From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54297) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f98rt-0006BF-El for qemu-devel@nongnu.org; Thu, 19 Apr 2018 08:40:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f98rp-0005SW-AQ for qemu-devel@nongnu.org; Thu, 19 Apr 2018 08:40:53 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59194 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f98rp-0005SB-4f for qemu-devel@nongnu.org; Thu, 19 Apr 2018 08:40:49 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3JCaQOa034500 for ; Thu, 19 Apr 2018 08:40:48 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0b-001b2d01.pphosted.com with ESMTP id 2hetqwt05q-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Thu, 19 Apr 2018 08:40:48 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 19 Apr 2018 13:40:46 +0100 References: <1524054707-20663-1-git-send-email-thuth@redhat.com> <1524054707-20663-4-git-send-email-thuth@redhat.com> From: Viktor VM Mihajlovski Date: Thu, 19 Apr 2018 14:40:42 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Message-Id: <2d59a139-3bdd-4b4e-882c-5cf845488eda@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH v1 for-2.13 3/4] pc-bios/s390-ccw/net: Add support for pxelinux-style config files List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth , Christian Borntraeger , qemu-s390x@nongnu.org Cc: Cornelia Huck , qemu-devel@nongnu.org, Collin Walling On 19.04.2018 10:17, Thomas Huth wrote: > On 19.04.2018 09:41, Viktor VM Mihajlovski wrote: >> On 18.04.2018 14:31, Thomas Huth wrote: >>> Since it is quite cumbersome to manually create a combined kernel with >>> initrd image for network booting, we now support loading via pxelinux >>> configuration files, too. In these files, the kernel, initrd and command >>> line parameters can be specified seperately, and the firmware then takes >>> care of glueing everything together in memory after the files have been >>> downloaded. [...] >>> +static int net_try_direct_tftp_load(filename_ip_t *fn_ip) >>> +{ >>> + int rc; >>> + void *baseaddr = (void *)0x2000; /* Load right after the low-core */ >>> + >>> + rc = tftp_load(fn_ip, baseaddr, KERNEL_MAX_SIZE - (long)baseaddr); >>> + >>> + if (rc > 0 && rc < sizeof(cfgbuf) - 1) { >>> + /* Check whether it is a configuration file instead of a kernel */ >> That's interesting because treating the bootfile as pxe-ish config is >> what DPM does. Which means that with this change the processor >> architecture type 0x1f (Basic) will turn into a superset of 0x20 >> (Extended). > > Is there any reference available what "basic" and "extended" exactly > mean? I just know that there are these two values registered by you at > the IANA: > > https://www.iana.org/assignments/dhcpv6-parameters/dhcpv6-parameters.xhtml#processor-architecture > > ... but I haven't seen a description of the differences of these two > values yet. > Yep, the IANA stuff is pretty terse for all architectures. In a nutshell: 0x1f is standard DHCP-based boot (bootfile is a single executable binary) and 0x20 serves a pxe-style config file instead. In fact, "processor architecture identifier" is a misnomer, as it describes a pair of processor architecture and firmware. Since the QEMU firmware has two significant extensions now (insfile and direct config file loading), it might be worthwhile to add a new identifier value (say s390 QEMU PC-BIOS or similar) announcing the new capabilities, so that a boot server admin can setup her system accordingly. >> I guess this should be documented somewhere(TM) to avoid >> confusion. > > I plan to update https://wiki.qemu.org/Features/S390xNetworkBoot once > the patches have been merged upstream. > sounds good. [...] -- Regards, Viktor Mihajlovski