From owner-freebsd-bugs@freebsd.org Sun Jan 15 21:08:55 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B9F88CB184D for ; Sun, 15 Jan 2017 21:08:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id AA0A41B25 for ; Sun, 15 Jan 2017 21:08:55 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v0FL8tPH087526 for ; Sun, 15 Jan 2017 21:08:55 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 216123] ofwfb: r269278 broke booting on Power Mac G4 Date: Sun, 15 Jan 2017 21:08:55 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: tgl@sss.pgh.pa.us X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 15 Jan 2017 21:08:55 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D216123 Bug ID: 216123 Summary: ofwfb: r269278 broke booting on Power Mac G4 Product: Base System Version: CURRENT Hardware: powerpc OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: tgl@sss.pgh.pa.us I've been trying to install FreeBSD on a Power Mac G4 ("PowerMac 3,6", a/k/a Mirrored Drive Doors 2003). 10.3 works fine, but neither 11-STABLE nor CURRENT are able to boot. I've bisected the problem and can state confidently that this commit broke it: r269278 | nwhitehorn | 2014-07-29 19:11:05 -0400 (Tue, 29 Jul 2014) | 6 l= ines Make mmap() of the console device when using ofwfb work like other suppor= ted framebuffer drivers. This lets ofwfb work with xf86-video-scfb and makes the driver much more generic and less PCI-centric. This changes some user-visible behavior and will require updates to the xorg-server port on PowerPC when using ATI graphics cards. The immediately preceding commit boots fine, with or without kernel debug options. (Well, I have to back-patch r269365 and r305901, but then it boots fine.) With r269278, the behavior is one of these: * kernel debug options enabled: seems to freeze immediately at boot. After the boot loader says it's booting the kernel, the screen goes black as expected, but no kernel output text ever appears. * kernel debug options disabled: fatal kernel trap after a few dozen lines of dmesg output. I've transcribed a screen shot: ... gem0: 10kB RX FIFO, 4kB TX FIFO gem0: Ethernet address: (machine's MAC address here) cryptosoft0: on nexus0 fatal kernel trap: exception =3D 0xd0004840 (unknown) srr0 =3D 0x0 srr1 =3D 0x0 lr =3D 0x861104 curthread =3D 0 panic: unknown trap cpuid =3D 0 KDB: stack backtrace: #0 0x4a93ac at panic+0x16c #1 0x861308 at trap_fatal+0x1bc #2 0x8622e4 at trap+0xfb4 #3 0x84fef0 at powerpc_interrupt+0x170 Uptime: 1s (reboots) Furthermore, on the way to isolating when the problem was introduced, I discovered that the non-debug behavior changed from a trap to a silent freeze at r279750 ("Make 32-bit PowerPC kernels, like 64-bit PowerPC kernels, position-independent executables"). It seems to occur at the same place though, right after reporting cryptosoft0, so I suppose that it's the same bug manifesting differently. These behaviors of freeze at boot with debug options, or freeze after "cryptosoft0" without, are still present in CURRENT and 11-STABLE. I gather from recent reports on the freebsd-ppc list that a number of other people see these same behaviors, but not everyone does. I am unable to offer a theory as to just what the triggering difference is, or how the bug might be fixed. But I'd be happy to run further testing if given some guidance. --=20 You are receiving this mail because: You are the assignee for the bug.=