memory.h

一个用于学习的操作系统

/*文件名: memory.h
  说明:   页级内存管理函数
  作者:   marsinfan
  日期:   2005/12/20
*/
#ifndef _memory_h_
#define _memory_h_

#include <fairysky/types.h>

#define PAGE_SIZE 4096
#define _1M_SIZE 0X00100000
#define PAGE_DIR 0xC0010000     //进程0的页目录地址

#define PAGE_PRESENT    0x001
#define PAGE_RW        0x002
#define PAGE_USER    0x004
#define PAGE_PWT    0x008    /* 486 only - not used currently */
#define PAGE_PCD    0x010    /* 486 only - not used currently */
#define PAGE_ACCESSED    0x020
#define PAGE_DIRTY    0x040
#define PAGE_COW    0x200    /* implemented in software (one of the AVL bits) */

#define PAGE_PRIVATE    (PAGE_PRESENT | PAGE_RW | PAGE_USER | PAGE_ACCESSED | PAGE_COW)
#define PAGE_SHARED    (PAGE_PRESENT | PAGE_RW | PAGE_USER | PAGE_ACCESSED)
#define PAGE_COPY    (PAGE_PRESENT | PAGE_USER | PAGE_ACCESSED | PAGE_COW)
#define PAGE_READONLY    (PAGE_PRESENT | PAGE_USER | PAGE_ACCESSED)
#define PAGE_TABLE    (PAGE_PRESENT | PAGE_RW | PAGE_USER | PAGE_ACCESSED)

extern s32 put_page(addr_t addr);
extern s32 copy_page_table(u32 to, u32 from);
extern void do_wp_page(u32 addr);
extern void do_no_page(u32 addr);
extern int get_free_page();
extern int free_page(u32 addr);

#define MAX_MEM 16

typedef struct mem_info {
    u8 used;
} MEM_INFO;

extern MEM_INFO *mem_map;


//用刷新cr3的方法来刷新TLB
#define __flush_tlb()                            \
    do {                                \
        unsigned int tmpreg;                    \
        __asm__ __volatile__(                    \
        "movl %%cr3, %0;              \n"        \
        "movl %0, %%cr3;  # flush TLB \n"        \
        : "=r" (tmpreg)                    \
        :: "memory");                    \
        } while (0)


#endif