src/arch/x86/gdt.hpp

Idź do dokumentacji tego pliku.

/*define for src/arch/x86/gdt.cpp*/
#ifndef _CORE_X86_GDT_HPP
#define _CORE_X86_GDT_HPP

namespace Arch {
namespace x86 {
namespace GDT {


void init();    /*init gdt*/

const uint32 DEF_MAXSEGMS = 16;         //we won't be needing more than 16 segments

/*the values of certain gdt selectors*/
extern uint32 code_sel_kernel;
extern uint32 data_sel_kernel;
extern uint32 code_sel_user;
extern uint32 data_sel_user;
extern uint32 tss_sel_kernel;
extern uint32 tss_sel_kernel_df;        //for double faults
extern uint32 tss_sel_kernel_sf;        //for stack faults

/*tss' in system*/
extern "C" struct tss_t kernel_tss;             /*kernel tss*/
extern tss_t kernel_tss_df;             /*kernel tss for double fault handling*/
extern tss_t kernel_tss_sf;             /*kernel tss for stack fault handling*/
extern char temp_tss_stack[0x100];      /*initial stack in the esp, just in case*/

struct gdt_entry_t
 {
        short s_limit0_15;
        short s_base0_15;
        char s_base16_23;
        char s_attr;
        char s_limit16_19;
        char s_base24_31;
 }  __attribute__ ((packed));

struct gdtr_t
 {
        short s_limit;
        gdt_entry_t *s_base;
 } __attribute__ ((packed));

class gdt_t
 {
public:
        gdtr_t gdtr;
        gdt_entry_t gdt[DEF_MAXSEGMS];
        short segm_count;
public:
        void init();
        short new_sel(int limit, int base, char attr, char flags);
        void lgdt();
 };

extern gdt_t kernel_gdt;        //the handle for the descriptors

struct tss_t
 {
        uint16  backlink, __blh;
        uint32  esp0;
        uint16  ss0, __ss0h;
        uint32  esp1;
        uint16  ss1, __ss1h;
        uint32  esp2;
        uint16  ss2, __ss2h;
        uint32  cr3;
        uint32  eip;
        uint32  eflags;
        uint32  eax, ecx, edx, ebx;
        uint32  esp, ebp, esi, edi;
        uint16  es, __esh;
        uint16  cs, __csh;
        uint16  ss, __ssh;
        uint16  ds, __dsh;
        uint16  fs, __fsh;
        uint16  gs, __gsh;
        uint16  ldt, __ldth;
        uint16  trace, bitmap;
 } __attribute__ ((packed));


   };   /*namespace GDT*/
  };    /*namespace x86*/
 };     /*namespace Arch*/

#endif

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