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contiki/cpu/x86/init/common/gdt.h

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x86: Initialize Global Descriptor Table This patch adds code to initialize the Global Descriptor Table. For simplicity, the memory is organized following the flat model. Thus, memory appears to Contiki as a single, continuous address space. Code, data, and stack are all contained in this address space (so called linear address space). The macros to manipulate bits from segment descriptor and the set_descriptor() helper are based on the ones described in [1]. [1] http://wiki.osdev.org/GDT_Tutorial
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/*
x86: Add support for (paging-based) protection domains This patch implements a simple, lightweight form of protection domains using a pluggable framework. Currently, the following plugin is available: - Flat memory model with paging. The overall goal of a protection domain implementation within this framework is to define a set of resources that should be accessible to each protection domain and to prevent that protection domain from accessing other resources. The details of each implementation of protection domains may differ substantially, but they should all be guided by the principle of least privilege. However, that idealized principle is balanced against the practical objectives of limiting the number of relatively time-consuming context switches and minimizing changes to existing code. For additional information, please refer to cpu/x86/mm/README.md. This patch also causes the C compiler to be used as the default linker and assembler.
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* Copyright (C) 2015-2016, Intel Corporation. All rights reserved.
x86: Initialize Global Descriptor Table This patch adds code to initialize the Global Descriptor Table. For simplicity, the memory is organized following the flat model. Thus, memory appears to Contiki as a single, continuous address space. Code, data, and stack are all contained in this address space (so called linear address space). The macros to manipulate bits from segment descriptor and the set_descriptor() helper are based on the ones described in [1]. [1] http://wiki.osdev.org/GDT_Tutorial
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*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef GDT_H
#define GDT_H
x86: Add support for (paging-based) protection domains This patch implements a simple, lightweight form of protection domains using a pluggable framework. Currently, the following plugin is available: - Flat memory model with paging. The overall goal of a protection domain implementation within this framework is to define a set of resources that should be accessible to each protection domain and to prevent that protection domain from accessing other resources. The details of each implementation of protection domains may differ substantially, but they should all be guided by the principle of least privilege. However, that idealized principle is balanced against the practical objectives of limiting the number of relatively time-consuming context switches and minimizing changes to existing code. For additional information, please refer to cpu/x86/mm/README.md. This patch also causes the C compiler to be used as the default linker and assembler.
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#include "gdt-layout.h"
#include "prot-domains.h"
#include "segmentation.h"
extern segment_desc_t gdt[];
extern int _ebss_gdt_addr;
#define GDT_IDX_OF_DESC(ptr) \
((((uintptr_t)(ptr)) - ((uintptr_t)&gdt))/ \
sizeof(segment_desc_t))
/**
* \brief Compute the selector for a GDT entry allocated somewhere besides gdt.c.
* \param ptr Pointer to GDT descriptor.
* \param rpl Requested Privilege Level.
*/
#define GDT_SEL_OF_DESC(ptr, rpl) GDT_SEL(GDT_IDX_OF_DESC(ptr), rpl)
#define ATTR_BSS_GDT __attribute__((section(".gdt_bss")))
#define ATTR_BSS_GDT_START __attribute__((section(".gdt_bss_start")))
void gdt_copy_desc_change_dpl(unsigned int dest_idx,
unsigned int src_idx,
unsigned dpl);
void gdt_init(void) ATTR_CODE_BOOT;
void gdt_insert(unsigned int idx, segment_desc_t desc);
void gdt_lookup(unsigned int idx, segment_desc_t *desc);
x86: Initialize Global Descriptor Table This patch adds code to initialize the Global Descriptor Table. For simplicity, the memory is organized following the flat model. Thus, memory appears to Contiki as a single, continuous address space. Code, data, and stack are all contained in this address space (so called linear address space). The macros to manipulate bits from segment descriptor and the set_descriptor() helper are based on the ones described in [1]. [1] http://wiki.osdev.org/GDT_Tutorial
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#endif /* GDT_H */
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