From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:49463) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h2K8J-00013I-Qv for qemu-devel@nongnu.org; Fri, 08 Mar 2019 13:22:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h2K8I-0000Fz-VW for qemu-devel@nongnu.org; Fri, 08 Mar 2019 13:22:11 -0500 Received: from mail-oi1-x242.google.com ([2607:f8b0:4864:20::242]:36722) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1h2K8I-0000FJ-OV for qemu-devel@nongnu.org; Fri, 08 Mar 2019 13:22:10 -0500 Received: by mail-oi1-x242.google.com with SMTP id t206so16587423oib.3 for ; Fri, 08 Mar 2019 10:22:10 -0800 (PST) MIME-Version: 1.0 References: <1550029560-30530-1-git-send-email-sandra@codesourcery.com> <1550029560-30530-3-git-send-email-sandra@codesourcery.com> <7d4097aa-4888-82f6-3e4e-eeeb8de9f55b@codesourcery.com> In-Reply-To: From: Peter Maydell Date: Fri, 8 Mar 2019 18:21:58 +0000 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] [PATCH v5 2/2] Add Nios II semihosting support. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Sandra Loosemore Cc: QEMU Developers , Marek Vasut On Fri, 8 Mar 2019 at 17:01, Sandra Loosemore wrote: > > On 3/8/19 9:04 AM, Peter Maydell wrote: > > Thanks. So who "owns" this ABI (ie has the authority to change > > it and should be the end documenting it)? How many projects or > > bits of software are implementing either end of it? > > Going back in ancient history, I implemented the m68k version in > libgloss in 2006 to support a hardware debug stub that CodeSourcery was > also providing at that time. We later moved the runtime side of it into > target-agnostic code in an internal library, so when it came time to do > a similar JTAG debug stub for bare-metal Nios II hardware testing in > 2012, we re-used our existing code for both library and debug stub. > Later Altera implemented the same protocol in some proprietary > simulators they provided to us, and more recently we wrote these patches > to add it to QEMU. We've shifted away from hardware testing and no > longer use the original debug stub now. > > > If we decide that QEMU owns the spec we can put the documentation > > into docs/specs/. > > Making QEMU the "owner" of the ABI seems a little peculiar to me since > it is only one client among several, and is a latecomer too. I think > libgloss would make a little more sense. OTOH, I have no problem with > making the documentation part of QEMU. Thanks for the backstory. I agree that if QEMU is just one of multiple implementations then it's not a great place to hold the specification. Either libgloss, or I suppose in theory Altera as the owner of the architecture could bless the specification and host it... -- PMM