Contents of /trunk/mkinitrd-magellan/busybox/miscutils/devmem.c
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Revision 816 -
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Fri Apr 24 18:33:46 2009 UTC (15 years, 5 months ago) by niro
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Fri Apr 24 18:33:46 2009 UTC (15 years, 5 months ago) by niro
File MIME type: text/plain
File size: 3429 byte(s)
-updated to busybox-1.13.4
1 | /* |
2 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
3 | * Copyright (C) 2000, Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl) |
4 | * Copyright (C) 2008, BusyBox Team. -solar 4/26/08 |
5 | */ |
6 | |
7 | #include "libbb.h" |
8 | |
9 | int devmem_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
10 | int devmem_main(int argc UNUSED_PARAM, char **argv) |
11 | { |
12 | void *map_base, *virt_addr; |
13 | uint64_t read_result; |
14 | uint64_t writeval = writeval; /* for compiler */ |
15 | off_t target; |
16 | unsigned page_size = getpagesize(); |
17 | int fd; |
18 | int width = 8 * sizeof(int); |
19 | |
20 | /* devmem ADDRESS [WIDTH [VALUE]] */ |
21 | // TODO: options? |
22 | // -r: read and output only the value in hex, with 0x prefix |
23 | // -w: write only, no reads before or after, and no output |
24 | // or make this behavior default? |
25 | // Let's try this and see how users react. |
26 | |
27 | /* ADDRESS */ |
28 | if (!argv[1]) |
29 | bb_show_usage(); |
30 | errno = 0; |
31 | target = bb_strtoull(argv[1], NULL, 0); /* allows hex, oct etc */ |
32 | |
33 | /* WIDTH */ |
34 | if (argv[2]) { |
35 | if (isdigit(argv[2][0]) || argv[2][1]) |
36 | width = xatou(argv[2]); |
37 | else { |
38 | static const char bhwl[] ALIGN1 = "bhwl"; |
39 | static const uint8_t sizes[] ALIGN1 = { |
40 | 8 * sizeof(char), |
41 | 8 * sizeof(short), |
42 | 8 * sizeof(int), |
43 | 8 * sizeof(long), |
44 | 0 /* bad */ |
45 | }; |
46 | width = strchrnul(bhwl, (argv[2][0] | 0x20)) - bhwl; |
47 | width = sizes[width]; |
48 | } |
49 | /* VALUE */ |
50 | if (argv[3]) |
51 | writeval = bb_strtoull(argv[3], NULL, 0); |
52 | } else { /* argv[2] == NULL */ |
53 | /* make argv[3] to be a valid thing to use */ |
54 | argv--; |
55 | } |
56 | if (errno) |
57 | bb_show_usage(); /* bb_strtouXX failed */ |
58 | |
59 | fd = xopen("/dev/mem", argv[3] ? (O_RDWR | O_SYNC) : (O_RDONLY | O_SYNC)); |
60 | map_base = mmap(NULL, |
61 | page_size * 2 /* in case value spans page */, |
62 | argv[3] ? (PROT_READ | PROT_WRITE) : PROT_READ, |
63 | MAP_SHARED, |
64 | fd, |
65 | target & ~(off_t)(page_size - 1)); |
66 | if (map_base == MAP_FAILED) |
67 | bb_perror_msg_and_die("mmap"); |
68 | |
69 | // printf("Memory mapped at address %p.\n", map_base); |
70 | |
71 | virt_addr = (char*)map_base + (target & (page_size - 1)); |
72 | |
73 | if (!argv[3]) { |
74 | switch (width) { |
75 | case 8: |
76 | read_result = *(volatile uint8_t*)virt_addr; |
77 | break; |
78 | case 16: |
79 | read_result = *(volatile uint16_t*)virt_addr; |
80 | break; |
81 | case 32: |
82 | read_result = *(volatile uint32_t*)virt_addr; |
83 | break; |
84 | case 64: |
85 | read_result = *(volatile uint64_t*)virt_addr; |
86 | break; |
87 | default: |
88 | bb_error_msg_and_die("bad width"); |
89 | } |
90 | // printf("Value at address 0x%"OFF_FMT"X (%p): 0x%llX\n", |
91 | // target, virt_addr, |
92 | // (unsigned long long)read_result); |
93 | /* Zero-padded output shows the width of access just done */ |
94 | printf("0x%0*llX\n", (width >> 2), (unsigned long long)read_result); |
95 | } else { |
96 | switch (width) { |
97 | case 8: |
98 | *(volatile uint8_t*)virt_addr = writeval; |
99 | // read_result = *(volatile uint8_t*)virt_addr; |
100 | break; |
101 | case 16: |
102 | *(volatile uint16_t*)virt_addr = writeval; |
103 | // read_result = *(volatile uint16_t*)virt_addr; |
104 | break; |
105 | case 32: |
106 | *(volatile uint32_t*)virt_addr = writeval; |
107 | // read_result = *(volatile uint32_t*)virt_addr; |
108 | break; |
109 | case 64: |
110 | *(volatile uint64_t*)virt_addr = writeval; |
111 | // read_result = *(volatile uint64_t*)virt_addr; |
112 | break; |
113 | default: |
114 | bb_error_msg_and_die("bad width"); |
115 | } |
116 | // printf("Written 0x%llX; readback 0x%llX\n", |
117 | // (unsigned long long)writeval, |
118 | // (unsigned long long)read_result); |
119 | } |
120 | |
121 | if (ENABLE_FEATURE_CLEAN_UP) { |
122 | if (munmap(map_base, page_size * 2) == -1) |
123 | bb_perror_msg_and_die("munmap"); |
124 | close(fd); |
125 | } |
126 | |
127 | return EXIT_SUCCESS; |
128 | } |