From patchwork Thu Apr 30 00:23:08 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sandra Loosemore X-Patchwork-Id: 6494 Received: (qmail 96433 invoked by alias); 30 Apr 2015 00:24:16 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 96420 invoked by uid 89); 30 Apr 2015 00:24:15 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 30 Apr 2015 00:24:14 +0000 Received: from svr-orw-fem-03.mgc.mentorg.com ([147.34.97.39]) by relay1.mentorg.com with esmtp id 1YncGx-0001H9-16 from Sandra_Loosemore@mentor.com ; Wed, 29 Apr 2015 17:24:11 -0700 Received: from [IPv6:::1] (147.34.91.1) by svr-orw-fem-03.mgc.mentorg.com (147.34.97.39) with Microsoft SMTP Server id 14.3.224.2; Wed, 29 Apr 2015 17:24:10 -0700 Message-ID: <554175EC.8060704@codesourcery.com> Date: Wed, 29 Apr 2015 18:23:08 -0600 From: Sandra Loosemore User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: , Yao Qi Subject: [patch v2 1/5, nios2] revert to using "trap 31" for breakpoints References: <554172F8.2020108@codesourcery.com> In-Reply-To: <554172F8.2020108@codesourcery.com> This is a revised version of the patch previously posted at https://sourceware.org/ml/gdb-patches/2015-04/msg00905.html I've made the requested change to the comment text. OK to commit? -Sandra diff --git a/gdb/nios2-tdep.c b/gdb/nios2-tdep.c index 08f2034..988b9fc 100644 --- a/gdb/nios2-tdep.c +++ b/gdb/nios2-tdep.c @@ -1189,7 +1189,15 @@ nios2_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc) return nios2_analyze_prologue (gdbarch, start_pc, start_pc, &cache, NULL); } -/* Implement the breakpoint_from_pc gdbarch hook. */ +/* Implement the breakpoint_from_pc gdbarch hook. + + The Nios II ABI for Linux says: "Userspace programs should not use + the break instruction and userspace debuggers should not insert + one." and "Userspace breakpoints are accomplished using the trap + instruction with immediate operand 31 (all ones)." + + So, we use "trap 31" consistently as the breakpoint on bare-metal + as well as Linux targets. */ static const gdb_byte* nios2_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr, @@ -1198,11 +1206,11 @@ nios2_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr, enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); unsigned long mach = gdbarch_bfd_arch_info (gdbarch)->mach; - /* R1 break encoding: - ((0x1e << 17) | (0x34 << 11) | (0x1f << 6) | (0x3a << 0)) - 0x003da7fa */ - static const gdb_byte r1_breakpoint_le[] = {0xfa, 0xa7, 0x3d, 0x0}; - static const gdb_byte r1_breakpoint_be[] = {0x0, 0x3d, 0xa7, 0xfa}; + /* R1 trap encoding: + ((0x1d << 17) | (0x2d << 11) | (0x1f << 6) | (0x3a << 0)) + 0x003b6ffa */ + static const gdb_byte r1_breakpoint_le[] = {0xfa, 0x6f, 0x3b, 0x0}; + static const gdb_byte r1_breakpoint_be[] = {0x0, 0x3b, 0x6f, 0xfa}; *bp_size = NIOS2_OPCODE_SIZE; if (byte_order_for_code == BFD_ENDIAN_BIG) return r1_breakpoint_be;