程式碼
include/proc.h
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
proc.h
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
typedef struct s_stackframe { /* proc_ptr points here ↑ Low */
u32 gs; /* ┓ │ */
u32 fs; /* ┃ │ */
u32 es; /* ┃ │ */
u32 ds; /* ┃ │ */
u32 edi; /* ┃ │ */
u32 esi; /* ┣ pushed by save() │ */
u32 ebp; /* ┃ │ */
u32 kernel_esp; /* <- 'popad' will ignore it │ */
u32 ebx; /* ┃ ↑棧從高地址往低地址增長*/
u32 edx; /* ┃ │ */
u32 ecx; /* ┃ │ */
u32 eax; /* ┛ │ */
u32 retaddr; /* return address for assembly code save() │ */
u32 eip; /* ┓ │ */
u32 cs; /* ┃ │ */
u32 eflags; /* ┣ these are pushed by CPU during interrupt │ */
u32 esp; /* ┃ │ */
u32 ss; /* ┛ ┷High */
}STACK_FRAME;
typedef struct s_proc {
STACK_FRAME regs; /* process registers saved in stack frame */
u16 ldt_sel; /* gdt selector giving ldt base and limit */
DESCRIPTOR ldts[LDT_SIZE]; /* local descriptors for code and data */
int ticks; /* remained ticks */
int priority;
u32 pid; /* process id passed in from MM */
char p_name[16]; /* name of the process */
}PROCESS;
typedef struct s_task {
task_f initial_eip;
int stacksize;
char name[32];
}TASK;
/* Number of tasks */
#define NR_TASKS 3
/* stacks of tasks */
#define STACK_SIZE_TESTA 0x8000
#define STACK_SIZE_TESTB 0x8000
#define STACK_SIZE_TESTC 0x8000
#define STACK_SIZE_TOTAL (STACK_SIZE_TESTA + \
STACK_SIZE_TESTB + \
STACK_SIZE_TESTC)
include/protect.h
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
protect.h
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#ifndef _ORANGES_PROTECT_H_
#define _ORANGES_PROTECT_H_
/* 存儲段描述符/系統段描述符 */
typedef struct s_descriptor /* 共 8 個字節 */
{
u16 limit_low; /* Limit */
u16 base_low; /* Base */
u8 base_mid; /* Base */
u8 attr1; /* P(1) DPL(2) DT(1) TYPE(4) */
u8 limit_high_attr2; /* G(1) D(1) 0(1) AVL(1) LimitHigh(4) */
u8 base_high; /* Base */
}DESCRIPTOR;
/* 門描述符 */
typedef struct s_gate
{
u16 offset_low; /* Offset Low */
u16 selector; /* Selector */
u8 dcount; /* 該字段只在調用門描述符中有效。
如果在利用調用門調用子程序時引起特權級的轉換和堆棧的改變，需要將外層堆棧中的參數複製到內層堆棧。
該雙字計數字段就是用於說明這種情況發生時，要複製的雙字參數的數量。 */
u8 attr; /* P(1) DPL(2) DT(1) TYPE(4) */
u16 offset_high; /* Offset High */
}GATE;
typedef struct s_tss {
u32 backlink;
u32 esp0; /* stack pointer to use during interrupt */
u32 ss0; /* " segment " " " " */
u32 esp1;
u32 ss1;
u32 esp2;
u32 ss2;
u32 cr3;
u32 eip;
u32 flags;
u32 eax;
u32 ecx;
u32 edx;
u32 ebx;
u32 esp;
u32 ebp;
u32 esi;
u32 edi;
u32 es;
u32 cs;
u32 ss;
u32 ds;
u32 fs;
u32 gs;
u32 ldt;
u16 trap;
u16 iobase; /* I/O位圖基址大於或等於TSS段界限，就表示沒有I/O許可位圖 */
/*u8 iomap[2];*/
}TSS;
/* GDT */
/* 描述符索引 */
#define INDEX_DUMMY 0 // ┓
#define INDEX_FLAT_C 1 // ┣ LOADER 裡面已經確定了的.
#define INDEX_FLAT_RW 2 // ┃
#define INDEX_VIDEO 3 // ┛
#define INDEX_TSS 4
#define INDEX_LDT_FIRST 5
/* 選擇子 */
#define SELECTOR_DUMMY 0 // ┓
#define SELECTOR_FLAT_C 0x08 // ┣ LOADER 裡面已經確定了的.
#define SELECTOR_FLAT_RW 0x10 // ┃
#define SELECTOR_VIDEO (0x18+3) // ┛<-- RPL=3
#define SELECTOR_TSS 0x20 // TSS. 從外層跳到內存時 SS 和 ESP 的值從裡面獲得.
#define SELECTOR_LDT_FIRST 0x28
#define SELECTOR_KERNEL_CS SELECTOR_FLAT_C
#define SELECTOR_KERNEL_DS SELECTOR_FLAT_RW
#define SELECTOR_KERNEL_GS SELECTOR_VIDEO
/* 每個任務有一個單獨的 LDT, 每個 LDT 中的描述符個數: */
#define LDT_SIZE 2
/* 描述符類型值說明 */
#define DA_32 0x4000 /* 32 位段 */
#define DA_LIMIT_4K 0x8000 /* 段界限粒度為 4K 字節 */
#define DA_DPL0 0x00 /* DPL = 0 */
#define DA_DPL1 0x20 /* DPL = 1 */
#define DA_DPL2 0x40 /* DPL = 2 */
#define DA_DPL3 0x60 /* DPL = 3 */
/* 存儲段描述符類型值說明 */
#define DA_DR 0x90 /* 存在的只讀數據段類型值 */
#define DA_DRW 0x92 /* 存在的可讀寫數據段屬性值 */
#define DA_DRWA 0x93 /* 存在的已訪問可讀寫數據段類型值 */
#define DA_C 0x98 /* 存在的只執行代碼段屬性值 */
#define DA_CR 0x9A /* 存在的可執行可讀代碼段屬性值 */
#define DA_CCO 0x9C /* 存在的只執行一致代碼段屬性值 */
#define DA_CCOR 0x9E /* 存在的可執行可讀一致代碼段屬性值 */
/* 系統段描述符類型值說明 */
#define DA_LDT 0x82 /* 局部描述符表段類型值 */
#define DA_TaskGate 0x85 /* 任務門類型值 */
#define DA_386TSS 0x89 /* 可用 386 任務狀態段類型值 */
#define DA_386CGate 0x8C /* 386 調用門類型值 */
#define DA_386IGate 0x8E /* 386 中斷門類型值 */
#define DA_386TGate 0x8F /* 386 陷阱門類型值 */
/* 選擇子類型值說明 */
/* 其中, SA_ : Selector Attribute */
#define SA_RPL_MASK 0xFFFC
#define SA_RPL0 0
#define SA_RPL1 1
#define SA_RPL2 2
#define SA_RPL3 3
#define SA_TI_MASK 0xFFFB
#define SA_TIG 0
#define SA_TIL 4
/* 中斷向量 */
#define INT_VECTOR_DIVIDE 0x0
#define INT_VECTOR_DEBUG 0x1
#define INT_VECTOR_NMI 0x2
#define INT_VECTOR_BREAKPOINT 0x3
#define INT_VECTOR_OVERFLOW 0x4
#define INT_VECTOR_BOUNDS 0x5
#define INT_VECTOR_INVAL_OP 0x6
#define INT_VECTOR_COPROC_NOT 0x7
#define INT_VECTOR_DOUBLE_FAULT 0x8
#define INT_VECTOR_COPROC_SEG 0x9
#define INT_VECTOR_INVAL_TSS 0xA
#define INT_VECTOR_SEG_NOT 0xB
#define INT_VECTOR_STACK_FAULT 0xC
#define INT_VECTOR_PROTECTION 0xD
#define INT_VECTOR_PAGE_FAULT 0xE
#define INT_VECTOR_COPROC_ERR 0x10
/* 中斷向量 */
#define INT_VECTOR_IRQ0 0x20
#define INT_VECTOR_IRQ8 0x28
/* 系統調用 */
#define INT_VECTOR_SYS_CALL 0x90
/* 宏 */
/* 線性地址 → 物理地址 */
#define vir2phys(seg_base, vir) (u32)(((u32)seg_base) + (u32)(vir))
#endif /* _ORANGES_PROTECT_H_ */
include/proto.h
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
proto.h
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
/* klib.asm */
PUBLIC void out_byte(u16 port, u8 value);
PUBLIC u8 in_byte(u16 port);
PUBLIC void disp_str(char * info);
PUBLIC void disp_color_str(char * info, int color);
/* protect.c */
PUBLIC void init_prot();
PUBLIC u32 seg2phys(u16 seg);
/* klib.c */
PUBLIC void delay(int time);
/* kernel.asm */
void restart();
/* main.c */
void TestA();
void TestB();
void TestC();
/* i8259.c */
PUBLIC void put_irq_handler(int irq, irq_handler handler);
PUBLIC void spurious_irq(int irq);
/* clock.c */
PUBLIC void clock_handler(int irq);
/* 以下是系統調用相關 */
/* proc.c */
PUBLIC int sys_get_ticks(); /* sys_call */
/* syscall.asm */
PUBLIC void sys_call(); /* int_handler */
PUBLIC int get_ticks();
include/type.h
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
type.h
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#ifndef _ORANGES_TYPE_H_
#define _ORANGES_TYPE_H_
typedef unsigned int u32;
typedef unsigned short u16;
typedef unsigned char u8;
typedef void (*int_handler) ();
typedef void (*task_f) ();
typedef void (*irq_handler) (int irq);
typedef void* system_call;
#endif /* _ORANGES_TYPE_H_ */
kernel/clock.c
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
clock.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "string.h"
#include "proc.h"
#include "global.h"
/*======================================================================*
clock_handler
*======================================================================*/
PUBLIC void clock_handler(int irq)
{
ticks++;
p_proc_ready->ticks--;
if (k_reenter != 0) {
return;
}
if (p_proc_ready->ticks > 0) {
return;
}
schedule();
}
/*======================================================================*
milli_delay
*======================================================================*/
PUBLIC void milli_delay(int milli_sec)
{
int t = get_ticks();
while(((get_ticks() - t) * 1000 / HZ) < milli_sec) {}
}
kernel/global.c
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
global.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#define GLOBAL_VARIABLES_HERE
#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "proc.h"
#include "global.h"
PUBLIC PROCESS proc_table[NR_TASKS];
PUBLIC char task_stack[STACK_SIZE_TOTAL];
PUBLIC TASK task_table[NR_TASKS] = {{TestA, STACK_SIZE_TESTA, "TestA"},
{TestB, STACK_SIZE_TESTB, "TestB"},
{TestC, STACK_SIZE_TESTC, "TestC"}};
PUBLIC irq_handler irq_table[NR_IRQ];
PUBLIC system_call sys_call_table[NR_SYS_CALL] = {sys_get_ticks};
kernel/i8259.c
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
i8259.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "proc.h"
#include "global.h"
/*======================================================================*
init_8259A
*======================================================================*/
PUBLIC void init_8259A()
{
out_byte(INT_M_CTL, 0x11); // Master 8259, ICW1.
out_byte(INT_S_CTL, 0x11); // Slave 8259, ICW1.
out_byte(INT_M_CTLMASK, INT_VECTOR_IRQ0); // Master 8259, ICW2. 設置 '主8259' 的中斷入口地址為 0x20.
out_byte(INT_S_CTLMASK, INT_VECTOR_IRQ8); // Slave 8259, ICW2. 設置 '從8259' 的中斷入口地址為 0x28
out_byte(INT_M_CTLMASK, 0x4); // Master 8259, ICW3. IR2 對應 '從8259'.
out_byte(INT_S_CTLMASK, 0x2); // Slave 8259, ICW3. 對應 '主8259' 的 IR2.
out_byte(INT_M_CTLMASK, 0x1); // Master 8259, ICW4.
out_byte(INT_S_CTLMASK, 0x1); // Slave 8259, ICW4.
out_byte(INT_M_CTLMASK, 0xFF); // Master 8259, OCW1.
out_byte(INT_S_CTLMASK, 0xFF); // Slave 8259, OCW1.
int i;
for (i = 0; i < NR_IRQ; i++)
irq_table[i] = spurious_irq;
}
/*======================================================================*
spurious_irq
*======================================================================*/
PUBLIC void spurious_irq(int irq)
{
disp_str("spurious_irq: ");
disp_int(irq);
disp_str("\n");
}
/*======================================================================*
put_irq_handler
*======================================================================*/
PUBLIC void put_irq_handler(int irq, irq_handler handler)
{
disable_irq(irq);
irq_table[irq] = handler;
}
kernel/kernel.asm
; ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; kernel.asm
; ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Forrest Yu, 2005
; ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%include "sconst.inc"
; 導入函數
extern cstart
extern kernel_main
extern exception_handler
extern spurious_irq
extern clock_handler
extern disp_str
extern delay
extern irq_table
; 導入全局變量
extern gdt_ptr
extern idt_ptr
extern p_proc_ready
extern tss
extern disp_pos
extern k_reenter
extern sys_call_table
bits 32
[SECTION .data]
clock_int_msg db "^", 0
[SECTION .bss]
StackSpace resb 2 * 1024
StackTop: ; 堆疊頂
[section .text] ; 程式碼在此
global _start ; 導出 _start
global restart
global sys_call
global divide_error
global single_step_exception
global nmi
global breakpoint_exception
global overflow
global bounds_check
global inval_opcode
global copr_not_available
global double_fault
global copr_seg_overrun
global inval_tss
global segment_not_present
global stack_exception
global general_protection
global page_fault
global copr_error
global hwint00
global hwint01
global hwint02
global hwint03
global hwint04
global hwint05
global hwint06
global hwint07
global hwint08
global hwint09
global hwint10
global hwint11
global hwint12
global hwint13
global hwint14
global hwint15
_start:
; 此時記憶體看上去是這樣的（更詳細的記憶體情況在 LOADER.ASM 中有說明）：
; ┃ ┃
; ┃ ... ┃
; ┣━━━━━━━━━━━━━━━━━━┫
; ┃■■■■■■Page Tables■■■■■■┃
; ┃■■■■■(大小由LOADER決定)■■■■┃ PageTblBase
; 00101000h ┣━━━━━━━━━━━━━━━━━━┫
; ┃■■■■Page Directory Table■■■■┃ PageDirBase = 1M
; 00100000h ┣━━━━━━━━━━━━━━━━━━┫
; ┃□□□□ Hardware Reserved □□□□┃ B8000h ← gs
; 9FC00h ┣━━━━━━━━━━━━━━━━━━┫
; ┃■■■■■■■LOADER.BIN■■■■■■┃ somewhere in LOADER ← esp
; 90000h ┣━━━━━━━━━━━━━━━━━━┫
; ┃■■■■■■■KERNEL.BIN■■■■■■┃
; 80000h ┣━━━━━━━━━━━━━━━━━━┫
; ┃■■■■■■■■KERNEL■■■■■■■┃ 30400h ← KERNEL 入口 (KernelEntryPointPhyAddr)
; 30000h ┣━━━━━━━━━━━━━━━━━━┫
; ┋ ... ┋
; ┋ ┋
; 0h ┗━━━━━━━━━━━━━━━━━━┛ ← cs, ds, es, fs, ss
;
;
; GDT 以及相應的描述符是這樣的：
;
; Descriptors Selectors
; ┏━━━━━━━━━━━━━━━━━━┓
; ┃ Dummy Descriptor ┃
; ┣━━━━━━━━━━━━━━━━━━┫
; ┃ DESC_FLAT_C (0～4G) ┃ 8h = cs
; ┣━━━━━━━━━━━━━━━━━━┫
; ┃ DESC_FLAT_RW (0～4G) ┃ 10h = ds, es, fs, ss
; ┣━━━━━━━━━━━━━━━━━━┫
; ┃ DESC_VIDEO ┃ 1Bh = gs
; ┗━━━━━━━━━━━━━━━━━━┛
;
; 注意! 在使用 C 程式碼的時候一定要保證 ds, es, ss 這幾個段暫存器的值是一樣的
; 因為編譯器有可能編譯出使用它們的程式碼, 而編譯器默認它們是一樣的. 比如串拷貝操作會用到 ds 和 es.
;
;
; 把 esp 從 LOADER 挪到 KERNEL
mov esp, StackTop ; 堆疊在 bss 段中
mov dword [disp_pos], 0
sgdt [gdt_ptr] ; cstart() 中將會用到 gdt_ptr
call cstart ; 在此函數中改變了gdt_ptr，讓它指向新的GDT
lgdt [gdt_ptr] ; 使用新的GDT
lidt [idt_ptr]
jmp SELECTOR_KERNEL_CS:csinit
csinit: ; “這個跳轉指令強制使用剛剛初始化的結構”——<<OS:D&I 2nd>> P90.
;jmp 0x40:0
;ud2
xor eax, eax
mov ax, SELECTOR_TSS
ltr ax
;sti
jmp kernel_main
;hlt
; 中斷和異常 -- 硬件中斷
; ---------------------------------
%macro hwint_master 1
call save
in al, INT_M_CTLMASK ; `.
or al, (1 << %1) ; | 屏蔽當前中斷
out INT_M_CTLMASK, al ; /
mov al, EOI ; `. 置EOI位
out INT_M_CTL, al ; /
sti ; CPU在響應中斷的過程中會自動關中斷，這句之後就允許響應新的中斷
push %1 ; `.
call [irq_table + 4 * %1] ; | 中斷處理程序
pop ecx ; /
cli
in al, INT_M_CTLMASK ; `.
and al, ~(1 << %1) ; | 恢復接受當前中斷
out INT_M_CTLMASK, al ; /
ret
%endmacro
ALIGN 16
hwint00: ; Interrupt routine for irq 0 (the clock).
hwint_master 0
ALIGN 16
hwint01: ; Interrupt routine for irq 1 (keyboard)
hwint_master 1
ALIGN 16
hwint02: ; Interrupt routine for irq 2 (cascade!)
hwint_master 2
ALIGN 16
hwint03: ; Interrupt routine for irq 3 (second serial)
hwint_master 3
ALIGN 16
hwint04: ; Interrupt routine for irq 4 (first serial)
hwint_master 4
ALIGN 16
hwint05: ; Interrupt routine for irq 5 (XT winchester)
hwint_master 5
ALIGN 16
hwint06: ; Interrupt routine for irq 6 (floppy)
hwint_master 6
ALIGN 16
hwint07: ; Interrupt routine for irq 7 (printer)
hwint_master 7
; ---------------------------------
%macro hwint_slave 1
push %1
call spurious_irq
add esp, 4
hlt
%endmacro
; ---------------------------------
ALIGN 16
hwint08: ; Interrupt routine for irq 8 (realtime clock).
hwint_slave 8
ALIGN 16
hwint09: ; Interrupt routine for irq 9 (irq 2 redirected)
hwint_slave 9
ALIGN 16
hwint10: ; Interrupt routine for irq 10
hwint_slave 10
ALIGN 16
hwint11: ; Interrupt routine for irq 11
hwint_slave 11
ALIGN 16
hwint12: ; Interrupt routine for irq 12
hwint_slave 12
ALIGN 16
hwint13: ; Interrupt routine for irq 13 (FPU exception)
hwint_slave 13
ALIGN 16
hwint14: ; Interrupt routine for irq 14 (AT winchester)
hwint_slave 14
ALIGN 16
hwint15: ; Interrupt routine for irq 15
hwint_slave 15
; 中斷和異常 -- 異常
divide_error:
push 0xFFFFFFFF ; no err code
push 0 ; vector_no = 0
jmp exception
single_step_exception:
push 0xFFFFFFFF ; no err code
push 1 ; vector_no = 1
jmp exception
nmi:
push 0xFFFFFFFF ; no err code
push 2 ; vector_no = 2
jmp exception
breakpoint_exception:
push 0xFFFFFFFF ; no err code
push 3 ; vector_no = 3
jmp exception
overflow:
push 0xFFFFFFFF ; no err code
push 4 ; vector_no = 4
jmp exception
bounds_check:
push 0xFFFFFFFF ; no err code
push 5 ; vector_no = 5
jmp exception
inval_opcode:
push 0xFFFFFFFF ; no err code
push 6 ; vector_no = 6
jmp exception
copr_not_available:
push 0xFFFFFFFF ; no err code
push 7 ; vector_no = 7
jmp exception
double_fault:
push 8 ; vector_no = 8
jmp exception
copr_seg_overrun:
push 0xFFFFFFFF ; no err code
push 9 ; vector_no = 9
jmp exception
inval_tss:
push 10 ; vector_no = A
jmp exception
segment_not_present:
push 11 ; vector_no = B
jmp exception
stack_exception:
push 12 ; vector_no = C
jmp exception
general_protection:
push 13 ; vector_no = D
jmp exception
page_fault:
push 14 ; vector_no = E
jmp exception
copr_error:
push 0xFFFFFFFF ; no err code
push 16 ; vector_no = 10h
jmp exception
exception:
call exception_handler
add esp, 4*2 ; 讓堆疊頂指向 EIP，堆疊中從頂向下依次是：EIP、CS、EFLAGS
hlt
; ====================================================================================
; save
; ====================================================================================
save:
pushad ; `.
push ds ; |
push es ; | 保存原暫存器值
push fs ; |
push gs ; /
mov dx, ss
mov ds, dx
mov es, dx
mov esi, esp ;esi = 進程表起始位址
inc dword [k_reenter] ;k_reenter++;
cmp dword [k_reenter], 0 ;if(k_reenter ==0)
jne .1 ;{
mov esp, StackTop ; mov esp, StackTop <--切換到內核堆疊
push restart ; push restart
jmp [esi + RETADR - P_STACKBASE]; return;
.1: ;} else { 已經在內核堆疊，不需要再切換
push restart_reenter ; push restart_reenter
jmp [esi + RETADR - P_STACKBASE]; return;
;}
; ====================================================================================
; sys_call
; ====================================================================================
sys_call:
call save
sti
call [sys_call_table + eax * 4]
mov [esi + EAXREG - P_STACKBASE], eax
cli
ret
; ====================================================================================
; restart
; ====================================================================================
restart:
mov esp, [p_proc_ready]
lldt [esp + P_LDT_SEL]
lea eax, [esp + P_STACKTOP]
mov dword [tss + TSS3_S_SP0], eax
restart_reenter:
dec dword [k_reenter]
pop gs
pop fs
pop es
pop ds
popad
add esp, 4
iretd
kernel/main.c
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
main.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "string.h"
#include "proc.h"
#include "global.h"
/*======================================================================*
kernel_main
*======================================================================*/
PUBLIC int kernel_main()
{
disp_str("-----\"kernel_main\" begins-----\n");
TASK* p_task = task_table;
PROCESS* p_proc = proc_table;
char* p_task_stack = task_stack + STACK_SIZE_TOTAL;
u16 selector_ldt = SELECTOR_LDT_FIRST;
int i;
for (i = 0; i < NR_TASKS; i++) {
strcpy(p_proc->p_name, p_task->name); // name of the process
p_proc->pid = i; // pid
p_proc->ldt_sel = selector_ldt;
memcpy(&p_proc->ldts[0], &gdt[SELECTOR_KERNEL_CS >> 3],
sizeof(DESCRIPTOR));
p_proc->ldts[0].attr1 = DA_C | PRIVILEGE_TASK << 5;
memcpy(&p_proc->ldts[1], &gdt[SELECTOR_KERNEL_DS >> 3],
sizeof(DESCRIPTOR));
p_proc->ldts[1].attr1 = DA_DRW | PRIVILEGE_TASK << 5;
p_proc->regs.cs = ((8 * 0) & SA_RPL_MASK & SA_TI_MASK)
| SA_TIL | RPL_TASK;
p_proc->regs.ds = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK)
| SA_TIL | RPL_TASK;
p_proc->regs.es = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK)
| SA_TIL | RPL_TASK;
p_proc->regs.fs = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK)
| SA_TIL | RPL_TASK;
p_proc->regs.ss = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK)
| SA_TIL | RPL_TASK;
p_proc->regs.gs = (SELECTOR_KERNEL_GS & SA_RPL_MASK)
| RPL_TASK;
p_proc->regs.eip = (u32)p_task->initial_eip;
p_proc->regs.esp = (u32)p_task_stack;
p_proc->regs.eflags = 0x1202; /* IF=1, IOPL=1 */
p_task_stack -= p_task->stacksize;
p_proc++;
p_task++;
selector_ldt += 1 << 3;
}
proc_table[0].ticks = proc_table[0].priority = 15;
proc_table[1].ticks = proc_table[1].priority = 5;
proc_table[2].ticks = proc_table[2].priority = 3;
k_reenter = 0;
ticks = 0;
p_proc_ready = proc_table;
/* 初始化 8253 PIT */
out_byte(TIMER_MODE, RATE_GENERATOR);
out_byte(TIMER0, (u8) (TIMER_FREQ/HZ) );
out_byte(TIMER0, (u8) ((TIMER_FREQ/HZ) >> 8));
put_irq_handler(CLOCK_IRQ, clock_handler); /* 設定時鐘中斷處理程序 */
enable_irq(CLOCK_IRQ); /* 讓8259A可以接收時鐘中斷 */
restart();
while(1){}
}
/*======================================================================*
TestA
*======================================================================*/
void TestA()
{
int i = 0;
while (1) {
disp_str("A.");
milli_delay(10);
}
}
/*======================================================================*
TestB
*======================================================================*/
void TestB()
{
int i = 0x1000;
while(1){
disp_str("B.");
milli_delay(10);
}
}
/*======================================================================*
TestB
*======================================================================*/
void TestC()
{
int i = 0x2000;
while(1){
disp_str("C.");
milli_delay(10);
}
}
kernel/protect.c
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
protect.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "proc.h"
#include "global.h"
/* 本文件內函數聲明 */
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);
/* 中斷處理函數 */
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_tss();
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();
/*======================================================================*
init_prot
*----------------------------------------------------------------------*
初始化 IDT
*======================================================================*/
PUBLIC void init_prot()
{
init_8259A();
// 全部初始化成中斷門(沒有陷阱門)
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_tss, 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);
init_idt_desc(INT_VECTOR_SYS_CALL, DA_386IGate,
sys_call, PRIVILEGE_USER);
/* 填充 GDT 中 TSS 這個描述符 */
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); /* 沒有I/O許可位圖 */
// 填充 GDT 中進程的 LDT 的描述符
int i;
PROCESS* p_proc = proc_table;
u16 selector_ldt = INDEX_LDT_FIRST << 3;
for(i=0;i<NR_TASKS;i++){
init_descriptor(&gdt[selector_ldt>>3],
vir2phys(seg2phys(SELECTOR_KERNEL_DS),
proc_table[i].ldts),
LDT_SIZE * sizeof(DESCRIPTOR) - 1,
DA_LDT);
p_proc++;
selector_ldt += 1 << 3;
}
}
/*======================================================================*
init_idt_desc
*----------------------------------------------------------------------*
初始化 386 中斷門
*======================================================================*/
PUBLIC 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;
}
/*======================================================================*
seg2phys
*----------------------------------------------------------------------*
由段名求絕對地址
*======================================================================*/
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);
}
/*======================================================================*
init_descriptor
*----------------------------------------------------------------------*
初始化段描述符
*======================================================================*/
PRIVATE void init_descriptor(DESCRIPTOR * p_desc, u32 base, u32 limit, u16 attribute)
{
p_desc->limit_low = limit & 0x0FFFF; // 段界限 1 (2 字節)
p_desc->base_low = base & 0x0FFFF; // 段基址 1 (2 字節)
p_desc->base_mid = (base >> 16) & 0x0FF; // 段基址 2 (1 字節)
p_desc->attr1 = attribute & 0xFF; // 屬性 1
p_desc->limit_high_attr2 = ((limit >> 16) & 0x0F) |
(attribute >> 8) & 0xF0;// 段界限 2 + 屬性 2
p_desc->base_high = (base >> 24) & 0x0FF; // 段基址 3 (1 字節)
}
/*======================================================================*
exception_handler
*----------------------------------------------------------------------*
異常處理
*======================================================================*/
PUBLIC void exception_handler(int vec_no, int err_code, int eip, int cs, int eflags)
{
int i;
int text_color = 0x74; /* 灰底紅字 */
char err_description[][64] = { "#DE Divide Error",
"#DB RESERVED",
"— NMI Interrupt",
"#BP Breakpoint",
"#OF Overflow",
"#BR 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"
};
/* 通過打印空格的方式清空屏幕的前五行，並把 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_description[vec_no], text_color);
disp_color_str("\n\n", text_color);
disp_color_str("EFLAGS:", 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);
}
}
Makefile
#########################
# Makefile for Orange'S #
#########################
# Entry point of Orange'S
# It must have the same value with 'KernelEntryPointPhyAddr' in load.inc!
ENTRYPOINT = 0x30400
# Offset of entry point in kernel file
# It depends on ENTRYPOINT
ENTRYOFFSET = 0x400
# Programs, flags, etc.
ASM = nasm
DASM = ndisasm
CC = gcc
LD = ld
ASMBFLAGS = -I boot/include/
ASMKFLAGS = -I include/ -f elf
CFLAGS = -I include/ -m32 -c -fno-builtin -fno-stack-protector
LDFLAGS = -s -melf_i386 -Ttext $(ENTRYPOINT)
DASMFLAGS = -u -o $(ENTRYPOINT) -e $(ENTRYOFFSET)
# This Program
ORANGESBOOT = boot/boot.bin boot/loader.bin
ORANGESKERNEL = kernel.bin
OBJS = kernel/kernel.o kernel/syscall.o kernel/start.o kernel/main.o kernel/clock.o\
kernel/i8259.o kernel/global.o kernel/protect.o kernel/proc.o\
lib/kliba.o lib/klib.o lib/string.o
DASMOUTPUT = kernel.bin.asm
# All Phony Targets
.PHONY : everything final image clean realclean disasm all buildimg
# Default starting position
nop :
@echo "why not \`make image' huh? :)"
everything : $(ORANGESBOOT) $(ORANGESKERNEL)
all : realclean everything
image : realclean everything clean buildimg
clean :
rm -f $(OBJS)
realclean :
rm -f $(OBJS) $(ORANGESBOOT) $(ORANGESKERNEL)
disasm :
$(DASM) $(DASMFLAGS) $(ORANGESKERNEL) > $(DASMOUTPUT)
# We assume that "a.img" exists in current folder
buildimg :
mkdir tmp
sleep 1
sudo mount -o loop a.img tmp
sleep 1
sudo cp -fv boot/loader.bin tmp
sudo cp -fv kernel.bin tmp
sleep 1
sudo umount tmp
sleep 1
rmdir tmp
boot/boot.bin : boot/boot.asm boot/include/load.inc boot/include/fat12hdr.inc
$(ASM) $(ASMBFLAGS) -o $@ $<
boot/loader.bin : boot/loader.asm boot/include/load.inc boot/include/fat12hdr.inc boot/include/pm.inc
$(ASM) $(ASMBFLAGS) -o $@ $<
$(ORANGESKERNEL) : $(OBJS)
$(LD) $(LDFLAGS) -o $(ORANGESKERNEL) $(OBJS)
kernel/kernel.o : kernel/kernel.asm include/sconst.inc
$(ASM) $(ASMKFLAGS) -o $@ $<
kernel/syscall.o : kernel/syscall.asm include/sconst.inc
$(ASM) $(ASMKFLAGS) -o $@ $<
kernel/start.o: kernel/start.c include/type.h include/const.h include/protect.h include/string.h include/proc.h include/proto.h \
include/global.h
$(CC) $(CFLAGS) -o $@ $<
kernel/main.o: kernel/main.c include/type.h include/const.h include/protect.h include/string.h include/proc.h include/proto.h \
include/global.h
$(CC) $(CFLAGS) -o $@ $<
kernel/clock.o: kernel/clock.c
$(CC) $(CFLAGS) -o $@ $<
kernel/i8259.o: kernel/i8259.c include/type.h include/const.h include/protect.h include/proto.h
$(CC) $(CFLAGS) -o $@ $<
kernel/global.o: kernel/global.c include/type.h include/const.h include/protect.h include/proc.h \
include/global.h include/proto.h
$(CC) $(CFLAGS) -o $@ $<
kernel/protect.o: kernel/protect.c include/type.h include/const.h include/protect.h include/proc.h include/proto.h \
include/global.h
$(CC) $(CFLAGS) -o $@ $<
kernel/proc.o: kernel/proc.c
$(CC) $(CFLAGS) -o $@ $<
lib/klib.o: lib/klib.c include/type.h include/const.h include/protect.h include/string.h include/proc.h include/proto.h \
include/global.h
$(CC) $(CFLAGS) -o $@ $<
lib/kliba.o : lib/kliba.asm
$(ASM) $(ASMKFLAGS) -o $@ $<
lib/string.o : lib/string.asm
$(ASM) $(ASMKFLAGS) -o $@ $<
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