e820.h

一个用于学习的操作系统

/*
 * structures and definitions for the int 15, ax=e820 memory map
 * scheme.
 *
 * In a nutshell, arch/i386/boot/setup.S populates a scratch table
 * in the empty_zero_block that contains a list of usable address/size
 * duples.   In arch/i386/kernel/setup.c, this information is
 * transferred into the e820map, and in arch/i386/mm/init.c, that
 * new information is used to mark pages reserved or not.
 *
 */
#ifndef __E820_HEADER
#define __E820_HEADER

#define E820MAP    0x2d0        /* our map */
#define E820MAX    128        /* number of entries in E820MAP */
#define E820NR    0x1e8        /* # entries in E820MAP */

#define E820_RAM    1
#define E820_RESERVED    2
#define E820_ACPI    3 /* usable as RAM once ACPI tables have been read */
#define E820_NVS    4

#define HIGH_MEMORY    (1024*1024)

#ifndef __ASSEMBLY__

struct e820entry {
    unsigned long long addr;    /* start of memory segment */
    unsigned long long size;    /* size of memory segment */
    unsigned long type;            /* type of memory segment */
} __attribute__((packed));

struct e820map {
    int nr_map;
    struct e820entry map[E820MAX];
}__attribute__((packed));

extern struct e820map e820;
#endif/*!__ASSEMBLY__*/

#endif/*__E820_HEADER*/