From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.treblig.org (mx.treblig.org [46.235.229.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CE7927A135 for ; Mon, 3 Nov 2025 01:48:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.235.229.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762134527; cv=none; b=A0VC2uXWDYs4L/TonZU0q/Iha+kFOIZOWumEOUKwKxNz0gRmxwzl3HUdXabdrpT9p3yUupfW99QkZHIaDzC4+JgyAXql4OIoDM7lKfQ0XMMMZA8nYQy3RFbkr1tsPpSAKmMeOxKVrEYLs7j+8WDINFyJ/2aNUxIF71N3ZQt0yLk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762134527; c=relaxed/simple; bh=VNjifc4beAKhf95qBl71+1nj8WFLRt5F42DJlTYYoKI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KQ50FTBTH1VbuGfyCDfCURgFRCVDzQZGO3iqE7XpDyfAZTv/jGRnBhiznlQujPHHFc+izHwYYOp4kNTxZfqIvZ/cYMaZAbK6RZk+6WXuTaJOHJwXvgti43kjbag0h8x5ITrbA7a6bY1gtdo3v19lkdLNcdKFRkxiIGuDmVJ0UeU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=treblig.org; spf=pass smtp.mailfrom=treblig.org; dkim=pass (2048-bit key) header.d=treblig.org header.i=@treblig.org header.b=XmbgW3S6; arc=none smtp.client-ip=46.235.229.95 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=treblig.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=treblig.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=treblig.org header.i=@treblig.org header.b="XmbgW3S6" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=treblig.org ; s=bytemarkmx; h=Content-Type:MIME-Version:Message-ID:Subject:From:Date:From :Subject; bh=l4/ObVuIt7UOD/QW6630dekGZj3RSJD8DWfo2+YTWOk=; b=XmbgW3S6VCsRsm46 1LTsab+aVcjrj1ts/Y3mnJOlWtNz6hHwWGQLpRBXWYAKAfQ1EqEhN139HehE19dhw8tFXRrsa8JKB l8SapWvl2IQcscJFHyOwbW6L9LrrGIOEzPmh8+S6VRgRi4UAiK448c+3ihAd9DeecaPV6F0sudqp9 NEgrWmmeg5u9PIJSXmfZpzCQVWCCHl+XYqUTtn8Qjzuad710o8matxi2MFlw0vNOWRi1rdOBEKAJp 0WW9p0LSHfvIoc0I66uZ8GJC2E9v+a83rSYbFSTAhikuk6TCHmComVdd0rSB4bYVjf7Rmg9dFkkwo mPj/FrCR90qp1lvTqg==; Received: from dg by mx.treblig.org with local (Exim 4.98.2) (envelope-from ) id 1vFjgV-00000001ajA-1fNO; Mon, 03 Nov 2025 01:48:39 +0000 Date: Mon, 3 Nov 2025 01:48:39 +0000 From: "Dr. David Alan Gilbert" To: Finn Thain Cc: Stan Johnson , mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, sam@ravnborg.org, benh@kernel.crashing.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, rdunlap@infradead.org, Cedar Maxwell Subject: Re: [PATCH v4] powerpc: Use shared font data Message-ID: References: <20230825142754.1487900-1-linux@treblig.org> <20108eef-b7cf-3f23-264a-5d97021f9ffa@linux-m68k.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20108eef-b7cf-3f23-264a-5d97021f9ffa@linux-m68k.org> X-Chocolate: 70 percent or better cocoa solids preferably X-Operating-System: Linux/6.12.48+deb13-amd64 (x86_64) X-Uptime: 01:43:41 up 7 days, 1:19, 2 users, load average: 0.02, 0.04, 0.00 User-Agent: Mutt/2.2.13 (2024-03-09) * Finn Thain (fthain@linux-m68k.org) wrote: > > On Sun, 2 Nov 2025, Dr. David Alan Gilbert wrote: > > > > > So I'm not a PPC person specifically; so lets see if the PPC people have > > any suggestions, but: > > > > a) Do you know if there's any way to recreate the same hang/works > > combination in qemu; I know it has a g3beige model but I don't know how > > to get something similar to your failing combo. > > > > I guess we could probably reproduce this in QEMU if the BootX bootloader > could be made to work there. In theory, 'qemu-system-ppc -M g3beige' might > work. > > > b) Can you get any diagnostics out of the prom on the mac? Like a PC > > or anything to have some idea where it hung? > > > > Well, that's the problem: if you enable the CONFIG_BOOTX_TEXT diagnostics, > the system hangs instead of printing stuff. If you disable the > CONFIG_BOOTX_TEXT diagnostics (in favour of serial diagnostics) the hang > goes away. Ah, a bug that doesn't like to be seen :-) > Anyway, I imagine that the problem with your patch was that it relies on > font data from a different (read only) section, which is unavailable for > some reason (MMU not fully configured yet?) > > So I've asked Stan to test a patch that simply removes the relevant > 'const' keywords. It's not a solution, but might narrow-down the search. I wonder if this is a compiler-flag-ism; I see arch/powerpc/kernel/Makefile has a pile of special flags, and for btext.o it has a -fPIC (as well as turning off some other flags). I wonder if bodging those in lib/fonts/Makefile for lib/fonts/font_sun8x16.c fixes it? But... this is data - there's no code is there - are any of those flags relevant for data only? > > c) Is this only the Powerbooks that are unhappy - are other Macs OK > > with this - if so, wth is the difference with a powerbook? Is it a > > different debian config or something? > > > > The BootX bootloader doesn't work on New World systems, which is probably > why we don't see this regression on anything newer than a Wallstreet. > > It's likely that other Old World systems are also affected, if they are > using BootX. We don't yet know whether the regression also affects Old > World systems using the iQUIK bootloader instead of BootX. OK, remember I don't think I've ever tried PPC via MacOS booting, so not familiar with it. Dave -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/