[Qemu-devel] OS/2 Bootloader Some weird behaviour of branch instruction

All of lore.kernel.org
 help / color / mirror / Atom feed

From: Tero Kaarlela <turo.kaarlela@co.inet.fi>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] OS/2 Bootloader Some weird behaviour of branch instruction
Date: Wed, 25 May 2005 21:13:11 +0300	[thread overview]
Message-ID: <4294C037.2070509@co.inet.fi> (raw)

Hi,

    I took a look at qemu in_asm & cpu debugging with OS/2 bootloader 
under Qemu -prep. And there is something weird happening in my opinion:

This happens after boot.cfg has been gone through and kernel bootstrap 
task should start:

IN:
0xf0107068:  .long 0x10009d81
0xf010706c:  tdi    0,r0,27776
0xf0107070:  bl    F011EDF0    <<= Shouldnt this branch to F011EDF0 
instead of going on???
0xf0107074:  .long 0xb2c
0xf0107078:  cmpwi    r0,-32191

After this code branches back to 0x0f0107068(this block start) And does 
this same block again 42 times. Then:

----------------
nip=00000300 super=1 ir=0
translate opcode f01072ac (3c 16 0a)
invalid/unsupported opcode: 3c - 16 - 0a (f01072ac) 0x00000300 0
IN:
0x00000300:  lhau    r3,4336(r18)

----------------
nip=00000700 super=1 ir=0
translate opcode f0000730 (3c 18 1c)
invalid/unsupported opcode: 3c - 18 - 1c (f0000730) 0x00000700 0
IN:
0x00000700:  addic    r0,r7,240


Here is CPU debug from same:

---------------- excp: 0108
nip=0xf0107068 LR=0xf0107010 CTR=0xf01071e0 XER=0x20000000 MSR=0x00010031
GPR00: f01072ac f0000060 00000000 f0170004 00000001 40000000 00000010 
f0004100
GPR08: f0107010 84000023 f0107068 f01071e0 f0000000 f0000300 00000000 
20000000
GPR16: 00000004 38603000 60000000 00000000 0000b588 00000000 001990c7 
00195000
GPR24: 00000000 0000000c 00000041 40010031 00000010 00000000 f0000300 
f0170004
CR: 0x84000023  [ L  G  -  -  -  -  E  EO ] TB: 0x00000000 dd2f1962
FPR00: 6162636465666d00 0000000000000000 0000000000000000 0000000000000000
FPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR12: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
SRR0 0xf0102700 SRR1 0x00010031 DECR=0x22d0b634
reservation 0x00000000
invalid/unsupported opcode: 3c - 16 - 0a (f01072ac) 0x00000300 0
---------------- excp: 0007
nip=0x00000300 LR=0xf0107010 CTR=0xf01071e0 XER=0x20000000 MSR=0x00010001
GPR00: f01072ac f0000060 00000000 f0170004 00000001 40000000 00000010 
f0004100
GPR08: f0107010 84000023 f0107068 f01071e0 f0000000 f0000300 00000000 
20000000
GPR16: 00000004 38603000 60000000 00000000 0000b588 00000000 001990c7 
00195000
GPR24: 00000000 0000000c 00000041 40010031 00000010 00000000 f0000300 
f0170004
CR: 0x84000023  [ L  G  -  -  -  -  E  EO ] TB: 0x00000000 dd2fbe70
FPR00: 6162636465666d00 0000000000000000 0000000000000000 0000000000000000
FPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR12: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
SRR0 0xf0107068 SRR1 0x00000031 DECR=0x22d014be
reservation 0x00000000
invalid/unsupported opcode: 3c - 18 - 1c (f0000730) 0x00000700 0


So any ideas what might be reason for this?


Tero Kaarlela

next             reply	other threads:[~2005-05-25 18:28 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-05-25 18:13 Tero Kaarlela [this message]
2005-05-25 18:59 ` [Qemu-devel] OS/2 Bootloader Some weird behaviour of branch instruction Tero Kaarlela
2005-05-25 20:57   ` J. Mayer
2005-05-29 14:02     ` Tero Kaarlela

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=4294C037.2070509@co.inet.fi \
    --to=turo.kaarlela@co.inet.fi \
    --cc=qemu-devel@nongnu.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.