1// SPDX-License-Identifier: GPL-3.0-or-later
2
3#include "ramdisk.hpp"
4
5#include <abi-bits/vm-flags.h>
6#include <string.h>
7#include <sys/mman.h>
8
9RAMDisk::RAMDisk(const size_t nbytes) : m_nbytes(nbytes), m_nblocks(nbytes / BLOCKDEV_BLOCK_SIZE)
10{
11 m_data = (uint8_t *) mmap(NULL, size: nbytes, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, fd: -1, offset: 0);
12}
13
14RAMDisk::~RAMDisk()
15{
16 munmap(addr: m_data, size: m_nbytes);
17}
18
19size_t RAMDisk::read_block(const size_t block, const size_t nblocks, uint8_t *buf)
20{
21 if (block + nblocks > m_nblocks)
22 return 0;
23
24 memcpy(dest: buf, src: m_data + block * BLOCKDEV_BLOCK_SIZE, size: nblocks * BLOCKDEV_BLOCK_SIZE);
25 return nblocks;
26}
27
28size_t RAMDisk::write_block(const size_t block, const size_t nblocks, const uint8_t *buf)
29{
30 if (block + nblocks > m_nblocks)
31 return 0;
32
33 memcpy(dest: m_data + block * BLOCKDEV_BLOCK_SIZE, src: buf, size: nblocks * BLOCKDEV_BLOCK_SIZE);
34 return nblocks;
35}
36