Difference between revisions of "/tmp/nandTest.dat"
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Hallowizer (talk | contribs) (→Algorithm: seems like this function is just the normal rand function in the sdk) |
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'''/tmp/nandTest.dat''' is a 25.6MB file created during the factory process to test reading and writing the NAND. It contains a specific pseudorandom pattern. The contents can be downloaded [http://static.hackmii.com/garbage.7z here]. | '''/tmp/nandTest.dat''' is a 25.6MB file created during the factory process to test reading and writing the NAND. It contains a specific pseudorandom pattern. The contents can be downloaded [http://static.hackmii.com/garbage.7z here]. | ||
| + | |||
| + | The program that uses this file copies the file across the NAND using [[:/dev/flash]] and copies it back, allowing bad copies to be identified. | ||
| + | |||
| + | This program has the side effect of overwriting most of the earlier factory remnants with this pattern, making factory analysis more difficult. | ||
Like other contents of [[:/tmp]], it is erased on every [[boot2|boot]] and [[IOS]] reload. | Like other contents of [[:/tmp]], it is erased on every [[boot2|boot]] and [[IOS]] reload. | ||
== Algorithm == | == Algorithm == | ||
| − | + | This file is generated by the [[SDK]] <code>rand</code> function. | |
s32 seed = 1; | s32 seed = 1; | ||
s16 rand(void) { | s16 rand(void) { | ||
Latest revision as of 04:40, 6 August 2022
/tmp/nandTest.dat is a 25.6MB file created during the factory process to test reading and writing the NAND. It contains a specific pseudorandom pattern. The contents can be downloaded here.
The program that uses this file copies the file across the NAND using /dev/flash and copies it back, allowing bad copies to be identified.
This program has the side effect of overwriting most of the earlier factory remnants with this pattern, making factory analysis more difficult.
Like other contents of /tmp, it is erased on every boot and IOS reload.
Algorithm
This file is generated by the SDK rand function.
s32 seed = 1;
s16 rand(void) {
seed *= 0x41C64E6D;
seed += 12345;
return (s16) seed >> 16;
}
u8 getRandomChar(void) {
return rand() >> 8;
}
