From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
Date: Tue, 18 Mar 2014 15:43:41 -0400
To: 9fans@9fans.net
Message-ID: <ab02d4c5bb96760df30be0923d659b03@ladd.quanstro.net>
In-Reply-To: <20140318182858.GA746@spark.home>
References: <20140316155223.GA556@spark.home>
	<9e72419c18681b46d86755504e9bc14b@brasstown.quanstro.net>
	<20140317221942.GA313@spark.home>
	<97e0a383d9a82f2ad92c580962b6f34b@mikro.quanstro.net>
	<20140318182858.GA746@spark.home>
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Subject: Re: [9fans] Cannot boot plan9
Topicbox-Message-UUID: cbd27ab0-ead8-11e9-9d60-3106f5b1d025

> Do you think that there is a point in trying to solve it? Where should I
> start when I would like to fix this issue. Is it easy or rather hard
> task? How does the develop process looks like when doing such things?

i think this is a hard question to answer.  on the one hand, i don't want
to be discouraging or anything like that.  but on the other hand, it's a
little bit like a mensa question.  it's possible to get really stuck.  and there's
the h/w availability issue.

if you really want to do it, why don't you write a proposal.

since there are no docs, you will have to get the linux or *bsd driver,
and start disecting it.
1.  understand the general scope
2.  find bits like toe that can be completely dropped.
3.  work out what the os interface is.

since this gets boring and i tend to get antsy without working code,
i generally start writing a skeleton driver.  think of wirth's example of
writing a program.  it's a pretty good approach for drivers.

i'm sure you can recognize (but not drive) the hardware on the first day.
break things down into steps so that each bit of code adds functionality.
resist at all costs the temptation to have nothing working till the last
semicolon is in place.

that's my recommendation.

> > i would recommend running from usb on this machine.
> Does plan9 suport something like linux tmpfs?

ramfs.  on plan 9 this is a user-level process. you can run it at any time,
and concurrently run several in different namespaces.

> because when I boot
> the system from the image you have given me I cannot save any file. Does
> plan9 support saving the state of live session?

that's a bit surprising.

try
	echo >/lib/emptyfile

does that yield an error?

> > alternatively, find an ahci add in card.
> It's probably a noob question but how can I do this? Is it's controled
> by some bios software or it needs some hardware changes?

each add-in card determines the register interface it would like to present.
bios has no say in the matter.

- erik