Madeline Kistler / SDFileSystem2

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

FATFileSystem/MemFileSystem.h@0:812e8b0b2832, 2020-11-17 (annotated)

Committer:
mkistler
Date:
Tue Nov 17 20:30:08 2020 +0000
Revision:
0:812e8b0b2832
Final draft.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mkistler 0:812e8b0b2832 1 /* mbed Microcontroller Library - MemFileSystem
mkistler 0:812e8b0b2832 2 * Copyright (c) 2008, sford
mkistler 0:812e8b0b2832 3 */
mkistler 0:812e8b0b2832 4
mkistler 0:812e8b0b2832 5
mkistler 0:812e8b0b2832 6 #ifndef MBED_MEMFILESYSTEM_H
mkistler 0:812e8b0b2832 7 #define MBED_MEMFILESYSTEM_H
mkistler 0:812e8b0b2832 8
mkistler 0:812e8b0b2832 9 #include "FATFileSystem.h"
mkistler 0:812e8b0b2832 10
mkistler 0:812e8b0b2832 11 namespace mbed
mkistler 0:812e8b0b2832 12 {
mkistler 0:812e8b0b2832 13
mkistler 0:812e8b0b2832 14 class MemFileSystem : public FATFileSystem
mkistler 0:812e8b0b2832 15 {
mkistler 0:812e8b0b2832 16 public:
mkistler 0:812e8b0b2832 17
mkistler 0:812e8b0b2832 18 // 2000 sectors, each 512 bytes (malloced as required)
mkistler 0:812e8b0b2832 19 char *sectors[2000];
mkistler 0:812e8b0b2832 20
mkistler 0:812e8b0b2832 21 MemFileSystem(const char* name) : FATFileSystem(name) {
mkistler 0:812e8b0b2832 22 memset(sectors, 0, sizeof(sectors));
mkistler 0:812e8b0b2832 23 }
mkistler 0:812e8b0b2832 24
mkistler 0:812e8b0b2832 25 virtual ~MemFileSystem() {
mkistler 0:812e8b0b2832 26 for(int i = 0; i < 2000; i++) {
mkistler 0:812e8b0b2832 27 if(sectors[i]) {
mkistler 0:812e8b0b2832 28 free(sectors[i]);
mkistler 0:812e8b0b2832 29 }
mkistler 0:812e8b0b2832 30 }
mkistler 0:812e8b0b2832 31 }
mkistler 0:812e8b0b2832 32
mkistler 0:812e8b0b2832 33 // read a sector in to the buffer, return 0 if ok
mkistler 0:812e8b0b2832 34 virtual int disk_read(char *buffer, int sector) {
mkistler 0:812e8b0b2832 35 if(sectors[sector] == 0) {
mkistler 0:812e8b0b2832 36 // nothing allocated means sector is empty
mkistler 0:812e8b0b2832 37 memset(buffer, 0, 512);
mkistler 0:812e8b0b2832 38 } else {
mkistler 0:812e8b0b2832 39 memcpy(buffer, sectors[sector], 512);
mkistler 0:812e8b0b2832 40 }
mkistler 0:812e8b0b2832 41 return 0;
mkistler 0:812e8b0b2832 42 }
mkistler 0:812e8b0b2832 43
mkistler 0:812e8b0b2832 44 // write a sector from the buffer, return 0 if ok
mkistler 0:812e8b0b2832 45 virtual int disk_write(const char *buffer, int sector) {
mkistler 0:812e8b0b2832 46 // if buffer is zero deallocate sector
mkistler 0:812e8b0b2832 47 char zero[512];
mkistler 0:812e8b0b2832 48 memset(zero, 0, 512);
mkistler 0:812e8b0b2832 49 if(memcmp(zero, buffer, 512)==0) {
mkistler 0:812e8b0b2832 50 if(sectors[sector] != 0) {
mkistler 0:812e8b0b2832 51 free(sectors[sector]);
mkistler 0:812e8b0b2832 52 sectors[sector] = 0;
mkistler 0:812e8b0b2832 53 }
mkistler 0:812e8b0b2832 54 return 0;
mkistler 0:812e8b0b2832 55 }
mkistler 0:812e8b0b2832 56 // else allocate a sector if needed, and write
mkistler 0:812e8b0b2832 57 if(sectors[sector] == 0) {
mkistler 0:812e8b0b2832 58 char *sec = (char*)malloc(512);
mkistler 0:812e8b0b2832 59 if(sec==0) {
mkistler 0:812e8b0b2832 60 return 1; // out of memory
mkistler 0:812e8b0b2832 61 }
mkistler 0:812e8b0b2832 62 sectors[sector] = sec;
mkistler 0:812e8b0b2832 63 }
mkistler 0:812e8b0b2832 64 memcpy(sectors[sector], buffer, 512);
mkistler 0:812e8b0b2832 65 return 0;
mkistler 0:812e8b0b2832 66 }
mkistler 0:812e8b0b2832 67
mkistler 0:812e8b0b2832 68 // return the number of sectors
mkistler 0:812e8b0b2832 69 virtual int disk_sectors() {
mkistler 0:812e8b0b2832 70 return sizeof(sectors)/sizeof(sectors[0]);
mkistler 0:812e8b0b2832 71 }
mkistler 0:812e8b0b2832 72
mkistler 0:812e8b0b2832 73 };
mkistler 0:812e8b0b2832 74
mkistler 0:812e8b0b2832 75 }
mkistler 0:812e8b0b2832 76
mkistler 0:812e8b0b2832 77 #endif