From a8968330aff45e0b8cf278f49fa337d5fcb9bfd8 Mon Sep 17 00:00:00 2001 From: Alex AUVOLAT Date: Fri, 28 Mar 2014 17:09:15 +0100 Subject: Import and compile code for article 6.5 --- sos-code-article6.5/hwcore/segment.h | 70 ++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 sos-code-article6.5/hwcore/segment.h (limited to 'sos-code-article6.5/hwcore/segment.h') diff --git a/sos-code-article6.5/hwcore/segment.h b/sos-code-article6.5/hwcore/segment.h new file mode 100644 index 0000000..4487216 --- /dev/null +++ b/sos-code-article6.5/hwcore/segment.h @@ -0,0 +1,70 @@ +/* Copyright (C) 2004 The SOS Team + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + USA. +*/ +#ifndef _SOS_HWSEGS_H_ +#define _SOS_HWSEGS_H_ + +/** + * @file segments.h + * + * Global and local (GDT/LDT) segment descriptor definition and + * structure. These segments map virtual addresses (ie + * data/instruction addresses, relative to these segment descriptors) + * to linear addresses (ie addresses in the paged-memory space). + * + * @see Intel x86 doc, vol 3 chapter 3. + */ + + +/* + * Global segment selectors (GDT) for SOS/x86. + * + * @see gdt.h + */ +#define SOS_SEG_NULL 0 /* NULL segment, unused by the procesor */ +#define SOS_SEG_KCODE 1 /* Kernel code segment */ +#define SOS_SEG_KDATA 2 /* Kernel data segment */ + + +#ifndef ASM_SOURCE +/** + * Helper macro that builds a segment register's value + */ +#define SOS_BUILD_SEGMENT_REG_VALUE(desc_privilege,in_ldt,seg_index) \ + ( (((desc_privilege) & 0x3) << 0) \ + | (((in_ldt)?1:0) << 2) \ + | ((seg_index) << 3) ) +#else +/* + * Assembler-compliant version. + * + * Caution: In assembler code, "in_ldt" MUST be either 1 or 0, nothing + * else. + */ +#define SOS_BUILD_SEGMENT_REG_VALUE(desc_privilege,in_ldt,seg_index) \ + ( (((desc_privilege) & 0x3) << 0) \ + | ((in_ldt & 1) << 2) \ + | ((seg_index) << 3) ) +#endif + + +/* + * Local segment selectors (LDT) for SOS/x86 + */ +/* None */ + +#endif /* _SOS_HWSEGS_H_ */ -- cgit v1.2.3