blob: 7ed57fa2b117f9a5fe7ea86651e1fa15b805c026 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
#ifndef BUFFER_H
#define BUFFER_H
#include "stdint.h"
/*
* Free blocks in the buffer start with a "tail byte". If non-zero,
* this byte indicates that the free block is the tail of the buffer,
* i.e. occupies all the remaining space up to the end of the buffer.
* When the tail byte is non-zero, it indicates that the remainder of
* the descriptor (the struct buffer_free_block) follows the tail
* byte.
*
* This scheme is necessary because we may end up with a tail that is
* smaller than a struct buffer_free_block.
*
*/
struct buffer_free_block {
char tail;
physaddr_t next_free;
physaddr_t end;
} __attribute__ (( packed ));
struct buffer {
physaddr_t start;
physaddr_t end;
physaddr_t first_free;
};
/* Functions in buffer.c */
extern void init_buffer ( struct buffer *buffer, physaddr_t start,
size_t len );
extern off_t fill_buffer ( struct buffer *buffer, void *data,
off_t offset, size_t len );
#endif /* BUFFER_H */
|
