system.h

一个用于学习的操作系统

/*文件名: system.h
  说明:   系统指令接口
  作者:   Linus Torvalds
  日期:   2005/12/20
*/

#define set_trap_gate(index, fun_addr)    \
    setup_IDT_entry(&idt[index], 0x08, (u32) & fun_addr, ACS_INT, 0)


#define move_to_user_mode(esp) \
    __asm__ __volatile__ (    \
        "pushl $0x23\n\t" \
        "pushl %%eax\n\t" \
        "pushfl\n\t" \
        "pushl $0x1B\n\t" \
        "pushl $1f\n\t" \
        "iret\n" \
        "1:\tmovl $0x23, %%eax\n\t" \
        "mov %%ax,%%ds\n\t" \
        "mov %%ax,%%es\n\t" \
        "mov %%ax,%%fs\n\t" \
        "mov %%ax,%%gs" \
        ::"a"(esp)    \
        )


#define sti() __asm__ __volatile__ ("sti"::)
#define cli() __asm__ __volatile__ ("cli"::)
#define nop() __asm__ __volatile__ ("nop"::)

#define iret() __asm__ __volatile__ ("iret"::)

#define lidt(_idt)  \
    __asm__ __volatile__ ( \
        "lidtl  (%%ebx)" \
        :   \
        :"b"(_idt)  \
        )

#define load_fs(value) \
    __asm__ __volatile__( \
        "movw     %%ax, %%fs\n\t" \
        ::"a" (value) \
        )

#define load_gs(value) \
    __asm__ __volatile__( \
        "movw     %%ax, %%gs\n\t" \
        ::"a" (value) \
        )

#define ltr(value) \
    __asm__ __volatile__( \
        "ltrw     %%ax\n\t" \
        ::"a" (value) \
        )

#define lldt(value) \
    __asm__ __volatile__( \
        "lldtw     %%ax\n\t" \
        ::"a" (value) \
        )

#define lgdt(_idt)  \
    __asm__ __volatile__ ( \
        "lgdtl  (%%ebx)" \
        :   \
        :"b"(_idt)  \
        )