From nobody Mon Jan 10 22:43:13 2022 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id DA4C41941195; Mon, 10 Jan 2022 22:43:16 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4JXpkr4FnZz4mpX; Mon, 10 Jan 2022 22:43:16 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from [10.0.1.4] (ralph.baldwin.cx [66.234.199.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jhb) by smtp.freebsd.org (Postfix) with ESMTPSA id E21562D531; Mon, 10 Jan 2022 22:43:15 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Message-ID: Date: Mon, 10 Jan 2022 14:43:13 -0800 List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: git: d6c0538dae8d - main - ddb: Remove SOFTWARE_SSTEP support Content-Language: en-US To: Warner Losh Cc: Warner Losh , src-committers , dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org References: <202201071627.207GRsGX062055@gitrepo.freebsd.org> <45275428-75e2-aaae-bed3-e5e84b39e17c@FreeBSD.org> From: John Baldwin In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1641854596; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HsuCbMuHb9XzTb0hAZpd62Xq8xxxt/ZxXfkAtLCYrHk=; b=g1abHK6K32rONQYP1W59jivjWQQqVJq88L5idjrc8NvGT3Ta8+mo92x25y6BLXGz5+k7Ea 2PeNSIKJtpzB2Ro5ftw5ZNeqFT9IxeqE4bL5ZidJVCa3JgTNithqXkJtNtSmpFu+wFgURj 7BZlWvVK2s1P2Jhrv6Yw5ZhyKuTwMynRxTf0c9iir72Fvr8J7dPCkftk0vqPLbbsVy4DXl g3W3Xqd8LjKFxX5BzjVcsAgki6Gs8LTsFLZ7om+mgYtyLzXebCEJtE+yOv4GRuOw+pyHix TECo2Wesd3jINk2+XlRXWEocsBoasPB22B2z1Cxup0qb17y61zWrB4DT8MnD3w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1641854596; a=rsa-sha256; cv=none; b=HHeVh3js5iOsLZjTOKBXMcQLIoJ5xRf7xnMQgRtlw1AoFkwZrYbrkYLQXh9PtiaglnoufB YtTnaPtCPIxZYlEvaUGOG7HEKYUpXRrmFa4k2GloQuWxB0ZqAGxxsA3fgOS8VO3HTga/km UMEX18FJYDoRkPn/O/SgY2Entm4INZw3FKDeoD8o7sKlynvhratToNbclZcv/kbnlFCqCV gljGA1ErbDanUaTaCDIRxQx9RGWfb0/QQPtS+xx61WSFanUNxJHumnKgqxi199PT15rImS 49Hh26WssB+gsJp+8JuKj+4RaU+Tt4GbQ+P/mXMY+XCcMmNvZBgtuHfYJ49MTg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N On 1/10/22 1:14 PM, Warner Losh wrote: > On Mon, Jan 10, 2022 at 12:48 PM John Baldwin wrote: > >> On 1/7/22 8:27 AM, Warner Losh wrote: >>> The branch main has been updated by imp: >>> >>> URL: >> https://cgit.FreeBSD.org/src/commit/?id=d6c0538dae8d138219dfd051994a44c50e741212 >>> >>> commit d6c0538dae8d138219dfd051994a44c50e741212 >>> Author: Warner Losh >>> AuthorDate: 2022-01-07 16:25:33 +0000 >>> Commit: Warner Losh >>> CommitDate: 2022-01-07 16:25:33 +0000 >>> >>> ddb: Remove SOFTWARE_SSTEP support >>> >>> It was needed for mips only, and only kinda sorta worked for mips. >> It >>> can be brought back if we grow another architecture that need it. >>> >>> Sponsored by: Netflix >> >> RISC-V would need it in theory (no hardware single step), but no one has >> felt the >> need to implement the backend support for it. I think 32-bit arm doesn't >> support >> hardware single step either (but again, no one has bothered to add the >> backend >> support). >> > > Generally, I agree with these thoughts. I went ahead with the removal > because I > knew it would be easy to bring back, even years from now should someone[tm] > have an implementation for those platforms (though I thought 32-bit arm did > have > single step in hardware). > > Should I put it back? Or should we wait until someone shows up with support > for > a supported platform? I think the latter. I don't know that I've ever used single step in DDB on any platform myself. In my experience, using a gdb stub in QEMU or via JTAG or the like is a much better experience for debugging boot-time initialization. -- John Baldwin