounding
system.

As I've said for many a year, "standardise on file formats and protocols,
and the applications take care of themselves."

steve

RE: [9fans] source code as data not text

[Richard Elberger]

>
>As has been pointed out, how something is stored isn't that relevant
>here; the issue is *what*, and the principle issue is whether your
>program is stored as ascii source, or as some other representation
>(that presumably adds additional structuring, else why bother?)
>
>If you're storing an ascii file, then whether you store it in
>a cvs-like system, an RDBMS or something entirely different isn't
>that much more important than whether it's stored in a file system
>that's on a local disk or a networked one: you may need to use
>special means to retrieve it, but that's your call.
>

How something is stored is very relevant to source management -- you'd
better ask the operations folks who have to run the hardware and are
responsible for maintaining data integrity.

-- rich

Re: [9fans] source code as data not text

[Steve Kilbane]

> How something is stored is very relevant to source management

Sigh. I was trying to clarify the issues, but obviously failed.
I'll try a different tack.

The discussion started off with syntax-directed editors, picked
up issues concerned with proprietary file formats, and then moved
into proprietary repositories versus things with a file-system.
My apologies for over-simplifying.

My point was merely this: given a file that contains some
representation of source, the issues of the file's internal
structure, the structure of the repository that holds the
file, and the how the file's contents are rendered
to the user are distinct issues and should not be confused.

The storage system is not relevant in all cases, but in the
discussion of what you do with a file _once you've retrieved
it from the storage system_, it is.

steve

RE: [9fans] source code as data not text

[Richard Elberger]

Yes, I think my wording was too general.  Yes, too many shells like sh and
ksh, but I wasn't thinking a cmd line shell -- just would like to see a
standard wrapper for the handling of code, how it maps to business (or
other) process -- like if a "feature module" will be plugged in or not to
the build, and how that is managed/operated, knowing where the code was
coming from, what environment it was written in, what scenarios/environment
it was unit tested in, etc ... a lot of things to track and imo it is all
important (though varying in degrees of importance).  Kind of like an app,
but it is basically a software team's creative bucket -- a system that is
self-enclosed and shares namespaces (be it source, devices, or workspaces).
So much stuff and syntax checking is just part of an app that is part of
what should be a consistent system to minimize risk.

I already thought of styx, and how it would be excellent to leverage this
for a full-on collaborative development environment.  It would be a huge
undertaking to create something like this, and it would be very exciting.

-- rich

>-----Original Message-----
>From: 9fans-admin@cse.psu.edu [mailto:9fans-admin@cse.psu.edu]On Behalf
>Of David Gordon Hogan
>Sent: Tuesday, 19 June 2001 6:49 a.m.
>To: 9fans@cse.psu.edu
>Subject: RE: [9fans] source code as data not text
>
>
>> I would rather have code stored in a
>> clustered rdbms that is accessed through its own shell [that is
>> cross-platform like limbo]
>
>The last thing we need is another shell.
>
>What if the code were accessed through a file system interface
>which is cross-platform?
>
>

Re: [9fans] source code as data not text

[Boyd Roberts]

my man dhog speaks ths truth:

> The last thing we need is another shell.

how many does vita's inferno have?  n too many.

Re: [9fans] sam vs acme

[David Gordon Hogan]

boyd@fr.inter.net writes:
> no, that _thing_ will bite you further down the track and it
> was foolish to build it.

Sadly, that thing often bites everyone else down the track,
not just its perpetrator.

Re: [9fans] sam vs acme

[James A. Robinson]

Random thoughts on acme, sam, and the acme clone wily...

I've never used the real acme for any length of time, but I did use wily
for many years under Linux and Solaris.  For the past year or so I've
been using sam as my main editor.  I just installed the latest Inferno
updates and have played around with the new Inferno acme (now with Edit!).

One thing that wily had in commmon with acme was the concept of a scratch
window, and it had the ability to have guides.  While I liked that,
I also very much like sam's ~~sam~~ body.  The concept of a window for
edit commands to run on the active window is very nice.  With wily,
if you execute >, <, or | commands, it runs it on the selected text in
what it thinks is the active body.  That's a nice feature, similar in
concept to the ~~sam~~ window.

The reason I like an entry window or scratch space which works on the
most recent selecteed text is that I don't have enough space to work in
the tag.  Because acme uses full file names, often I find myself with
not much space in the tag for |, >, or < commands. I know it will scroll
along, but for some reason I just don't like typing commands into the
tag when the front half gets scrolled off the left-hand edge.

I don't know if Plan 9 acme takes advantage of shell variables, but the
one in inferno doesn't appear to.  One thing nice about wily was that
you could have defined $pisa_util/JournalLister.java to reference the
file /home/jimr/proj/pisa/src/org/highwire/util/JournalLister.java.

Now that acme has the Edit command, sam's power is available but,
unless I'm missing something, it's still a bit of a disconnect using
Edit on a window.  Using the tag works, but it is kind of restrictive
in terms of space (I often use varitions of x/pat/ { nested commands }).
Using Edit commands picked up from a scratch body  (cut, paste, move to
target body's tag and paste into Edit) works well enough, but I'd really
love to see an ~~acme~~ body which just knows the last active body, and
lets me execute commands I type in or mouse2 on.  I'm curious whether
or not anyone else has the same interface tastes?

My other thought is that, if an ~~acme~~ window were created so commands
ran on a server on the other side of a wire, it would be very fast to
make edits on large files, since all the data could be processed on the
server side -- you would only pull down updates to the visible portion.
I know Rob mentioned he had thought about a client/server approach to
acme, and think that is an awesome idea.


Jim

Re: [9fans] sam vs acme

[Steve Kilbane]

Jim mused:

> target body's tag and paste into Edit) works well enough, but I'd really
> love to see an ~~acme~~ body which just knows the last active body

this worked in sam because of click-to-type. i don't know whether it
would work in acme. it *could* work in wily, since wily remembers the
last window on which you clicked; it did so in order that | > < would
work from misc guide files.

Re: [9fans] sam vs acme

[Boyd Roberts]

From: "David Gordon Hogan" <dhog@plan9.bell-labs.com>
> Sadly, that thing often bites everyone else down the track,
> not just its perpetrator.

oh so true ...

Re: [9fans] Virtual memory in BSD and Plan9

[David Gordon Hogan]

> One big difference I've seen in past examples of paging systems
> can be summarized as: page against everyone vs. page only against
> oneself.  The latter is sometimes called the "working set" model.
> The former tends to make the whole system unusable when a process
> lets its address space get out of control, while the latter tends
> to run other processes pretty much the same under such conditions.

I'm wondering if anyone's ever tried to treat this as a `bandwidth sharing'
issue, and applied techniques like Fair Queueing.

Admittedly it's more complex than a simple bandwidth sharing problem.
There are two resources to share: the page pool and the paging device
IO, and there are interactions between the two.

Re: [9fans] Virtual memory in BSD and Plan9

[Scott Schwartz]

| I'm wondering if anyone's ever tried to treat this as a `bandwidth sharing'
| issue, and applied techniques like Fair Queueing.

Wasn't there a usenix paper by someone at the labs a while back on
something like that?

Re: [9fans] on TCP vs IL

[David Gordon Hogan]

> Not to
> mention gorgeously huge address-space, which makes for consideration of
> interesting mappings of persistant datastore into the network address space.

You _could_ do that.  But some of us would Persistantly Object.

Do you really want each byte to have its own IP address?

Re: [9fans] on TCP vs IL

[George Michaelson]

> >Not to
> >mention gorgeously huge address-space, which makes for consideration of
> >interesting mappings of persistant datastore into the network address space.
>
> You _could_ do that.  But some of us would Persistantly Object.
>
> Do you really want each byte to have its own IP address?
>

Um.. why not? I mean, in the reductionist world of theoretical wanking
of which I am an exemplar, isn't this precicely what persistant distributed
programming is maybe about?

There was a school of thought around this stuff from Glasgow a few years
back doing Persistant Pascal. I seem to recall 128-bit disk addressing being
on the table. This was an analogue, a corrollary of the 128bit VLIW model
of instruction wasn't it? Its not a long jump from disk address to network
address if you consider the namespaces ideas is it?

cheers
	-George
--
George Michaelson       |  APNIC
Email: ggm@apnic.net    |  PO Box 2131 Milton QLD 4064
Phone: +61 7 3367 0490  |  Australia
  Fax: +61 7 3367 0482  |  http://www.apnic.net

Re: [9fans] on TCP vs IL

[Thomas Bushnell, BSG]

dhog@plan9.bell-labs.com (David Gordon Hogan) writes:

> > Not to
> > mention gorgeously huge address-space, which makes for consideration of
> > interesting mappings of persistant datastore into the network address space.
>
> You _could_ do that.  But some of us would Persistantly Object.
>
> Do you really want each byte to have its own IP address?

Yes, frankly, I would love that.  It might be too expensive, but if
not, it would truly be wonderful to have.

Re: [9fans] on TCP vs IL

[Douglas A. Gwyn]

"Thomas Bushnell, BSG" wrote:
> dhog@plan9.bell-labs.com (David Gordon Hogan) writes:
> > Do you really want each byte to have its own IP address?
> Yes, frankly, I would love that.  It might be too expensive, but if
> not, it would truly be wonderful to have.

Personally I wish each *bit* in the universe had a unique address.

Re: [9fans] on TCP vs IL

[Thomas Bushnell, BSG]

"Douglas A. Gwyn" <DAGwyn@null.net> writes:

> "Thomas Bushnell, BSG" wrote:
> > dhog@plan9.bell-labs.com (David Gordon Hogan) writes:
> > > Do you really want each byte to have its own IP address?
> > Yes, frankly, I would love that.  It might be too expensive, but if
> > not, it would truly be wonderful to have.
>
> Personally I wish each *bit* in the universe had a unique address.

Heh, yeah, that would be nice.  Though, as I was once taught, a "byte"
is officially the minimal addressible unit on an architecture... if
every bit is separately addressed, then hey, we've just switched to
one-bit bytes, right?

But these days the philistines have forgotten about fine old 36-bit
wordsize machines and the like, and have just synonymized "byte" and
the neologism "octet".

Sic transit gloria computorum.

Re: [9fans] on TCP vs IL

[Douglas A. Gwyn]

"Thomas Bushnell, BSG" wrote:
> ...  Though, as I was once taught, a "byte"
> is officially the minimal addressible unit on an architecture...

No, although within C the term "byte" is practically synonymous
with "minimum unit addresable by standard language constructs".

Generally, a byte is a collection of bits within a machine word
that are treated as representing a complete field.  Some systems
had variable-sized byte instructions, some had fixed-size byte
operations, some had no direct support for bytes (although one
could use word-oriented instructions to manipulate artificially
defined byte fields).

> But these days the philistines have forgotten about fine old 36-bit
> wordsize machines and the like, and have just synonymized "byte" and
> the neologism "octet".

The 8-bit byte became common with 16-bit minicomputers and the
IBM System/360.  Consequently when storage devices for those
platforms had their capacity specified in "bytes", everyone
understood that to mean 8-bit bytes.  This carried over into
other processors, especially since the 8-bit byte sufficed for
the most common character encodings of the time, ASCII and
EBCDIC.  But since "byte" does not logically always imply
8 bits, careful specifications such as the IETF Internet RFPs
tend to use the term "octet" when exactly 8 bits are meant.

Re: [9fans] libXg/test.c

[David Gordon Hogan]

[-- Attachment #1: Type: text/plain, Size: 437 bytes --]

I started unifying all the various ``Plan 9 on Unix & Nt'' thingies
a while ago, but I got bogged down trying to make a better
Inferno, which nobody (here at least) really wanted.

I've shelved the Inferno effort.  Russ has been helping with
drawterm, on and off.  I might spend some time over the
weekend tidying up the remainder of "9pm".  There shouldn't
be all these different versions of sam and the supporting libraries.


[-- Attachment #2: Type: message/rfc822, Size: 1698 bytes --]

From: Boyd Roberts <boyd@strakt.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] libXg/test.c
Date: Fri, 07 Dec 2001 20:15:39 +0100
Message-ID: <3C11155B.9D4309DD@strakt.com>

> The "9libs" version of libXg doesn't appear
> to have this problem.

My version came from:

    http://netlib.bell-labs.com/netlib/research/sam.shar.gz

Re: [9fans] libXg/test.c

[Boyd Roberts]

> There shouldn't be all these different versions of sam and the supporting libraries.

Right!

Re: [9fans] libXg/test.c

[Scott Schwartz]

David writes:
> There shouldn't be all these different versions of sam and the supporting
> libraries.

What he said.  Sign me up for the cleanup project.

Re: [9fans] libXg/test.c

[Boyd Roberts]

> What he said.  Sign me up for the cleanup project.

Please try and factor in being able to turn off UTF
to make latin-1 on unix bearable.  It's probably a
compile time thing, unless you live in 'mixed' universe.

In a 'mixed' universe it's probably pretty tricky to
do in any simple, general way.

Thanks.

Re: [9fans] libXg/test.c

[Maarit Maliniemi]

In article <20011207200957.4622.qmail@f.bio.cse.psu.edu>,
9fans@cse.psu.edu wrote:

>  Sign me up for the cleanup project.

Since Mark is very busy with other things I am sure that interested
parties can just ask for 9libs. Provided that one wants to use auto-tools,
ofcourse.
Sam-9libs is always avaliable for anybody that wants to do something in C.
After beeing allowed back into heaven (HLL coding) I have great
difficulties persuading myself to start activly maintaing it again.

bengt

Re: [9fans] libXg/test.c

[Leo Caves]

David Gordon Hogan wrote:
>
> I started unifying all the various ``Plan 9 on Unix & Nt'' thingies
> a while ago, but I got bogged down trying to make a better
> Inferno, which nobody (here at least) really wanted.
>


David, care to elaborate on how you were trying to better inferno?
Leo

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[David Gordon Hogan]

> Oops. I did not combine using the wavelan and trying
> to use the i81x driver. If I do have a wavelan in the
> pcmcia slot and I let aux/vga be run (trying i81x on
> thinkpad R31, mouseport ps2, vgasize 640x480x8, monitor xga)
> I get:
>
> panic: mmuwalk2: va 80526000 entry 4001E3

The i81x driver uses mmuwalk() to get the PTE of a single
page that it allocates for the hardware cursor.  It needs this
to mark the memory as uncached, otherwise the hardware
cursor won't update correctly.  Unfortunately, this strategy
only works if the cursor is allocated in the first 4M of memory.
After that, it isn't possible to single out an individual page
in the kernel virtual mapping.  Hence the panic.

I'm not sure how to fix this.  It might be neccesary to change
the page table to make the appropriate 4M region use a level
2 page table.

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Scott Schwartz]

| page that it allocates for the hardware cursor.

Can someone remind me why we can't use software cursors in 4e?

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Charles Forsyth]

[-- Attachment #1: Type: text/plain, Size: 619 bytes --]

i think that's what we found when we did VESA-based
work for Inferno.  i'm happy to parcel that up yet
again if anyone's seriously interested in adapting it
for Plan 9, or even current Inferno, or anything else
for that matter, but it takes time to find all the bits,
so be reasonably sure you're going to have the stamina.
other `buts': it relied on software cursors in Inferno;
it relied on non-trivial changes to the bootstrap code
to do real-mode (unreal mode more like) BIOS calls
to gather data before loading the kernel, because cards
didn't implement the 32-bit variants; and it's all
a bit involved.

[-- Attachment #2: Type: message/rfc822, Size: 1571 bytes --]

From: "Russ Cox" <rsc@plan9.bell-labs.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c
Date: Wed, 18 Sep 2002 07:38:59 -0400
Message-ID: <c638d4fcbdf1f3ffb4afccb80d0178b0@plan9.bell-labs.com>

> VBE/AF Standard 1.0

Right.  If I recall correctly and nothing has changed since
then (neither is overwhemlingly likely; it was 1999), most
cards don't bother implementing this part of the standard.

Russ

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Russ Cox]

> VBE/AF Standard 1.0

Right.  If I recall correctly and nothing has changed since
then (neither is overwhemlingly likely; it was 1999), most
cards don't bother implementing this part of the standard.

Russ

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[paurea]

Russ Cox writes:
 > > VBE/AF Standard 1.0
 >
 > Right.  If I recall correctly and nothing has changed since
 > then (neither is overwhemlingly likely; it was 1999), most
 > cards don't bother implementing this part of the standard.
 >

What about the other standards?. Using sw cursor and VESA for other
things how many cards would be really supported?. (just a question out
of shear curiosity).
--
                 Saludos,
                         Gorka

"Curiosity sKilled the cat"

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Russ Cox]

we already have loadable kernel modules.
they are called user-level file servers.

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Lucio De Re]

On Wed, Sep 18, 2002 at 12:49:03AM -0400, Russ Cox wrote:
>
> we already have loadable kernel modules.
> they are called user-level file servers.

Agreed.  But they have to straddle the user-kernel context, at a
price - Microsoft tried to keep graphics out the kernel, with well
known results (NT 3.51).

Being able to add kernel-level file servers would be an interesting
proposition, although I would have trouble understanding the concept
:-)

++L

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Russ Cox]

> Isn't always there the possibility to add a hwcursor also?. I think hw
> cursors are directly supported by VESA standards, but I think one
> thing is independant from another. Isn't it possible to use VESA for
> mode switching or whatever and reduce the code you have to write for
> the card to write the hwcursor support?.

VESA actually says nothing about hardware cursors
last I checked; if you're going the VESA route you
really want to reduce the necessary code to zero.
There's an important qualitative difference
between zero and non-zero.  Mainly, people who
don't write drivers are still up to the task of
writing zero lines of code.

> Another question. What is the software cursor really necessary for?
> (other than in vmware). Do there really exist modern cards
> which don't support hardware cursor?.

Full-screen VMware is another thing I'd forgotten
about.  But yes, most modern cards have hardware
cursors.

Russ

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[paurea]

Russ Cox writes:
 > VESA actually says nothing about hardware cursors
 > last I checked; if you're going the VESA route you
 > really want to reduce the necessary code to zero.
 > There's an important qualitative difference
 > between zero and non-zero.  Mainly, people who
 > don't write drivers are still up to the task of
 > writing zero lines of code.



Taken from www.vesa.org/standards.htm. this is the reason I thought VESA
standards supported hw cursors...

August
1996
VBE/AF Standard 1.0: The VBE/AF 1.0 defines the interface of a new operating system portable, loadable device driver architecture that will provide access to accelerated graphics hardware. Some of the accelerator functions supported include hardware cursors, multi buffering, solid and transparent off-screen bitmaps, rectangel filling, line drawing and polygon filling.


I found the part of writing the hw cursor support for the sis630 the easy part
of the driver, though. That is why I said that mode switching or whatever
could be done using VESA and add the specific code of the hw cursor appart.

By the way if you are writing a VESA driver and I can help in any way (even
with my lack of knowledge), tell me. I have given a lot of thought to it.
--
                 Saludos,
                         Gorka

"Curiosity sKilled the cat"

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[rob pike, esq.]

> Can someone remind me why we can't use software cursors in 4e?

Another way of saying is that when the draw code was written, replacing
the bitblt driver, software cursors were left out in order to simplify things.
If you don't attempt to remove support for old cruft, it accumulates forever.
Complete rewrites are an excellent opportunity to eliminate unnecessary
compatibilities, and I think the case for software cursors  remains
weak unless you're in the 0.1% of the population that needs the support.
How much complexity should the kernel have - and require people to
maintain -  for low-deployment devices?

-rob

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Lucio De Re]

On Tue, Sep 17, 2002 at 07:13:59PM -0400, rob pike, esq. wrote:
> How much complexity should the kernel have - and require people to
> maintain -  for low-deployment devices?
>
Only as much as can't be put somewhere else.  That's the problem with
a monolithic kernel: _everything_ that needs to be in there will
eventually appear in it.

Was it dhog that was working on loadable kernel drivers?

++L

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[rob pike, esq.]

That wasn't my point.  My point was that I don't consider an
absolute necessity that every possible device be supported.
I favor simplicity and maintainability over universality.

-rob

--On Wednesday, September 18, 2002 6:18 AM +0200 Lucio De Re
<lucio@proxima.alt.za> wrote:

> On Tue, Sep 17, 2002 at 07:13:59PM -0400, rob pike, esq. wrote:
>> How much complexity should the kernel have - and require people to
>> maintain -  for low-deployment devices?
>>
> Only as much as can't be put somewhere else.  That's the problem with
> a monolithic kernel: _everything_ that needs to be in there will
> eventually appear in it.
>
> Was it dhog that was working on loadable kernel drivers?
>
> ++L

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Lucio De Re]

On Wed, Sep 18, 2002 at 12:42:05PM -0400, rob pike, esq. wrote:
>
> That wasn't my point.  My point was that I don't consider an
> absolute necessity that every possible device be supported.
> I favor simplicity and maintainability over universality.
>
There's tension between these objectives, with the marketplace
driving one end and good practice resisting.

I vote on your side, but I accept that there is a price to pay.
I particularly baulk when backwards compatibility suffers, because
obsolescence is unaffordable but unstoppable in the third world
(developing countries).

Guess who's keenly aware that the World Summit on Sustainable
Development was held on his doorstep?

++L

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Russ Cox]

> Can someone remind me why we can't use software cursors in 4e?

Because the code doesn't exist.

Usually the code also complicates lots of other
aspects of the system, so it's been easier just to
implement the hardware cursor drivers.  If I ever
really want VESA-based drivers, I'll need a software
cursor implementation.  I have some ideas about
doing it without complicating everything else,
but they're not particularly well formed.

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[paurea]

Russ Cox writes:
 > Usually the code also complicates lots of other
 > aspects of the system, so it's been easier just to
 > implement the hardware cursor drivers.  If I ever
 > really want VESA-based drivers, I'll need a software
 > cursor implementation.

Isn't always there the possibility to add a hwcursor also?. I think hw
cursors are directly supported by VESA standards, but I think one
thing is independant from another. Isn't it possible to use VESA for
mode switching or whatever and reduce the code you have to write for
the card to write the hwcursor support?.

 >I have some ideas about
 > doing it without complicating everything else,
 > but they're not particularly well formed.

Another question. What is the software cursor really necessary for?
(other than in vmware). Do there really exist modern cards
which don't support hardware cursor?.
--
                 Saludos,
                         Gorka

"Curiosity sKilled the cat"

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[rob pike, esq.]

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Because the code was hideous (the mouse is hideous enough as is) and
because almost all VGAs in use have hardware support.

The mouse needs its Nth complete rethink, given the advent of USB mice.
It's someone else's turn, though.

-rob

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From: Scott Schwartz <schwartz@bio.cse.psu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c
Date: Tue, 17 Sep 2002 18:08:06 -0400
Message-ID: <20020917220806.3872.qmail@g.bio.cse.psu.edu>

| page that it allocates for the hardware cursor.

Can someone remind me why we can't use software cursors in 4e?

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Charles Forsyth]

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i know it's needed on earlier thinkpads, at least, to allow pcmcia
cards to work.  i remember a frustrating attempt to get a modem card
going on the butterfly thinkpad that was resolved by a similar change
(once i'd finally noticed that a Linux pcmcia configuration file
handled the thinkpad specially and started its equivalent scan at
0xD0000, presumably because the thinkpad has got something else there).

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From: YAMANASHI Takeshi <uncover@beat.cc.titech.ac.jp>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c
Date: Tue, 17 Sep 2002 13:19:15 0900
Message-ID: <200209170418.g8H4Ikv240064@mail-o.cc.titech.ac.jp>

Just allow me to describe my case...

> > 	p = KADDR(0xD0000); /*RSC: changed from 0xC0000 */
 :
> Sadly I don't remember why I changed that.
> It was a long time ago.  I think umbscan is just
> flawed at the moment

umbscan thought that the starting umb address is
0xCA000.  But reading the cis mapped at the
address ever returned 0xFF.  The change fixed the
cis reading problem and 3C562 started to work.

Thanks.
--

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Axel Belinfante]

On the thinkpad R31 I'm playing with right now the wavelan is not
recognized. I wonder whether this (well-timed :-) thread gave me
the explanation and the fix. I'll try it and report the result.

Axel.

> i know it's needed on earlier thinkpads, at least, to allow pcmcia
> cards to work.  i remember a frustrating attempt to get a modem card
> going on the butterfly thinkpad that was resolved by a similar change
> (once i'd finally noticed that a Linux pcmcia configuration file
> handled the thinkpad specially and started its equivalent scan at
> 0xD0000, presumably because the thinkpad has got something else there).

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Axel Belinfante]

I tried (changed /sys/src/9/pc/memory.c)
and the wavelan works now on the R31.
I did not yet check if this change makes a difference
(in a negative way) on `my' other systems.

W.r.t. the R31: Unfortunately, vga does not work (yet?)
(tried the i81x driver).
(the screen changes color slowly in a (when I saw it first time)
 disturbing way -- not everything changes at the same time --
 until I end up with a white/grey screen. no mouse, no menus)

Axel.

> On the thinkpad R31 I'm playing with right now the wavelan is not
> recognized. I wonder whether this (well-timed :-) thread gave me
> the explanation and the fix. I'll try it and report the result.
>
> Axel.
>
> > i know it's needed on earlier thinkpads, at least, to allow pcmcia
> > cards to work.  i remember a frustrating attempt to get a modem card
> > going on the butterfly thinkpad that was resolved by a similar change
> > (once i'd finally noticed that a Linux pcmcia configuration file
> > handled the thinkpad specially and started its equivalent scan at
> > 0xD0000, presumably because the thinkpad has got something else there).
>

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Axel Belinfante]

Oops. I did not combine using the wavelan and trying
to use the i81x driver. If I do have a wavelan in the
pcmcia slot and I let aux/vga be run (trying i81x on
thinkpad R31, mouseport ps2, vgasize 640x480x8, monitor xga)
I get:

panic: mmuwalk2: va 80526000 entry 4001E3

ktrace /kernel/path 80106720 807bf234
[11 lines of numbers omitted]
cpu0: exiting

Booting the same kernel, but without wavelan,
or without running aux/vga (e.g. by specifying mouseport 'a a')
does not give the panic.
The kernel is newer than the remainder of the system.
I'll update the machine from sources and retry.

Axel.

I wrote:
> I tried (changed /sys/src/9/pc/memory.c)
> and the wavelan works now on the R31.
> I did not yet check if this change makes a difference
> (in a negative way) on `my' other systems.

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[YAMANASHI Takeshi]

Just allow me to describe my case...

> > 	p = KADDR(0xD0000); /*RSC: changed from 0xC0000 */
 :
> Sadly I don't remember why I changed that.
> It was a long time ago.  I think umbscan is just
> flawed at the moment

umbscan thought that the starting umb address is
0xCA000.  But reading the cis mapped at the
address ever returned 0xFF.  The change fixed the
cis reading problem and 3C562 started to work.

Thanks.
--

Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c

[Russ Cox]

> I noticed boot/pc/memory.c has the line:
> 	p = KADDR(0xD0000); /*RSC: changed from 0xC0000 */
> but 9/pc/memory.c remains still:
> 	p = KADDR(0xC0000);
>
> I don't know what I did, but without changing the
> 9/pc/memory.c according to boot's, 3C562 didn't work
> on my laptop (MITSUBISHI Pedion).

Sadly I don't remember why I changed that.
It was a long time ago.  I think umbscan is just
flawed at the moment -- we really need to grab
the BIOS memory map before we dive into
protected mode, and use that instead of guessing
at these things.

Russ

[9fans] /sys/src/^(9 boot)^/pc/memory.c

[YAMANASHI Takeshi]

I noticed boot/pc/memory.c has the line:
	p = KADDR(0xD0000); /*RSC: changed from 0xC0000 */
but 9/pc/memory.c remains still:
	p = KADDR(0xC0000);

I don't know what I did, but without changing the
9/pc/memory.c according to boot's, 3C562 didn't work
on my laptop (MITSUBISHI Pedion).

Russ>
> I still do one-machine kernel development more often
> than I'd like, and it's just no fun.

I had to do one-machine kernel investigation in this case
for I have only one laptop.  It was somewhere between
reasonable pain and extreme fun.
--