From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=2a00:1450:4864:20::444; helo=mail-wr1-x444.google.com; envelope-from=leif.lindholm@linaro.org; receiver=edk2-devel@lists.01.org Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 6FF472119AC39 for ; Wed, 12 Dec 2018 03:30:13 -0800 (PST) Received: by mail-wr1-x444.google.com with SMTP id j2so17348672wrw.1 for ; Wed, 12 Dec 2018 03:30:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3pvrzEwRLR5kfK5OuPYnmbSAx9FVooolF9gsSpRty/8=; b=j3N/cGyktIZpewVvISGwCOzoONN7ErRdCy8y0UBei9L5V+F7eImcXTCWPjQ2YiPE26 6ecVmNoYO4V/Q+6PPkJl/76s2Q0Ri/TyoTo4ZotnY7YXAEgFiMV+dFyHjYL93OUCmV9c wQJ8up+IO1YNZI53x1P0nMLVsc+yWiqiKWxyQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=3pvrzEwRLR5kfK5OuPYnmbSAx9FVooolF9gsSpRty/8=; b=HSV9TpmGkgs/Vug+GuSrlqWb3FWQYXaBjURTlAH+smwrCKpEdKFipMzC+AJsqrXwLu /wCTN9rbiQqooMgQJ499CqsRceaHIF59JtC7JRzwbJSOkUGEHuYdm109kODswulYYpYf YZMeZzaMyV7Km2LdYl5tnl6wy82KVCuvZyAbFlTxob9G+0U27YQHwpDdsgv25Zyf906f jYZnZTrwNDlVuAt4Egk/qfSEmT2nHTAYnWmNER4SJ4hyJmo6JfCmJkVXpRpJAhepbMMY VuZzvWjE+02V9AZ09MP4pQ2/hCjsSfCktsgK7cVK0Ai/mZ4ONu9bbF0GSXJIQMZQtLoT wE3g== X-Gm-Message-State: AA+aEWYwzTYUpm4vfdy9Q0J3ryXRpNYYCP960l4oiwWmRHrv1ic3vSPC imiQOoJ0sgvLuoKe6vMsf9/b1VDUY9Q= X-Google-Smtp-Source: AFSGD/V334kDbflvm2g5IUL4kbNuGV9AeC0RVNU21jnfdlvBZACJYzA/mV0wegkpusF/WH3wvMskaQ== X-Received: by 2002:a5d:6684:: with SMTP id l4mr18641629wru.154.1544614211846; Wed, 12 Dec 2018 03:30:11 -0800 (PST) Received: from bivouac.eciton.net (bivouac.eciton.net. [2a00:1098:0:86:1000:23:0:2]) by smtp.gmail.com with ESMTPSA id j8sm4597313wmd.0.2018.12.12.03.30.10 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 12 Dec 2018 03:30:11 -0800 (PST) Date: Wed, 12 Dec 2018 11:30:09 +0000 From: Leif Lindholm To: Ard Biesheuvel Cc: edk2-devel@lists.01.org Message-ID: <20181212113009.vmsv37swaui3z4os@bivouac.eciton.net> References: <20181212091211.13258-1-ard.biesheuvel@linaro.org> MIME-Version: 1.0 In-Reply-To: <20181212091211.13258-1-ard.biesheuvel@linaro.org> User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [PATCH] EmbeddedPkg/GdbDebugAgent ARM: use modern dialect for ldm/stm instructions X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Dec 2018 11:30:14 -0000 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 12, 2018 at 10:12:11AM +0100, Ard Biesheuvel wrote: > Clang does not like the legacy 32-bit assembler syntax used in the > gdbstub exception handling routines, so update them to something > more fashionable. > > So switch the order of the conditional suffix Yes, this is essentially a bugfix. The syntax change predates ARM's involvement in EDK2. > and the increment/decrement > specifier, and use decrement-after (da) and increment-before (ib) as > appropriate for an empty descending stack. But I very much prefer the FA/FD/EA/ED syntax. It gives symmetry, which helps me a lot when dealing with 7-character mnemonics. These aliases are also defined in the ARM ARM and won't be going away. / Leif > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Ard Biesheuvel > --- > EmbeddedPkg/Library/GdbDebugAgent/Arm/ExceptionSupport.ARMv6.S | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/EmbeddedPkg/Library/GdbDebugAgent/Arm/ExceptionSupport.ARMv6.S b/EmbeddedPkg/Library/GdbDebugAgent/Arm/ExceptionSupport.ARMv6.S > index df1543a6d242..924578c7af2f 100644 > --- a/EmbeddedPkg/Library/GdbDebugAgent/Arm/ExceptionSupport.ARMv6.S > +++ b/EmbeddedPkg/Library/GdbDebugAgent/Arm/ExceptionSupport.ARMv6.S > @@ -57,6 +57,7 @@ GCC_ASM_EXPORT(AsmCommonExceptionEntry) > GCC_ASM_EXPORT(GdbExceptionHandler) > > .text > +.syntax unified > .align 3 > > > @@ -198,9 +199,9 @@ ASM_PFX(AsmCommonExceptionEntry): > and R3, R1, #0x1f @ Check CPSR to see if User or System Mode > cmp R3, #0x1f @ if ((CPSR == 0x10) || (CPSR == 0x1df)) > cmpne R3, #0x10 @ > - stmeqed R2, {lr}^ @ save unbanked lr > + stmdaeq R2, {lr}^ @ save unbanked lr > @ else > - stmneed R2, {lr} @ save SVC lr > + stmdane R2, {lr} @ save SVC lr > > > ldr R5, [SP, #0x58] @ PC is the LR pushed by srsfd > @@ -245,9 +246,9 @@ GdbExceptionHandler ( > and R1, R1, #0x1f @ Check to see if User or System Mode > cmp R1, #0x1f @ if ((CPSR == 0x10) || (CPSR == 0x1f)) > cmpne R1, #0x10 @ > - ldmeqed R2, {lr}^ @ restore unbanked lr > + ldmibeq R2, {lr}^ @ restore unbanked lr > @ else > - ldmneed R3, {lr} @ restore SVC lr, via ldmfd SP!, {LR} > + ldmibne R3, {lr} @ restore SVC lr, via ldmfd SP!, {LR} > > ldmfd SP!,{R0-R12} @ Restore general purpose registers > @ Exception handler can not change SP > -- > 2.19.2 >