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
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
/*
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <gpxe/blockdev.h>
#include <gpxe/ramdisk.h>
/**
* @file
*
* RAM disks
*
*/
static inline __attribute__ (( always_inline )) struct ramdisk *
block_to_ramdisk ( struct block_device *blockdev ) {
return container_of ( blockdev, struct ramdisk, blockdev );
}
/**
* Read block
*
* @v blockdev Block device
* @v block Block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static int ramdisk_read ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
unsigned long offset = ( block * blockdev->blksize );
unsigned long length = ( count * blockdev->blksize );
DBGC ( ramdisk, "RAMDISK %p reading [%lx,%lx)\n",
ramdisk, offset, length );
memcpy_user ( buffer, 0, ramdisk->data, offset, length );
return 0;
}
/**
* Write block
*
* @v blockdev Block device
* @v block Block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static int ramdisk_write ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
unsigned long offset = ( block * blockdev->blksize );
unsigned long length = ( count * blockdev->blksize );
DBGC ( ramdisk, "RAMDISK %p writing [%lx,%lx)\n",
ramdisk, offset, length );
memcpy_user ( ramdisk->data, offset, buffer, 0, length );
return 0;
}
static struct block_device_operations ramdisk_operations = {
.read = ramdisk_read,
.write = ramdisk_write
};
int init_ramdisk ( struct ramdisk *ramdisk, userptr_t data, size_t len,
unsigned int blksize ) {
if ( ! blksize )
blksize = 512;
ramdisk->data = data;
ramdisk->blockdev.op = &ramdisk_operations;
ramdisk->blockdev.blksize = blksize;
ramdisk->blockdev.blocks = ( len / blksize );
return 0;
}
|
