From: brantley@coraid.com (Brantley Coile)
Subject: [TUHS] Reading UNIX V6: Does eash process has its own user
Date: Tue, 3 Oct 2006 15:40:07 -0400 [thread overview]
Message-ID: <2bda8189a5f15f1e8b106e662546b408@coraid.com> (raw)
In-Reply-To: <2051ec920610031123n10d2737cq977af058f98e7149@mail.gmail.com>
I'm reading from the printed Lion's commentary and I have the
following:
0742 mov (sp)+, r1
0743 mov (sp),KISA6
0744 mov $_u,r0
What are you looking at?
> hi Brantley,
>
> Now I start to understand what's going on.
>
> But do you mean 0744 by 0743?
> 0743 mov (sp), r0
> 0744 mov $_u, r0
>
> And 2230 should be 2229, which is:
> 2229 sureg();
>
> Thanks &
> Regards,
>
> Qinglai
>
> On 10/3/06, Brantley Coile <brantley at coraid.com> wrote:
>> Rp->p_addr is the address of the swappable image in core. The process
>> image begins with the user segment for that process. Line 0743 maps
>> the upage into the current address space (KISA6) and _retu loads
>> previously saved sp and r5 from there. Notice that on line 2230
>> Ken reloads the other memory mapping registers.
>>
>> Read the section `Memory Management' starting on page 2-4 for background
>> on this.
>>
>>
>> U.u_rsave is just a constant location in memory. Notice that rp->p_addr
>> isn't a byte address but a core click address in units of 64 bytes.
>>
>> Hope that helps.
>>
>> Brantley
>>
>> > The final question is about how savu/retu work.
>> >
>> > savu:
>> > line 0729 and line 0730: r5 and sp are saved to (r0) and (r0)+, which
>> > are the address of u.u_rsav.
>> >
>> > retu:
>> > 0746 and 0747: sp and r5 are read from (r0) and (r0)+, which is
>> > "rp->p_addr" (see line 2228). It looks weird to me. (Okay...I have to
>> > confess I look stupid here...) When making call to retu, why bother
>> > "retu(rp->p_addr)"? Why not calling with "retu(u.u_rsav)"? Does it
>> > mean that rp->p_addr == u.u_rsav?
>>
>>
prev parent reply other threads:[~2006-10-03 19:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-03 9:05 [TUHS] Reading UNIX V6: Does eash process has its own user structure, or all the processes share one copy of it? jigsaw
2006-10-03 9:33 ` Hellwig Geisse
2006-10-03 10:35 ` jigsaw
[not found] ` <74f31973c70413b149f1e383bf47dae0@coraid.com>
2006-10-03 18:23 ` [TUHS] Reading UNIX V6: Does eash process has its own user jigsaw
2006-10-03 19:40 ` Brantley Coile [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2bda8189a5f15f1e8b106e662546b408@coraid.com \
--to=brantley@coraid.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).