| | 1 | #include <linux/config.h>\r |
| | 2 | #include <linux/module.h>\r |
| | 3 | #include <linux/kernel.h>\r |
| | 4 | #include <linux/init.h>\r |
| | 5 | #include <linux/miscdevice.h>\r |
| | 6 | #include <asm/memory.h>\r |
| | 7 | \r |
| | 8 | #define MMUHACK_MINOR 225\r |
| | 9 | #define DEVICE_NAME "mmuhack"\r |
| | 10 | \r |
| | 11 | #if __GNUC__ == 3\r |
| | 12 | #include <linux/version.h>\r |
| | 13 | static const char __module_kernel_version_gcc3[] __attribute__((__used__)) __attribute__((section(".modinfo"))) =\r |
| | 14 | "kernel_version=" UTS_RELEASE;\r |
| | 15 | #endif\r |
| | 16 | \r |
| | 17 | static ssize_t mmuhack_open(struct inode *inode, struct file *filp)\r |
| | 18 | {\r |
| | 19 | unsigned int *pgtable;\r |
| | 20 | unsigned int *cpt;\r |
| | 21 | int i, j;\r |
| | 22 | int ttb;\r |
| | 23 | int ret = -EFAULT;\r |
| | 24 | \r |
| | 25 | // get the pointer to the translation table base...\r |
| | 26 | asm volatile(\r |
| | 27 | "stmdb sp!, {r0}\n\t"\r |
| | 28 | "mrc p15, 0, r0, c2, c0, 0\n\t"\r |
| | 29 | "mov %0, r0\n\t"\r |
| | 30 | "ldmia sp!, {r0}\n\t": "=r"(ttb)\r |
| | 31 | );\r |
| | 32 | \r |
| | 33 | pgtable = __va(ttb);\r |
| | 34 | \r |
| | 35 | for (i = 0; i < 4096; i ++) if ( (pgtable[i] & 3) == 1 ) {\r |
| | 36 | cpt = __va(pgtable[i] & 0xfffffc00);\r |
| | 37 | \r |
| | 38 | for (j = 0; j < 256; j ++) {/*\r |
| | 39 | if ( (cpt[j] & 0xfe00000f) == 0x02000002 ) {\r |
| | 40 | // set C and B bits in upper 32MB memory area...\r |
| | 41 | printk("Set C&B bits %08x\n",cpt[j]);\r |
| | 42 | cpt[j] |= 0xFFC;\r |
| | 43 | ret = 0;\r |
| | 44 | }\r |
| | 45 | */\r |
| | 46 | if (((cpt[j] & 0xff000000) == 0x02000000) && ((cpt[j] & 12)==0) )\r |
| | 47 | {\r |
| | 48 | //printk("Set C&B bits %08x\n",cpt[j]);\r |
| | 49 | cpt[j] |= 0xFFC;\r |
| | 50 | }\r |
| | 51 | //if ((a>=0x31 && a<=0x36) && ((cpt[i] & 12)==0))\r |
| | 52 | if (((cpt[j] & 0xff000000) == 0x03000000) && ((cpt[j] & 12)==0))\r |
| | 53 | {\r |
| | 54 | //printk("Set C&B bits %08x\n",cpt[j]);\r |
| | 55 | //printf("SDL c and b bits not set, overwriting\n");\r |
| | 56 | cpt[j] |= 0xFFC;\r |
| | 57 | }\r |
| | 58 | }\r |
| | 59 | }\r |
| | 60 | \r |
| | 61 | // drain the write buffer and flush the tlb caches...\r |
| | 62 | asm volatile(\r |
| | 63 | "stmdb sp!, {r0}\n\t"\r |
| | 64 | "mov r0, #0\n\t"\r |
| | 65 | "mcr 15, 0, r0, cr7, cr10, 4\n\t"\r |
| | 66 | "mcr 15, 0, r0, cr8, cr7, 0\n\t"\r |
| | 67 | "ldmia sp!, {r0}\n\t"\r |
| | 68 | );\r |
| | 69 | \r |
| | 70 | if (ret == 0)\r |
| | 71 | printk("MMU hack applied.\n");\r |
| | 72 | \r |
| | 73 | return 0;\r |
| | 74 | }\r |
| | 75 | \r |
| | 76 | static struct file_operations mmuhack_fops = {\r |
| | 77 | owner: THIS_MODULE,\r |
| | 78 | open: mmuhack_open,\r |
| | 79 | };\r |
| | 80 | \r |
| | 81 | \r |
| | 82 | static struct miscdevice mmuhack = {\r |
| | 83 | MMUHACK_MINOR, DEVICE_NAME, &mmuhack_fops\r |
| | 84 | };\r |
| | 85 | \r |
| | 86 | static int __init mmuhack_init(void)\r |
| | 87 | {\r |
| | 88 | misc_register(&mmuhack);\r |
| | 89 | /*\r |
| | 90 | printk("MMSP2 MMU Hack module.\n");\r |
| | 91 | */\r |
| | 92 | return 0;\r |
| | 93 | }\r |
| | 94 | \r |
| | 95 | static void __exit mmuhack_exit(void)\r |
| | 96 | {\r |
| | 97 | misc_deregister(&mmuhack);\r |
| | 98 | /*\r |
| | 99 | printk(KERN_ALERT "MMU Hack module removed.\n");\r |
| | 100 | */\r |
| | 101 | }\r |
| | 102 | \r |
| | 103 | module_init(mmuhack_init);\r |
| | 104 | module_exit(mmuhack_exit);\r |
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