1 #define LOG2NENV        10
2 #define NENV            (1<<LOG2NENV)
3 #define ENVX(envid)     ((envid) & (NENV - 1))
4 #define GET_ENV_ASID(envid) (((envid)>> 11)<<6)

1 // Values of env_status in struct Env
2 #define ENV_FREE    0
3 #define ENV_RUNNABLE        1
4 #define ENV_NOT_RUNNABLE    2

 1 struct Env {
 2     struct Trapframe env_tf;        // 用来保存上下文寄存器的结构体，在trap.h中定义。
 3     LIST_ENTRY(Env) env_link;       // 空闲链表
 4     u_int env_id;                   // 每个进程独一无二的编号
 5     u_int env_parent_id;            // 父进程的id
 6     u_int env_status;               // 进程控制块的状态
 7     Pde  *env_pgdir;                // 进程对应页目录的内核虚拟地址
 8     u_int env_cr3;                  // 进程对应页目录首地址寄存器的值，cr3寄存器不同的值对应不同地址空间
 9     LIST_ENTRY(Env) env_sched_link; // 进程调度队列中用来链接的域
10     u_int env_pri;                  // 进程优先级，体现在时间片轮转法中是进程可以连续占有的时间片个数
11     
12     // Lab 4 IPC
13     u_int env_ipc_value;            // 进程间通信发送的内容
14     u_int env_ipc_from;             // 信息发送者进程的id  
15     u_int env_ipc_recving;          // 进程是否处于接收信息的状态
16     u_int env_ipc_dstva;            // 发送信息的虚拟地址（是某一页内存的首地址）
17     u_int env_ipc_perm;                // 发送的内存页进行映射时的权限
18 
19     // Lab 4 fault handling
20     u_int env_pgfault_handler;      // 缺页中断的handler
21     u_int env_xstacktop;            // 异常处理栈的栈顶位置
22 
23     // Lab 6 scheduler counts
24     u_int env_runs;                    // 进程被调度的次数
25     u_int env_nop;                  // align to avoid mul instruction（似乎是为了对齐额外定义的量）
26 };

 1 struct Trapframe { //lr:need to be modified(reference to linux pt_regs) TODO
 2     /* Saved main processor registers. */
 3     unsigned long regs[32];
 4 
 5     /* Saved special registers. */
 6     unsigned long cp0_status;
 7     unsigned long hi;
 8     unsigned long lo;
 9     unsigned long cp0_badvaddr;
10     unsigned long cp0_cause;
11     unsigned long cp0_epc;
12     unsigned long pc;
13 };

 1 // for the grading script
 2 #define ENV_CREATE2(x, y)  3 {  4     extern u_char x[], y[];  5     env_create(x, (int)y);  6 }
 7 #define ENV_CREATE_PRIORITY(x, y)  8 { 9         extern u_char binary_##x##_start[]; 10         extern u_int binary_##x##_size;11         env_create_priority(binary_##x##_start, 12                 (u_int)binary_##x##_size, y);13 }
14 #define ENV_CREATE(x) 15 { 16     extern u_char binary_##x##_start[];17     extern u_int binary_##x##_size; 18     env_create(binary_##x##_start, 19         (u_int)binary_##x##_size); 20 }

|offset|                                                        
|-----------|---BY2PG---|---......----|---BY2PG---|-----------|00000000000|000....000|00000000000|
       ^                                                ^                               
       va                                          va+bin_size

 1 .section .text.exc_vec3
 2 NESTED(except_vec3, 0, sp)
 3         .set    noat
 4         .set    noreorder
 5         /*
 6          * Register saving is delayed as long as we don‘t know
 7          * which registers really need to be saved.
 8          */
 9 1:
10         mfc0    k1,CP0_CAUSE
11         la    k0,exception_handlers
12         /*
13          * Next lines assumes that the used CPU type has max.
14          * 32 different types of exceptions. We might use this
15          * to implement software exceptions in the future.
16          */
17 
18         andi    k1,0x7c
19         addu    k0,k1
20         lw    k0,(k0)
21         NOP
22         jr    k0
23         nop
24         END(except_vec3)
25         .set    at

 1 void trap_init(){
 2     int i;
 3     for(i=0;i<32;i++)
 4     set_except_vector(i, handle_reserved);
 5     set_except_vector(0, handle_int);
 6     set_except_vector(1, handle_mod);
 7     set_except_vector(2, handle_tlb);
 8     set_except_vector(3, handle_tlb);
 9     set_except_vector(8, handle_sys);
10 }
11 void *set_except_vector(int n, void * addr){
12     unsigned long handler=(unsigned long)addr;
13     unsigned long old_handler=exception_handlers[n];
14     exception_handlers[n]=handler;
15     return (void *)old_handler;
16 }

 1 #include <asm/regdef.h>
 2 #include <asm/cp0regdef.h>
 3 #include <asm/asm.h>
 4 #include <kclock.h>
 5 
 6 .macro    setup_c0_status set clr
 7     .set    push
 8     mfc0    t0, CP0_STATUS
 9     or    t0, \set|\clr
10     xor    t0, \clr
11     mtc0    t0, CP0_STATUS            
12     .set    pop
13 .endm
14 
15     .text
16 LEAF(set_timer)
17 
18     li t0, 0x01
19     sb t0, 0xb5000100
20     sw    sp, KERNEL_SP
21 setup_c0_status STATUS_CU0|0x1001 0
22     jr ra
23 
24     nop
25 END(set_timer)