From 3e52d9fb3328258139f3523175d28ae8f11af702 Mon Sep 17 00:00:00 2001 From: Maximilian Stein Date: Mon, 29 Jan 2018 12:21:32 +0100 Subject: arch-x86: Granularity bit and segment limit If set, the granularity bit indicates that the segment limit of segment descriptors shall be interpreted as number of 4K blocks rather than bytes. The high part (bit 48 to 51) of segment descriptor limits is only 4 bits wide while the low part (bit 0 to 15) spans 16 bits. Change-Id: Ie386224ca815275fdb31498fe68310ed9c62cc87 Reviewed-on: https://gem5-review.googlesource.com/7601 Reviewed-by: Gabe Black Maintainer: Gabe Black --- src/arch/x86/system.cc | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/arch/x86/system.cc b/src/arch/x86/system.cc index ecde8366a..69e013f9b 100644 --- a/src/arch/x86/system.cc +++ b/src/arch/x86/system.cc @@ -1,5 +1,6 @@ /* * Copyright (c) 2007 The Hewlett-Packard Development Company + * Copyright (c) 2018 TU Dresden * All rights reserved. * * The license below extends only to copyright in the software and shall @@ -35,6 +36,7 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Authors: Gabe Black + * Maximilian Stein */ #include "arch/x86/system.hh" @@ -67,6 +69,8 @@ X86ISA::installSegDesc(ThreadContext *tc, SegmentRegIndex seg, seg == SEGMENT_REG_TSL || seg == SYS_SEGMENT_REG_TR; uint64_t limit = desc.limitLow | (desc.limitHigh << 16); + if (desc.g) + limit = (limit << 12) | mask(12); SegAttr attr = 0; @@ -155,8 +159,8 @@ X86System::initState() initDesc.d = 0; // operand size initDesc.g = 1; // granularity initDesc.s = 1; // system segment - initDesc.limitHigh = 0xFFFF; - initDesc.limitLow = 0xF; + initDesc.limitHigh = 0xF; + initDesc.limitLow = 0xFFFF; initDesc.baseHigh = 0x0; initDesc.baseLow = 0x0; -- cgit v1.2.3