Revised to support ability to have both SD and USB drives mounted.
Dependents: Multi-FileSystem Multi-FileSystem
Fork of FATFileSystem by
MemFileSystem.h
- Committer:
- WiredHome
- Date:
- 2017-07-29
- Revision:
- 12:d816f503fc6f
- Parent:
- 11:2f7ad4af3ec1
File content as of revision 12:d816f503fc6f:
/* mbed Microcontroller Library - MemFileSystem * Copyright (c) 2008, sford */ #ifndef MBED_MEMFILESYSTEM_H #define MBED_MEMFILESYSTEM_H #include "FATFileSystem.h" // 4 Bytes / Sector, each 512 Bytes - malloc'd as required // Value was 2000 (8K) #define NUM_SECTORS 100 #define SECTOR_SIZE 512 // moved the zeroed RAM buffer to flash, // so it doesn't waste precious RAM static const char zero[SECTOR_SIZE] = {0}; namespace mbed { class MemFileSystem : public FATFileSystem { public: // NUM_SECTORS sectors, each 512 bytes (malloced as required) char *sectors[NUM_SECTORS]; MemFileSystem(const char* name) : FATFileSystem(name) { memset(sectors, 0, sizeof(sectors)); } virtual ~MemFileSystem() { for(int i = 0; i < NUM_SECTORS; i++) { if(sectors[i]) { free(sectors[i]); } } } // read a sector in to the buffer, return 0 if ok virtual int disk_read(char *buffer, int sector) { if(sectors[sector] == 0) { // nothing allocated means sector is empty memset(buffer, 0, SECTOR_SIZE); } else { memcpy(buffer, sectors[sector], SECTOR_SIZE); } return 0; } // write a sector from the buffer, return 0 if ok virtual int disk_write(const char *buffer, int sector) { // if buffer is zero deallocate sector //char zero[SECTOR_SIZE] = {0}; // DS this used to be a ram buffer //memset(zero, 0, SECTOR_SIZE); if(memcmp(zero, buffer, SECTOR_SIZE)==0) { if(sectors[sector] != 0) { free(sectors[sector]); sectors[sector] = 0; } return 0; } // else allocate a sector if needed, and write if(sectors[sector] == 0) { char *sec = (char*)malloc(SECTOR_SIZE); if(sec==0) { return 1; // out of memory } sectors[sector] = sec; } memcpy(sectors[sector], buffer, SECTOR_SIZE); return 0; } // return the number of sectors virtual int disk_sectors() { return sizeof(sectors)/sizeof(sectors[0]); } }; } #endif