FAT12 read only file system
Fork of FATFileSystem by
F12RFileHandle.cpp@9:d92e85b739a7, 2016-04-10 (annotated)
- Committer:
- va009039
- Date:
- Sun Apr 10 07:39:37 2016 +0900
- Revision:
- 9:d92e85b739a7
- Parent:
- 8:6c6acf81ff08
fix number_of_fats.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
va009039 |
7:f9f52d9c0c57 | 1 | /* mbed Microcontroller Library |
va009039 |
7:f9f52d9c0c57 | 2 | * Copyright (c) 2006-2016 ARM Limited |
va009039 |
7:f9f52d9c0c57 | 3 | * |
va009039 |
7:f9f52d9c0c57 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
va009039 |
7:f9f52d9c0c57 | 5 | * of this software and associated documentation files (the "Software"), to deal |
va009039 |
7:f9f52d9c0c57 | 6 | * in the Software without restriction, including without limitation the rights |
va009039 |
7:f9f52d9c0c57 | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
va009039 |
7:f9f52d9c0c57 | 8 | * copies of the Software, and to permit persons to whom the Software is |
va009039 |
7:f9f52d9c0c57 | 9 | * furnished to do so, subject to the following conditions: |
va009039 |
7:f9f52d9c0c57 | 10 | * |
va009039 |
7:f9f52d9c0c57 | 11 | * The above copyright notice and this permission notice shall be included in |
va009039 |
7:f9f52d9c0c57 | 12 | * all copies or substantial portions of the Software. |
va009039 |
7:f9f52d9c0c57 | 13 | * |
va009039 |
7:f9f52d9c0c57 | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
va009039 |
7:f9f52d9c0c57 | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
va009039 |
7:f9f52d9c0c57 | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
va009039 |
7:f9f52d9c0c57 | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
va009039 |
7:f9f52d9c0c57 | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
va009039 |
7:f9f52d9c0c57 | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
va009039 |
7:f9f52d9c0c57 | 20 | * SOFTWARE. |
va009039 |
7:f9f52d9c0c57 | 21 | */ |
va009039 |
7:f9f52d9c0c57 | 22 | #include <algorithm> |
va009039 |
7:f9f52d9c0c57 | 23 | #include "F12RFileHandle.h" |
va009039 |
7:f9f52d9c0c57 | 24 | #include "fsdebug.h" |
va009039 |
7:f9f52d9c0c57 | 25 | |
va009039 |
7:f9f52d9c0c57 | 26 | F12RFileHandle::F12RFileHandle(F12RFileSystem& fs_, uint32_t d):fs(fs_) { |
va009039 |
7:f9f52d9c0c57 | 27 | pos = 0; |
va009039 |
7:f9f52d9c0c57 | 28 | cluster = fs.storage_peek(d + 26, 2); |
va009039 |
7:f9f52d9c0c57 | 29 | file_length = fs.storage_peek(d + 28, 4); |
va009039 |
7:f9f52d9c0c57 | 30 | FS_DBG("cluster=%d", cluster); |
va009039 |
7:f9f52d9c0c57 | 31 | FS_DBG("file_length=%d", file_length); |
va009039 |
7:f9f52d9c0c57 | 32 | } |
va009039 |
7:f9f52d9c0c57 | 33 | |
va009039 |
7:f9f52d9c0c57 | 34 | int F12RFileHandle::close() { |
va009039 |
7:f9f52d9c0c57 | 35 | delete this; |
va009039 |
7:f9f52d9c0c57 | 36 | return 0; |
va009039 |
7:f9f52d9c0c57 | 37 | } |
va009039 |
7:f9f52d9c0c57 | 38 | |
va009039 |
7:f9f52d9c0c57 | 39 | ssize_t F12RFileHandle::write(const void* buffer, size_t length) { |
va009039 |
7:f9f52d9c0c57 | 40 | return -1; |
va009039 |
7:f9f52d9c0c57 | 41 | } |
va009039 |
7:f9f52d9c0c57 | 42 | |
va009039 |
7:f9f52d9c0c57 | 43 | ssize_t F12RFileHandle::read(void* buffer, size_t length) { |
va009039 |
7:f9f52d9c0c57 | 44 | FS_DBG("length=%d", length); |
va009039 |
7:f9f52d9c0c57 | 45 | ssize_t n = 0; |
va009039 |
7:f9f52d9c0c57 | 46 | while(n < length && pos < file_length) { |
va009039 |
8:6c6acf81ff08 | 47 | uint32_t chunk = std::min((filesize_t)length - n, file_length - pos); |
va009039 |
7:f9f52d9c0c57 | 48 | chunk = std::min(chunk, fs.cluster_tail(pos)); |
va009039 |
7:f9f52d9c0c57 | 49 | FS_TEST_ASSERT(cluster >= 2 && cluster < 0xff8); |
va009039 |
8:6c6acf81ff08 | 50 | fs.storage->Read(fs.base_data + (cluster-2)*fs.cluster_size + fs.cluster_head(pos), (uint8_t*)buffer + n, chunk); |
va009039 |
7:f9f52d9c0c57 | 51 | pos += chunk; |
va009039 |
7:f9f52d9c0c57 | 52 | if (fs.cluster_head(pos) == 0) { |
va009039 |
7:f9f52d9c0c57 | 53 | cluster = fs.fat_read(cluster); |
va009039 |
7:f9f52d9c0c57 | 54 | } |
va009039 |
7:f9f52d9c0c57 | 55 | n += chunk; |
va009039 |
7:f9f52d9c0c57 | 56 | } |
va009039 |
7:f9f52d9c0c57 | 57 | return n; |
va009039 |
7:f9f52d9c0c57 | 58 | } |
va009039 |
7:f9f52d9c0c57 | 59 | |
va009039 |
7:f9f52d9c0c57 | 60 | int F12RFileHandle::isatty() { |
va009039 |
7:f9f52d9c0c57 | 61 | return 0; |
va009039 |
7:f9f52d9c0c57 | 62 | } |
va009039 |
7:f9f52d9c0c57 | 63 | |
va009039 |
7:f9f52d9c0c57 | 64 | off_t F12RFileHandle::lseek(off_t position, int whence) { |
va009039 |
7:f9f52d9c0c57 | 65 | FS_DBG("position=%d whence=%d", (uint32_t)position, whence); |
va009039 |
7:f9f52d9c0c57 | 66 | return -1; |
va009039 |
7:f9f52d9c0c57 | 67 | } |
va009039 |
7:f9f52d9c0c57 | 68 | |
va009039 |
7:f9f52d9c0c57 | 69 | int F12RFileHandle::fsync() { |
va009039 |
7:f9f52d9c0c57 | 70 | return 0; |
va009039 |
7:f9f52d9c0c57 | 71 | } |
va009039 |
7:f9f52d9c0c57 | 72 | |
va009039 |
7:f9f52d9c0c57 | 73 | off_t F12RFileHandle::flen() { |
va009039 |
7:f9f52d9c0c57 | 74 | FS_DBG("file_length=%d", file_length); |
va009039 |
7:f9f52d9c0c57 | 75 | return file_length; |
va009039 |
7:f9f52d9c0c57 | 76 | } |