Added memory functions (not tested)

This commit is contained in:
Eric-Paul Ickhorn 2023-12-01 16:36:36 +01:00
parent 0e36b43793
commit de3ac20422
Signed by: epickh
GPG Key ID: F5EBBE013924D95F
2 changed files with 92 additions and 0 deletions

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#ifndef RR_RUNES_H
#define RR_RUNES_H
#include <librr/types.h>
/// @brief Tests if two memory regions overlap partially or completely.
/// @param block1 Block to check for overlapping with block2.
// If the address of this block is higher than that of block2, the blocks will be swapped internally.
/// @param length1 The length of the first block.
/// @param block2 The second block to check for overlapping.
/// @param length2
/// @return Whether the two blocks overlap.
bool_t rr_mem_overlap(void *block1, usz_t length1, void *block2, usz_t length2);
/// @brief Checks if two memory blocks contain the equal data.
/// @param block1 Address of the data to be checked for equality with 'block2'
/// @param block2 Address of the other memory block. In cases where there is a clear correct version,
/// this should be the correct data to be checked against.
/// @param count How many bytes will be checked.
/// @return
bool_t rr_memequ(void *block1, void *block2, usz_t count);
/// @brief Sets all bytes in a memory region all to one byte
/// @param destination Address to the memory region to fill with one byte
/// @param count Number of bytes to set; length of 'destination'
/// @param value Value to write to every bte of 'destination'.
void rr_memset(void *destination, usz_t count, u8_t value);
/// @brief Repeats a sequence until a number of bytes was filled, potentially only writing a sequence half-way.
/// @attention The sequence cannot be contained in the destination.
/// @param destination Address in memory in which the sequence will be repeated.
/// @param num_bytes How many bytes of the destination should be filled. The last sequence can be partially finished.
/// @param sequence Sequence of bytes which will be written to destination.
/// @param len_sequence Length of 'sequence'
/// @return The number of attempted or partial repetitions which have been performed.
usz_t rr_memrep(void *destination, usz_t num_bytes, void *sequence, usz_t len_sequence);
#endif // LIBRR_RUNES_H

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code/src-c/memory.c Normal file
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#include <librr/memory.h>
bool_t rr_mem_overlap(void *block1, usz_t length1, void *block2, usz_t length2)
{
// Make block1 always be before block2
if(block1 > block2)
{
void *block_backup = block2;
usz_t length_backup = length2;
block2 = block1;
length2 = length1;
block1 = block_backup;
length1 = length_backup;
}
usz_t start1 = (usz_t) block1;
usz_t start2 = (usz_t) block2;
usz_t end2 = start2 + length2;
if(end2 > start1)
{
return TRUE;
}
return FALSE;
}
bool_t rr_memequ(void *block1, void *block2, usz_t count)
{
u8_t *block1_8 = block1;
u8_t *block2_8 = block2;
for(usz_t index = 0; index < count; ++index)
if(block1_8[index] != block2_8[index]) return FALSE;
return TRUE;
}
void rr_memset(void *destination, usz_t count, u8_t value)
{
u8_t *destination_8 = destination;
for(usz_t index = 0; index < count; ++index)
destination_8[index] = value;
}
usz_t rr_memrep(void *destination, usz_t num_bytes, void *sequence, usz_t len_sequence)
{
if(rr_mem_overlap(destination, num_bytes, sequence, len_sequence)) return 0;
u8_t *destination_8 = destination;
u8_t *sequence_8 = sequence;
for(usz_t index = 0; index < num_bytes; ++index)
destination_8[index] = sequence_8[index % len_sequence];
return (num_bytes / len_sequence) // How many full repetitions are performed
+ ((num_bytes % len_sequence) != 0); // One more if a partial repetiton is done
}