From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Db0cN-0006Z4-Qa for qemu-devel@nongnu.org; Wed, 25 May 2005 14:28:36 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Db0cL-0006YX-BO for qemu-devel@nongnu.org; Wed, 25 May 2005 14:28:34 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Db0cJ-0006Om-Qw for qemu-devel@nongnu.org; Wed, 25 May 2005 14:28:32 -0400 Received: from [194.251.242.243] (helo=fep18.inet.fi) by monty-python.gnu.org with esmtp (Exim 4.34) id 1Db0Nx-0006xI-Dz for qemu-devel@nongnu.org; Wed, 25 May 2005 14:13:41 -0400 Received: from co.inet.fi ([80.220.124.133]) by fep18.inet.fi with ESMTP id <20050525181311.QTRJ16444.fep18.inet.fi@co.inet.fi> for ; Wed, 25 May 2005 21:13:11 +0300 Message-ID: <4294C037.2070509@co.inet.fi> Date: Wed, 25 May 2005 21:13:11 +0300 From: Tero Kaarlela MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] OS/2 Bootloader Some weird behaviour of branch instruction Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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