add csrc

lab1/csrc/paging.c

@@ -0,0 +1,191 @@
+// # Copyright 2022 hrpccs
+// #
+// # Licensed under the Apache License, Version 2.0 (the "License");
+// # you may not use this file except in compliance with the License.
+// # You may obtain a copy of the License at
+// #
+// #     http://www.apache.org/licenses/LICENSE-2.0
+// #
+// # Unless required by applicable law or agreed to in writing, software
+// # distributed under the License is distributed on an "AS IS" BASIS,
+// # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// # See the License for the specific language governing permissions and
+// # limitations under the License.
+
+#include "mm.h"
+#include "mmio.h"
+
+
+
+#define SCREEN_COLS 80
+#define SCREEN_ROWS 30
+#define INT_TIMER_LIMIT 50000000
+#define PAGEDIR_BASE 0x5000
+
+typedef unsigned int uint32;
+typedef uint32 pte_t;
+typedef uint32* pagetable_t;
+
+extern void enable_paging();
+extern void enable_interrupt();
+extern int get_mtval();
+
+int wk_mul(int a, int b) {
+  int r = 0;
+  for (; b; a <<= 1, b >>= 1)
+    if (b & 1)
+      r += a;
+  return r;
+}
+
+void memoryset(unsigned char *dest,unsigned char num, unsigned int size){
+    for(unsigned int i=0;i<size;i++){
+        dest[i]=num;
+    }
+}
+
+uint32 pm[8]; //板子上有32kb内存，八个页
+uint32 timercount=0;
+void (*putch_at)(int,int,unsigned char);
+
+void __putch_at(int x, int y, unsigned char ch) {
+	VRAM[wk_mul(y,SCREEN_COLS) + x] = ch;
+}
+
+void __vputch_at(int x, int y, unsigned char ch) {
+	VA_VRAM[wk_mul(y,SCREEN_COLS) + x] = ch;
+}
+
+int alloc(){
+    int index = 0;
+    int max = 8;
+    while(index < max){
+        if(pm[index] == 0){
+            pm[index] = 1;
+            break;
+        }
+        index++;
+    }
+    return index == max ? -1 : index;
+}
+
+void map(pagetable_t pgtbl,uint32 va,uint32 pa,int perm){
+    int t;
+    if((pgtbl[PX(1,va)] & PTE_V )!= PTE_V){ //前缀不存在
+        t=alloc(); //申请一个页给前缀页表
+        if(t>=0){
+            int* taddr = (int*)(t<<12);
+            for(int i=0;i<PGSIZE>>2;i++){
+                taddr[i]=0;
+            }
+            pgtbl[PX(1,va)] = PA2PTE(t<<12) | PTE_V;
+        }else{
+            while(1);
+            for(int i=0;i<14;i++){
+                putch_at(i,22,"out of memory!"[i]);
+            }
+            while(1);
+        }
+    }
+    pagetable_t n = (void*)PTE2PA(pgtbl[PX(1,va)]);
+    n[PX(0,va)] = PA2PTE(pa) | perm | PTE_V;
+}
+
+
+void kvminit(){
+    pagetable_t pgtbl = (void*)PAGEDIR_BASE;
+    // memoryset(pgtbl,0,PGSIZE); //后面需要读这个内存，所以先初始化
+    for(int i=0;i<PGSIZE>>2;i++){
+        pgtbl[i]=0;
+    }
+
+    pm[PAGEDIR_BASE >> 12] = 1;
+    pm[0]=1;
+    pm[1]=1;
+    pm[2]=1;
+    pm[3]=1;
+    pm[4]=1;
+    //create pte mmap for text
+    pgtbl[1023] =  PA2PTE(PAGEDIR_BASE) | PTE_R | PTE_W;
+    map(pgtbl,PAGEDIR_BASE,PAGEDIR_BASE,PTE_R | PTE_W);
+    map(pgtbl,0x0,0x0, PTE_W | PTE_R ); //kernel stack
+    map(pgtbl,0x1000,0x1000, PTE_W | PTE_R | PTE_X ); //
+    map(pgtbl,0x2000,0x2000, PTE_W | PTE_R | PTE_X ); //
+    map(pgtbl,0x3000,0x3000, PTE_W | PTE_R | PTE_X ); //
+    map(pgtbl,0x4000,0x4000, PTE_W | PTE_R | PTE_X ); //
+    map(pgtbl,VA_VRAM_BASE,VRAM_BASE, PTE_W | PTE_R ); //
+    map(pgtbl,VA_VRAM_BASE + PGSIZE,VRAM_BASE + PGSIZE, PTE_W | PTE_R);
+    map(pgtbl,VA_UART_BASE,UART_BASE, PTE_W | PTE_R ); //
+    map(pgtbl,VA_TIMER_BASE,TIMER_BASE, PTE_W | PTE_R ); //
+}
+
+void clear_screen() {
+	int *vram = ((int *) VRAM_BASE);
+	for (int i = 0; i < 600; ++i) vram[i] = 0x20202020;
+}
+
+void trap_handler(void *epc, unsigned int cause) {
+	if (cause == 10 || cause == 15 || cause == 13) {
+        for(int i=0;i<39;i++){
+            putch_at(i,4,"A not handled page fault caused by : 0x"[i]);
+        }
+        int mtval = get_mtval();
+        char ch;
+        for (int i = 0; i < 8; ++i) {
+            unsigned int mask = 0xF << (i * 4);
+            unsigned int num = (mtval & mask) >> (i * 4);
+            if(num >= 10){
+                ch = num - 10 + 'A';
+            }else{
+                ch = num + '0';
+            }
+		    putch_at(39+7-i,4,ch);
+	    }
+        while(1); //目前还没有处理page-fault，因为还没有建立完整的映射。
+	} else if(cause == 0x80000007){
+        for(int i=0;i<16;i++){
+            putch_at(i,3,"timer count : 0x"[i]);
+        }
+        char ch;
+        for (int i = 0; i < 8; ++i) {
+            unsigned int mask = 0xF << (i * 4);
+            unsigned int num = (timercount & mask) >> (i * 4);
+            if(num >= 10){
+                ch = num - 10 + 'A';
+            }else{
+                ch = num + '0';
+            }
+		    putch_at(16+7-i,3,ch);
+	    }
+        timercount += 1;
+
+    }
+}
+
+int main(){
+    putch_at = __putch_at;
+    for(int i=0;i<8;i++){
+        pm[i] = 0;
+    }
+    timercount = 0;
+    clear_screen();
+    for(int i=0;i<19;i++){
+        putch_at(i,0,"print before paging"[i]);
+    }
+    kvminit();
+    putch_at = __vputch_at;
+    enable_paging();
+    for(int i=0;i<18;i++){
+        putch_at(i,1,"print after paging"[i]);
+    }
+    enable_interrupt();
+    *VA_TIMER_ENABLED = 1;
+    *VA_TIMER_LIMIT = INT_TIMER_LIMIT;
+
+    while(1){
+        if(timercount == 0x20){
+            *(int*)0x11415 = 1130;
+        }
+    }
+    for(;;);
+}