From patchwork Fri Jan 27 15:32:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 720780 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3v932p4wBjz9tkD for ; Sat, 28 Jan 2017 02:42:58 +1100 (AEDT) Received: from localhost ([::1]:46315 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX8fw-0005I2-6l for incoming@patchwork.ozlabs.org; Fri, 27 Jan 2017 10:42:56 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59620) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX8Vr-00012H-PK for qemu-devel@nongnu.org; Fri, 27 Jan 2017 10:32:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cX8Vr-00057b-0A for qemu-devel@nongnu.org; Fri, 27 Jan 2017 10:32:31 -0500 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:48311) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cX8Vq-00055y-QS for qemu-devel@nongnu.org; Fri, 27 Jan 2017 10:32:30 -0500 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.84_2) (envelope-from ) id 1cX8Vm-0003R6-Gh for qemu-devel@nongnu.org; Fri, 27 Jan 2017 15:32:26 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Date: Fri, 27 Jan 2017 15:32:12 +0000 Message-Id: <1485531137-2362-18-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1485531137-2362-1-git-send-email-peter.maydell@linaro.org> References: <1485531137-2362-1-git-send-email-peter.maydell@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:8b0:1d0::2 Subject: [Qemu-devel] [PULL 17/22] armv7m: FAULTMASK should be 0 on reset X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Michael Davidsaver For M profile CPUs, FAULTMASK should be 0 on reset, like PRIMASK. QEMU stores FAULTMASK in the PSTATE F bit, so (as with PRIMASK in the I bit) we have to clear these to undo the A profile default of 1. Update the comment accordingly and move it so that it's closer to the code it's referring to. Signed-off-by: Michael Davidsaver Reviewed-by: Alex Bennée Message-id: 1485285380-10565-10-git-send-email-peter.maydell@linaro.org [PMM: rewrote commit message, moved comments] Signed-off-by: Peter Maydell --- target/arm/cpu.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/target/arm/cpu.c b/target/arm/cpu.c index c804f59..0814f73 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -179,15 +179,16 @@ static void arm_cpu_reset(CPUState *s) /* SVC mode with interrupts disabled. */ env->uncached_cpsr = ARM_CPU_MODE_SVC; env->daif = PSTATE_D | PSTATE_A | PSTATE_I | PSTATE_F; - /* On ARMv7-M the CPSR_I is the value of the PRIMASK register, and is - * clear at reset. Initial SP and PC are loaded from ROM. - */ + if (arm_feature(env, ARM_FEATURE_M)) { uint32_t initial_msp; /* Loaded from 0x0 */ uint32_t initial_pc; /* Loaded from 0x4 */ uint8_t *rom; - env->daif &= ~PSTATE_I; + /* For M profile we store FAULTMASK and PRIMASK in the + * PSTATE F and I bits; these are both clear at reset. + */ + env->daif &= ~(PSTATE_I | PSTATE_F); /* The reset value of this bit is IMPDEF, but ARM recommends * that it resets to 1, so QEMU always does that rather than making @@ -195,6 +196,7 @@ static void arm_cpu_reset(CPUState *s) */ env->v7m.ccr = R_V7M_CCR_STKALIGN_MASK; + /* Load the initial SP and PC from the vector table at address 0 */ rom = rom_ptr(0); if (rom) { /* Address zero is covered by ROM which hasn't yet been