22 lines
715 B
Perl
Executable File
22 lines
715 B
Perl
Executable File
#!/usr/bin/perl
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#
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# Compute Mac checksum for a ROM and compares it with the existing one.
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# Provide the ROM as an argument or on standard input.
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#
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# Copyright (C) 2023 Cameron Kaiser. All rights reserved.
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# BSD license.
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# oldvcr.blogspot.com
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eval "use bytes";
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$/ = \4; $actual = unpack("N", <>); printf("expected = 0x%08x\n", $actual);
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read(ARGV, $buf, 8388608);
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die("length of buffer is not even: @{[ length($buf) ]} bytes\n")
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if (length($buf) & 1);
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print "bytes read = @{[ length($buf) + 4 ]}\n";
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$checksum = 0;
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map { $checksum += $_ } unpack("n*", $buf); # map is faster than grep
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$checksum &= 4294967295;
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printf("computed = 0x%08x (%s)\n", $checksum,
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($checksum == $actual) ? "matches" : "DOES NOT MATCH");
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