11913091 |
1 | // vim:shiftwidth=2:expandtab |
2 | #include <stdio.h> |
3 | #include <string.h> |
4 | #include <sys/types.h> |
5 | #include <sys/stat.h> |
6 | #include <fcntl.h> |
7 | #include <sys/mman.h> |
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8 | #include <unistd.h> |
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9 | |
10 | #include "header.h" |
11 | #include "sys_cacheflush.h" |
12 | |
0881206b |
13 | #define strace(...) |
14 | |
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15 | static const unsigned int sig_open[] = { |
16 | 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900005 |
17 | }; |
18 | |
19 | static const unsigned int sig_mmap[] = { |
20 | 0xe92d000f, 0xe1a0000d, 0xef90005a, 0xe28dd010 |
21 | }; |
22 | |
23 | static const unsigned int sig_mmap_[] = { |
24 | 0xe52d5004, 0xe59d5008, 0xe52d4004, 0xe59d4008, |
25 | 0xe1b0ca05, 0x1a000006, 0xe1a05625, 0xef9000c0 |
26 | }; |
27 | |
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28 | static const unsigned int sig_read[] = { |
29 | 0xe59fc080, 0xe59cc000, 0xe33c0000, 0x1a000003, 0xef900003 |
30 | }; |
31 | |
32 | #define FAKE_DEVMEM_DEVICE 10001 |
33 | #define FAKE_DEVGPIO_DEVICE 10002 |
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34 | |
35 | static int w_open(const char *pathname, int flags, mode_t mode) |
36 | { |
37 | int ret; |
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38 | if (strcmp(pathname, "/dev/mem") == 0) |
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39 | ret = FAKE_DEVMEM_DEVICE; |
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40 | else if (strcmp(pathname, "/dev/GPIO") == 0) |
41 | ret = FAKE_DEVGPIO_DEVICE; |
42 | else |
43 | ret = open(pathname, flags, mode); |
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44 | |
0881206b |
45 | strace("open(%s) = %d\n", pathname, ret); |
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46 | return ret; |
47 | } |
48 | |
49 | static void *w_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) |
50 | { |
51 | void *ret; |
52 | if (fd != FAKE_DEVMEM_DEVICE) |
53 | ret = mmap(addr, length, prot, flags, fd, offset); |
54 | else |
55 | ret = emu_mmap_dev(length, prot, flags, offset); |
56 | |
0881206b |
57 | strace("mmap(%p, %x, %x, %x, %d, %lx) = %p\n", addr, length, prot, flags, fd, (long)offset, ret); |
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58 | return ret; |
59 | } |
60 | #define w_mmap_ w_mmap |
61 | |
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62 | ssize_t w_read(int fd, void *buf, size_t count) |
63 | { |
64 | ssize_t ret; |
65 | if (fd != FAKE_DEVGPIO_DEVICE) |
66 | return read(fd, buf, count); |
67 | |
68 | ret = emu_read_gpiodev(buf, count); |
69 | //printf("read(%d, %p, %d) = %d\n", fd, buf, count, ret); |
70 | return ret; |
71 | } |
72 | |
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73 | #define PATCH(f) { sig_##f, ARRAY_SIZE(sig_##f), w_##f } |
74 | |
75 | static const struct { |
76 | const unsigned int *sig; |
77 | size_t sig_cnt; |
78 | void *func; |
79 | } patches[] = { |
80 | PATCH(open), |
81 | PATCH(mmap), |
82 | PATCH(mmap_), // mmap using mmap2 syscall |
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83 | PATCH(read), |
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84 | }; |
85 | |
86 | void do_patches(void *ptr, unsigned int size) |
87 | { |
88 | int i, s; |
89 | |
90 | for (i = 0; i < ARRAY_SIZE(patches); i++) { |
91 | const unsigned int *sig = patches[i].sig; |
92 | unsigned int *seg = (void *)(((long)ptr + 3) & ~3); |
93 | unsigned int *seg_end = seg + size / 4; |
94 | unsigned int sig0 = sig[0]; |
95 | |
96 | for (; seg < seg_end; seg++) { |
97 | if (*seg != sig0) |
98 | continue; |
99 | |
100 | for (s = 1; s < patches[i].sig_cnt; s++) |
101 | if (seg[s] != sig[s]) |
102 | break; |
103 | |
104 | if (s == patches[i].sig_cnt) |
105 | goto found; |
106 | } |
107 | continue; |
108 | |
109 | found: |
110 | printf(" patch #%i @ %08x\n", i, (int)seg); |
111 | seg[0] = 0xe59ff000; // ldr pc, [pc] |
112 | seg[1] = 0; |
113 | seg[2] = (unsigned int)patches[i].func; |
114 | } |
115 | |
116 | sys_cacheflush(ptr, (char *)ptr + size); |
117 | } |
118 | |