1. /************************************************ 
2.   NAME      : MMU.C
3.   DESC    :
4.   Revision  : 1.0
5.  ************************************************/  
6.   
7. #include "def.h"  
8. #include "option.h"  
9. #include "2440addr.h"  
10. #include "2440lib.h"  
11. #include "2440slib.h"  
12. #include "mmu.h"  
13.   
14. // 1) Only the section table is used.   
15. // 2) The cachable/non-cachable area can be changed by MMT_DEFAULT value.  
16. //    The section size is 1MB.  
17.   
18.    
19. extern char __ENTRY[];    
20.   
21. void MMU_Init(void)  
22. {  
23.     int i,j;  
24. /*
25.     这段程序不能实现当前堆栈和代码区域的重新映射，假如你
26.     想让存储区域自由映射，需要你自己编写一个细致入微的MMU初始化代码
27.     */  
28. //========================== IMPORTANT NOTE =========================  
29. //The current stack and code area can't be re-mapped in this routine.  
30. //If you want memory map mapped freely, your own sophiscated MMU  
31. //initialization code is needed.  
32. //===================================================================  
33.   
34. //禁止数据高速缓存  
35. //禁止指令高速缓存  
36.   
37. //要使用回写操作，一定要对DCache进行清除  
38. //If write-back is used,the DCache should be cleared.  
39. for(i=0;i<64;i++)  
40. for(j=0;j<8;j++)  
41. //使整个DCache的数据无效  
42. //使无效整个指令Cache  
43.       
44. if 0  
45. //To complete MMU_Init() fast, Icache may be turned on here.  
46. //为了快速完成MMU_Init(), Icache在这打开。  
47.     MMU_EnableICache();   
48. endif  
49.       
50. //禁止MMU  
51. //使快表无效  
52.   
53. //MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr)  
54. //MMU_SetMTT(0x00000000,0x07f00000,0x00000000,RW_CNB);  //bank0  
55. //bank0  
56. //bank0  
57. //bank1  
58. //bank2  
59. //bank3  
60. //MMU_SetMTT(0x20000000,0x27f00000,0x20000000,RW_CB); //bank4  
61. //bank4 for STRATA Flash  
62. //bank5  
63. //30f00000->30100000, 31000000->30200000  
64. //bank6-1  
65. //bank6-2  
66. //  
67. //bank6-3  
68. //bank7  
69.       
70. //SFR  
71. //SFR  
72. //SFR  
73. //not used  
74.   
75.       
76. //写转换表基地址到C2  
77.     MMU_SetDomain(0x55555550|DOMAIN1_ATTR|DOMAIN0_ATTR);   
78. //DOMAIN1: no_access, DOMAIN0,2~15=client(AP is checked)  
79. //写域访问控制位到C3  
80. //快速上下文切换,禁止? MVA="VA"  
81. //是否开启地址对齐检查功能  
82.           
83. //使能MMU  
84. // 使能ICache  
85.   
86. //DCache 必须要打开，当MMU打开时.  
87. //DCache should be turned on after MMU is turned on.  
88. }      
89.   
90.   
91. // attr=RW_CB,RW_CNB,RW_NCNB,RW_FAULT  
92. void ChangeRomCacheStatus(int attr)  
93. {  
94.     int i,j;  
95.     MMU_DisableDCache();  
96.     MMU_DisableICache();  
97. //If write-back is used,the DCache should be cleared.  
98. for(i=0;i<64;i++)  
99. for(j=0;j<8;j++)  
100.             MMU_CleanInvalidateDCacheIndex((i<<26)|(j<<5));  
101.     MMU_InvalidateICache();  
102.     MMU_DisableMMU();  
103.     MMU_InvalidateTLB();  
104. //bank0  
105. //bank1  
106.     MMU_EnableMMU();  
107.     MMU_EnableICache();  
108.     MMU_EnableDCache();  
109. }      
110.       
111.   
112. void MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr)  
113. {  
114. //定义了页表的指针  
115.     volatile int i,nSec;  
116. //由于内存块是1M的，写页表的基地址  
117. // nSec:段大小  
118.   
119. //页表存储访问信息和存储块的基地址  
120. //(((paddrStart>>20)+i)<<20) ：对应的物理内存页的地址  
121. // attr：访问权限和缓冲属性  
122. for(i=0;i<=nSec;i++)*pTT++=attr |(((paddrStart>>20)+i)<<20);  
123. }  
124.   
125. /************************************************ 
126.   NAME    : MMU.H
127.   DESC    :
128.   Revision: 1.0
129.  ************************************************/  
130.   
131. #include "2440slib.h"  
132.   
133. #ifndef __MMU_H__  
134. #define __MMU_H__  
135. #ifdef __cplusplus  
136. extern "C" {  
137. #endif  
138.   
139. #define DESC_SEC    (0x2|(1<<4))  
140. #define CB      (3<<2)  //cache_on, write_back  
141. #define CNB     (2<<2)  //cache_on, write_through   
142. #define NCB             (1<<2)  //cache_off,WR_BUF on  
143. #define NCNB        (0<<2)  //cache_off,WR_BUF off  
144. #define AP_RW       (3<<10) //supervisor=RW, user=RW  
145. #define AP_RO       (2<<10) //supervisor=RW, user=RO  
146.   
147. #define DOMAIN_FAULT    (0x0)  
148. #define DOMAIN_CHK  (0x1)   
149. #define DOMAIN_NOTCHK   (0x3)   
150. #define DOMAIN0     (0x0<<5)  
151. #define DOMAIN1     (0x1<<5)  
152.   
153. #define DOMAIN0_ATTR    (DOMAIN_CHK<<0)   
154. #define DOMAIN1_ATTR    (DOMAIN_FAULT<<2)   
155.   
156. #define RW_CB       (AP_RW|DOMAIN0|CB|DESC_SEC)  
157. #define RW_CNB      (AP_RW|DOMAIN0|CNB|DESC_SEC)  
158. #define RW_NCNB     (AP_RW|DOMAIN0|NCNB|DESC_SEC)  
159. #define RW_FAULT    (AP_RW|DOMAIN1|NCNB|DESC_SEC)  
160.   
161. void MMU_Init(void);  
162. void MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr);  
163. void ChangeRomCacheStatus(int attr);  
164.   
165. #ifdef __cplusplus  
166. }  
167. #endif  
168.   
169. #endif /*__MMU_H__*/  
170.   
171. //具体.h参数请翻看数据手册，及《ARM体系结构与编程+杜春雷》一书  
172.