From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IcTH1-0002aP-V2 for qemu-devel@nongnu.org; Mon, 01 Oct 2007 17:57:56 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IcTH0-0002Zl-98 for qemu-devel@nongnu.org; Mon, 01 Oct 2007 17:57:55 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IcTH0-0002Zi-4N for qemu-devel@nongnu.org; Mon, 01 Oct 2007 17:57:54 -0400 Received: from phoenix.bawue.net ([193.7.176.60] helo=mail.bawue.net) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IcTGz-0004IJ-Bs for qemu-devel@nongnu.org; Mon, 01 Oct 2007 17:57:53 -0400 Date: Mon, 1 Oct 2007 22:57:41 +0100 From: Thiemo Seufer Subject: Re: [Qemu-devel] qemu/pc-bios ppc_rom.bin Message-ID: <20071001215741.GA16772@networkno.de> References: <47009C20.7000809@qumranet.com> <1191222768.16080.0.camel@bxl-cdrw.bxl.cronos-technologies.com> <36FA7E24-859B-4033-BB37-2C8453D81677@web.de> <1191253624.3514.56.camel@jma4.dev.netgem.com> <20071001185627.GI13317@networkno.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: l_indien@magic.fr, qemu-devel@nongnu.org Blue Swirl wrote: [snip] > > > Qemu is not also aimed for 100% accurate emulation of the hardware. > > > There are no caches or cycle counters and hardware devices run > > > unrealistically fast from CPU standpoint. Emulating performance > > > counters or the errata the most CPUs have would be extremely > > > difficult. I doubt Qemu CPU emulation can ever pass POST of real > > > BIOSes. > > > > I am working on making the Malta emulation boot a unaltered YAMON > > image. I don't see why a PC BIOS would be harder to accomodate. > > Emulating microcode, or firmware blobs loaded to misc devices. Think > writing a BIOS for Transmeta, Writing the emulation for a transmeta is IMHO more challenging than writing the "BIOS". Btw, if you are interested in the x86 mode, you can handle the transmeta just as a x86 variant (with a much more standard BIOS). > Alpha or a SoC. Writing "Firmware for a SoC" is part of my dayjob. > > > Real BIOSes are also closed source, proprietary binary blobs. > > > > At least YAMON, CFE and PMON are not closed source. YAMON has a funny > > license which - I hope - will change. > > > > > Making open source BIOSes a viable alternative is in my opinion a much > > > more important goal. > > > > The one doesn't exclude the other. That said, I regard the ability to > > boot unaltered real-world firmare as an important test of the quality > > of a system emulation. > > Maybe. The CPU probes for cacheline size, checks for errata #42 vs > #45, reads debug registers, attempts to identify the bus speed by > comparing I/O access times, tries to verify the system using a TPM and > fails all cases. What can you do? Improve the emulation to handle at least one probing path. Thiemo