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| -rw-r--r-- | doc/usage/cmd/cmp.rst | 105 | ||||
| -rw-r--r-- | doc/usage/index.rst | 1 |
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diff --git a/doc/usage/cmd/cmp.rst b/doc/usage/cmd/cmp.rst new file mode 100644 index 00000000000..241320d3289 --- /dev/null +++ b/doc/usage/cmd/cmp.rst @@ -0,0 +1,105 @@ +.. SPDX-License-Identifier: GPL-2.0+: + +cmp command +=========== + +Synopsis +-------- + +:: + + cmp [.b, .w, .l, .q] addr1 addr2 count + +Description +----------- + +The cmp command is used to compare two memory areas. By default it works on +four byte tuples. By appending .b, .w, .l, .q the size of the tuples is +controlled: + +cmp.b + compare 1 byte tuples + +cmp.w + compare 2 byte tuples + +cmp.l + compare 4 byte tuples + +cmp.q + compare 8 byte tuples + +The parameters are used as follows: + +addr1 + Address of the first memory area. + +addr2 + Address of the second memory area. + +count + Number of bytes to compare (as hexadecimal number). + +Example +------- + +In the example below the strings "Hello world\n" and "Hello World\n" are written +to memory and then compared. + +:: + + => mm.b 0x1000000 + 01000000: 00 ? 48 + 01000001: 00 ? 65 + 01000002: 00 ? 6c + 01000003: 00 ? 6c + 01000004: 00 ? 6f + 01000005: 00 ? 20 + 01000006: 00 ? 77 + 01000007: 00 ? 6f + 01000008: 00 ? 72 + 01000009: 00 ? 6c + 0100000a: 00 ? 64 + 0100000b: 00 ? 0d + 0100000c: 00 ? => <INTERRUPT> + => mm.b 0x101000 + 00101000: 00 ? 48 + 00101001: 00 ? 65 + 00101002: 00 ? 6c + 00101003: 00 ? 6c + 00101004: 00 ? 6f + 00101005: 00 ? 20 + 00101006: 00 ? 57 + 00101007: 00 ? 6f + 00101008: 00 ? 72 + 00101009: 00 ? 6c + 0010100a: 00 ? 64 + 0010100b: 00 ? 0d + 0010100c: 00 ? => <INTERRUPT> + => cmp 0x1000000 0x101000 0xc + word at 0x01000004 (0x6f77206f) != word at 0x00101004 (0x6f57206f) + Total of 1 word(s) were the same + => cmp.b 0x1000000 0x101000 0xc + byte at 0x01000006 (0x77) != byte at 0x00101006 (0x57) + Total of 6 byte(s) were the same + => cmp.w 0x1000000 0x101000 0xc + halfword at 0x01000006 (0x6f77) != halfword at 0x00101006 (0x6f57) + Total of 3 halfword(s) were the same + => cmp.l 0x1000000 0x101000 0xc + word at 0x01000004 (0x6f77206f) != word at 0x00101004 (0x6f57206f) + Total of 1 word(s) were the same + => cmp.q 0x1000000 0x101000 0xc + double word at 0x01000000 (0x6f77206f6c6c6548) != double word at 0x00101000 (0x6f57206f6c6c6548) + Total of 0 double word(s) were the same + +Configuration +------------- + +The cmp command is only available if CONFIG_CMD_MEMORY=y. The cmp.q command is +only available if additionally CONFIG_MEM_SUPPORT_64BIT_DATA=y. + +Return value +------------ + +The return value $? is true (0) if the compared memory areas are equal. +The reutrn value is false (1) if the compared memory areas differ. diff --git a/doc/usage/index.rst b/doc/usage/index.rst index 815b032247f..d6283fab8eb 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -35,6 +35,7 @@ Shell commands cmd/cat cmd/cbsysinfo cmd/cls + cmd/cmp cmd/conitrace cmd/cyclic cmd/dm |