From owner-freebsd-hackers  Wed Jul 10  4:58: 8 2002
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 69D7A37B400; Wed, 10 Jul 2002 04:58:05 -0700 (PDT)
Received: from domestos.yandex.ru (domestos.yandex.ru [213.180.193.14])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 2E64443E42; Wed, 10 Jul 2002 04:58:04 -0700 (PDT)
	(envelope-from tzukanov@narod.ru)
Received: from dial-056.nross.ru ([195.161.59.183]:3712 "EHLO antares" ident:
	"NO-IDENT-SERVICE[2]" whoson: "tzukanov" TLS-CIPHER: <none> TLS-PEER:
	<none>) by mail.yandex.ru with ESMTP id <S1015283AbSGJL5r>;
	Wed, 10 Jul 2002 15:57:47 +0400
Content-Type: text/plain;
  charset="us-ascii"
From: Serguei Tzukanov <tzukanov@narod.ru>
To: freebsd-platforms@freebsd.org
Subject: A question about S/390 port
Date:	Wed, 10 Jul 2002 15:54:09 +0400
User-Agent: KMail/1.4.1
Cc: freebsd-hackers@freebsd.org
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Message-Id: <200207101554.09734.tzukanov@narod.ru>
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG

Some working notes.

I've written the libc/csu part, kernel successfully starts init and init 
forks off for the execve of -sh,
(http://tzukanov.narod.ru/freebsd390/bootlog.txt)
but there is problem with printing from userland, e.g. output from 
userland are not visible. Write syscall to descs 1,2 in init returns 
with success.
I'm sure it's something very stupid, so maybe someone have a clue?

And another problem (well-known?):
__syscall returns 64-bit value but mmap returns 4-byte word in the 
td->td_retval[0]. Wrapper for mmap in libc casts 64 rv to 32 and alays 
gets zero. This leads to truncating to zero due to cast on 32-bit 
big-endian architectures.
The solution is obvious - using constructs like
td->td_retval[_QUAD_LOWWORD] = xxx in MI code.

For now I just avoid it with hack in syscall handler.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message