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