#include "type.h"
#include "const.h"
#include "protect.h"
#include "string.h"
#include "proto.h"
#include "proc.h"
#include "global.h"
/* 函数声明 */
PRIVATE void init_idt_desc(unsigned char vector, u8 desc_type, int_handler handler, unsigned char privilege);
PRIVATE void init_descriptor(DESCRIPTOR *p_desc, u32 base, u32 limit, u16 attribute);
/* 中断处理函数 */
void divide_error();
void single_step_exception();
void nmi();
void breakpoint_exception();
void overflow();
void bounds_check();
void inval_opcode();
void copr_not_available();
void double_fault();
void copr_seg_overrun();
void inval_tes();
void segment_not_present();
void stack_exception();
void general_protection();
void page_fault();
void copr_error();
void hwint00();
void hwint01();
void hwint02();
void hwint03();
void hwint04();
void hwint05();
void hwint06();
void hwint07();
void hwint08();
void hwint09();
void hwint10();
void hwint11();
void hwint12();
void hwint13();
void hwint14();
void hwint15();
PUBLIC void init_prot()
{
init_8259A();
// 全部初始化成中断门(没有陷阱门)
init_idt_desc(INT_VECTOR_DIVIDE, DA_386IGate, divide_error, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_DEBUG, DA_386IGate, single_step_exception, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_NMI, DA_386IGate, nmi, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_BREAKPOINT, DA_386IGate, breakpoint_exception, PRIVILEGE_USER);
init_idt_desc(INT_VECTOR_OVERFLOW, DA_386IGate, overflow, PRIVILEGE_USER);
init_idt_desc(INT_VECTOR_BOUNDS, DA_386IGate, bounds_check, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_INVAL_OP, DA_386IGate, inval_opcode, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_COPROC_NOT, DA_386IGate, copr_not_available, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_DOUBLE_FAULT, DA_386IGate, double_fault, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_COPROC_SEG, DA_386IGate, copr_seg_overrun, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_INVAL_TSS, DA_386IGate, inval_tes, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_SEG_NOT, DA_386IGate, segment_not_present, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_STACK_FAULT, DA_386IGate, stack_exception, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_PROTECTION, DA_386IGate, general_protection, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_PAGE_FAULT, DA_386IGate, page_fault, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_COPROC_ERR, DA_386IGate, copr_error, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 0, DA_386IGate, hwint00, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 1, DA_386IGate, hwint01, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 2, DA_386IGate, hwint02, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 3, DA_386IGate, hwint03, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 4, DA_386IGate, hwint04, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 5, DA_386IGate, hwint05, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 6, DA_386IGate, hwint06, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 7, DA_386IGate, hwint07, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 0, DA_386IGate, hwint08, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 1, DA_386IGate, hwint09, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 2, DA_386IGate, hwint10, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 3, DA_386IGate, hwint11, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 4, DA_386IGate, hwint12, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 5, DA_386IGate, hwint13, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 6, DA_386IGate, hwint14, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 7, DA_386IGate, hwint15, PRIVILEGE_KRNL);
/* 填充 GDT 中 TSS 这个描述符 */
memset(&tss, 0, sizeof(tss));
tss.ss0 = SELECTOR_KERNEL_DS;
init_descriptor(&gdt[INDEX_TSS],
vir2phys(seg2phys(SELECTOR_KERNEL_DS), &tss),
sizeof(tss) - 1,
DA_386TSS);
tss.iobase = sizeof(tss); /* 没有I/O许可位图 */
/* 填充 GDT 中进程的 LDT 的描述符 */
init_descriptor(&gdt[INDEX_LDT_FIRST],
vir2phys(seg2phys(SELECTOR_KERNEL_DS), proc_table[0].ldts),
LDT_SIZE * sizeof(DESCRIPTOR) - 1,
DA_LDT);
}
/* 初始化 386 中断门 */
PRIVATE void init_idt_desc(unsigned char vector, u8 desc_type, int_handler handler, unsigned char privilege)
{
GATE* p_gate = &idt[vector];
u32 base = (u32)handler;
p_gate->offset_low = base & 0xFFFF;
p_gate->selector = SELECTOR_KERNEL_CS;
p_gate->dcount = 0;
p_gate->attr = desc_type | (privilege << 5);
p_gate->offset_high = (base >> 16) & 0xFFFF;
}
PRIVATE void init_descriptor(DESCRIPTOR *p_desc, u32 base, u32 limit, u16 attribute)
{
p_desc->limit_low = limit & 0x0FFFF;
p_desc->base_low = base & 0x0FFFF;
p_desc->base_mid = (base >> 16) & 0x0FF;
p_desc->attr1 = attribute & 0xFF;
p_desc->limit_high_attr2 = ((limit>>16) & 0x0F) | (attribute>>8) & 0xF0;
p_desc->base_high = (base >> 24) & 0x0FF;
}
/* 由段名求绝对地址 */
PUBLIC u32 seg2phys(u16 seg)
{
DESCRIPTOR *p_dest = &gdt[seg >> 3];
return (p_dest->base_high<<24 | p_dest->base_mid<<16 | p_dest->base_low);
}
/* 异常处理 */
PUBLIC void exception_handler(int vec_no, int err_code, int eip, int cs, int eflags)
{
int i;
int text_color = 0x74; /* 灰底红字 */
char* err_msg[] = {
"#DE Divide Error",
"#DB RESERVED",
"#-- NMI Interrupt",
"#BP Breakpoint",
"#OF Overflow",
"#BP BOUND Range Exceeded",
"#UD Invalid Opcode (Undefined Opcode)",
"#NM Device Not Available (No Math Coprocessor)",
"#DF Double Fault",
" Coprocessor Segment Overrun (reserved)",
"#TS Invalid TSS",
"#NP Segment Not Present",
"#SS Stack-Segment Fault",
"#GP General Protection",
"#PF Page Fault",
"-- (Intel reserved. Do not use.)",
"#MF x87 FPU Floating-Point Error (Math Fault)",
"#AC Alignment Check",
"#MC Machine Check",
"#XF SIMD Floating-Point Exception"
};
/* 通过打印空格的方式清空屏幕的前五行,并把 disp_pos 清零 */
disp_pos = 0;
for (i = 0; i < 80*5; i++) {
disp_str(" ");
}
disp_pos = 0;
disp_color_str("Exception! --> ", text_color);
disp_color_str(err_msg[vec_no], text_color);
disp_color_str("\n\n", text_color);
disp_color_str("DFLAGS:", text_color);
disp_int(eflags);
disp_color_str("CS:", text_color);
disp_int(cs);
disp_color_str("EIP:", text_color);
disp_int(eip);
if (err_code != 0xFFFFFFFF) {
disp_color_str("Error code:", text_color);
disp_int(err_code);
}
}