file_copier - application that helps to copy file between SD an…

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Tedd OKANO / Mbed 2 deprecated file_copier

application that helps to copy file between SD and mbed_local. insert/remove SD card is too troublesome for me. And also, this is a simple sample of the fread/fwrite

Dependencies: mbed

SDFileSystem.cpp@1:1a76280274de, 2010-09-22 (annotated)

Committer:: okano
Date:: Wed Sep 22 05:26:10 2010 +0000
Revision:: 1:1a76280274de
Parent:: 0:81b440aaf221

Who changed what in which revision?

User	Revision	Line number	New contents of line
okano	0:81b440aaf221	1	/* mbed Microcontroller Library - SDFileSystem
okano	0:81b440aaf221	2	* Copyright (c) 2008-2009, sford
okano	0:81b440aaf221	3	*
okano	0:81b440aaf221	4	* Introduction
okano	0:81b440aaf221	5	* ------------
okano	0:81b440aaf221	6	* SD and MMC cards support a number of interfaces, but common to them all
okano	0:81b440aaf221	7	* is one based on SPI. This is the one I'm implmenting because it means
okano	0:81b440aaf221	8	* it is much more portable even though not so performant, and we already
okano	0:81b440aaf221	9	* have the mbed SPI Interface!
okano	0:81b440aaf221	10	*
okano	0:81b440aaf221	11	* The main reference I'm using is Chapter 7, "SPI Mode" of:
okano	0:81b440aaf221	12	* http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
okano	0:81b440aaf221	13	*
okano	0:81b440aaf221	14	* SPI Startup
okano	0:81b440aaf221	15	* -----------
okano	0:81b440aaf221	16	* The SD card powers up in SD mode. The SPI interface mode is selected by
okano	0:81b440aaf221	17	* asserting CS low and sending the reset command (CMD0). The card will
okano	0:81b440aaf221	18	* respond with a (R1) response.
okano	0:81b440aaf221	19	*
okano	0:81b440aaf221	20	* CMD8 is optionally sent to determine the voltage range supported, and
okano	0:81b440aaf221	21	* indirectly determine whether it is a version 1.x SD/non-SD card or
okano	0:81b440aaf221	22	* version 2.x. I'll just ignore this for now.
okano	0:81b440aaf221	23	*
okano	0:81b440aaf221	24	* ACMD41 is repeatedly issued to initialise the card, until "in idle"
okano	0:81b440aaf221	25	* (bit 0) of the R1 response goes to '0', indicating it is initialised.
okano	0:81b440aaf221	26	*
okano	0:81b440aaf221	27	* You should also indicate whether the host supports High Capicity cards,
okano	0:81b440aaf221	28	* and check whether the card is high capacity - i'll also ignore this
okano	0:81b440aaf221	29	*
okano	0:81b440aaf221	30	* SPI Protocol
okano	0:81b440aaf221	31	* ------------
okano	0:81b440aaf221	32	* The SD SPI protocol is based on transactions made up of 8-bit words, with
okano	0:81b440aaf221	33	* the host starting every bus transaction by asserting the CS signal low. The
okano	0:81b440aaf221	34	* card always responds to commands, data blocks and errors.
okano	0:81b440aaf221	35	*
okano	0:81b440aaf221	36	* The protocol supports a CRC, but by default it is off (except for the
okano	0:81b440aaf221	37	* first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
okano	0:81b440aaf221	38	* I'll leave the CRC off I think!
okano	0:81b440aaf221	39	*
okano	0:81b440aaf221	40	* Standard capacity cards have variable data block sizes, whereas High
okano	0:81b440aaf221	41	* Capacity cards fix the size of data block to 512 bytes. I'll therefore
okano	0:81b440aaf221	42	* just always use the Standard Capacity cards with a block size of 512 bytes.
okano	0:81b440aaf221	43	* This is set with CMD16.
okano	0:81b440aaf221	44	*
okano	0:81b440aaf221	45	* You can read and write single blocks (CMD17, CMD25) or multiple blocks
okano	0:81b440aaf221	46	* (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
okano	0:81b440aaf221	47	* the card gets a read command, it responds with a response token, and then
okano	0:81b440aaf221	48	* a data token or an error.
okano	0:81b440aaf221	49	*
okano	0:81b440aaf221	50	* SPI Command Format
okano	0:81b440aaf221	51	* ------------------
okano	0:81b440aaf221	52	* Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
okano	0:81b440aaf221	53	*
okano	0:81b440aaf221	54	* +---------------+------------+------------+-----------+----------+--------------+
okano	0:81b440aaf221	55	* \| 01 \| cmd[5:0] \| arg[31:24] \| arg[23:16] \| arg[15:8] \| arg[7:0] \| crc[6:0] \| 1 \|
okano	0:81b440aaf221	56	* +---------------+------------+------------+-----------+----------+--------------+
okano	0:81b440aaf221	57	*
okano	0:81b440aaf221	58	* As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
okano	0:81b440aaf221	59	*
okano	0:81b440aaf221	60	* All Application Specific commands shall be preceded with APP_CMD (CMD55).
okano	0:81b440aaf221	61	*
okano	0:81b440aaf221	62	* SPI Response Format
okano	0:81b440aaf221	63	* -------------------
okano	0:81b440aaf221	64	* The main response format (R1) is a status byte (normally zero). Key flags:
okano	0:81b440aaf221	65	* idle - 1 if the card is in an idle state/initialising
okano	0:81b440aaf221	66	* cmd - 1 if an illegal command code was detected
okano	0:81b440aaf221	67	*
okano	0:81b440aaf221	68	* +-------------------------------------------------+
okano	0:81b440aaf221	69	* R1 \| 0 \| arg \| addr \| seq \| crc \| cmd \| erase \| idle \|
okano	0:81b440aaf221	70	* +-------------------------------------------------+
okano	0:81b440aaf221	71	*
okano	0:81b440aaf221	72	* R1b is the same, except it is followed by a busy signal (zeros) until
okano	0:81b440aaf221	73	* the first non-zero byte when it is ready again.
okano	0:81b440aaf221	74	*
okano	0:81b440aaf221	75	* Data Response Token
okano	0:81b440aaf221	76	* -------------------
okano	0:81b440aaf221	77	* Every data block written to the card is acknowledged by a byte
okano	0:81b440aaf221	78	* response token
okano	0:81b440aaf221	79	*
okano	0:81b440aaf221	80	* +----------------------+
okano	0:81b440aaf221	81	* \| xxx \| 0 \| status \| 1 \|
okano	0:81b440aaf221	82	* +----------------------+
okano	0:81b440aaf221	83	* 010 - OK!
okano	0:81b440aaf221	84	* 101 - CRC Error
okano	0:81b440aaf221	85	* 110 - Write Error
okano	0:81b440aaf221	86	*
okano	0:81b440aaf221	87	* Single Block Read and Write
okano	0:81b440aaf221	88	* ---------------------------
okano	0:81b440aaf221	89	*
okano	0:81b440aaf221	90	* Block transfers have a byte header, followed by the data, followed
okano	0:81b440aaf221	91	* by a 16-bit CRC. In our case, the data will always be 512 bytes.
okano	0:81b440aaf221	92	*
okano	0:81b440aaf221	93	* +------+---------+---------+- - - -+---------+-----------+----------+
okano	0:81b440aaf221	94	* \| 0xFE \| data[0] \| data[1] \| \| data[n] \| crc[15:8] \| crc[7:0] \|
okano	0:81b440aaf221	95	* +------+---------+---------+- - - -+---------+-----------+----------+
okano	0:81b440aaf221	96	*/
okano	0:81b440aaf221	97
okano	0:81b440aaf221	98	#include "SDFileSystem.h"
okano	0:81b440aaf221	99
okano	0:81b440aaf221	100	#define SD_COMMAND_TIMEOUT 5000
okano	0:81b440aaf221	101
okano	0:81b440aaf221	102	SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
okano	0:81b440aaf221	103	FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
okano	0:81b440aaf221	104	_cs = 1;
okano	0:81b440aaf221	105	}
okano	0:81b440aaf221	106
okano	0:81b440aaf221	107	int SDFileSystem::disk_initialize() {
okano	0:81b440aaf221	108
okano	0:81b440aaf221	109	_spi.frequency(100000); // Set to 100kHz for initialisation
okano	0:81b440aaf221	110
okano	0:81b440aaf221	111	// Initialise the card by clocking it a bit (cs = 1)
okano	0:81b440aaf221	112	for(int i=0; i<16; i++) {
okano	0:81b440aaf221	113	_spi.write(0xFF);
okano	0:81b440aaf221	114	}
okano	0:81b440aaf221	115
okano	0:81b440aaf221	116	// send CMD0, should return with all zeros except IDLE STATE set (bit 0)
okano	0:81b440aaf221	117	if(_cmd(0, 0) != 0x01) {
okano	0:81b440aaf221	118	fprintf(stderr, "Not in idle state\n");
okano	0:81b440aaf221	119	return 1;
okano	0:81b440aaf221	120	}
okano	0:81b440aaf221	121
okano	0:81b440aaf221	122	// ACMD41 to give host capacity support (repeat until not busy)
okano	0:81b440aaf221	123	// ACMD41 is application specific command, so we send APP_CMD (CMD55) beforehand
okano	0:81b440aaf221	124	for(int i=0;; i++) {
okano	0:81b440aaf221	125	_cmd(55, 0);
okano	0:81b440aaf221	126	int response = _cmd(41, 0);
okano	0:81b440aaf221	127	if(response == 0) {
okano	0:81b440aaf221	128	break;
okano	0:81b440aaf221	129	} else if(i > SD_COMMAND_TIMEOUT) {
okano	0:81b440aaf221	130	fprintf(stderr, "Timeout waiting for card\n");
okano	0:81b440aaf221	131	return 1;
okano	0:81b440aaf221	132	}
okano	0:81b440aaf221	133	}
okano	0:81b440aaf221	134
okano	0:81b440aaf221	135	_sectors = _sd_sectors();
okano	0:81b440aaf221	136
okano	0:81b440aaf221	137	// Set block length to 512 (CMD16)
okano	0:81b440aaf221	138	if(_cmd(16, 512) != 0) {
okano	0:81b440aaf221	139	fprintf(stderr, "Set block timeout\n");
okano	0:81b440aaf221	140	return 1;
okano	0:81b440aaf221	141	}
okano	0:81b440aaf221	142
okano	0:81b440aaf221	143	_spi.frequency(1000000); // Set to 1MHz for data transfer
okano	0:81b440aaf221	144	return 0;
okano	0:81b440aaf221	145	}
okano	0:81b440aaf221	146
okano	0:81b440aaf221	147	int SDFileSystem::disk_write(const char *buffer, int block_number) {
okano	0:81b440aaf221	148	// set write address for single block (CMD24)
okano	0:81b440aaf221	149	if(_cmd(24, block_number * 512) != 0) {
okano	0:81b440aaf221	150	return 1;
okano	0:81b440aaf221	151	}
okano	0:81b440aaf221	152
okano	0:81b440aaf221	153	// send the data block
okano	0:81b440aaf221	154	_write(buffer, 512);
okano	0:81b440aaf221	155	return 0;
okano	0:81b440aaf221	156	}
okano	0:81b440aaf221	157
okano	0:81b440aaf221	158	int SDFileSystem::disk_read(char *buffer, int block_number) {
okano	0:81b440aaf221	159	// set read address for single block (CMD17)
okano	0:81b440aaf221	160	if(_cmd(17, block_number * 512) != 0) {
okano	0:81b440aaf221	161	return 1;
okano	0:81b440aaf221	162	}
okano	0:81b440aaf221	163
okano	0:81b440aaf221	164	// receive the data
okano	0:81b440aaf221	165	_read(buffer, 512);
okano	0:81b440aaf221	166	return 0;
okano	0:81b440aaf221	167	}
okano	0:81b440aaf221	168
okano	0:81b440aaf221	169	int SDFileSystem::disk_status() { return 0; }
okano	0:81b440aaf221	170	int SDFileSystem::disk_sync() { return 0; }
okano	0:81b440aaf221	171	int SDFileSystem::disk_sectors() { return _sectors; }
okano	0:81b440aaf221	172
okano	0:81b440aaf221	173	// PRIVATE FUNCTIONS
okano	0:81b440aaf221	174
okano	0:81b440aaf221	175	int SDFileSystem::_cmd(int cmd, int arg) {
okano	0:81b440aaf221	176	_cs = 0;
okano	0:81b440aaf221	177
okano	0:81b440aaf221	178	// send a command
okano	0:81b440aaf221	179	_spi.write(0x40 \| cmd);
okano	0:81b440aaf221	180	_spi.write(arg >> 24);
okano	0:81b440aaf221	181	_spi.write(arg >> 16);
okano	0:81b440aaf221	182	_spi.write(arg >> 8);
okano	0:81b440aaf221	183	_spi.write(arg >> 0);
okano	0:81b440aaf221	184	_spi.write(0x95);
okano	0:81b440aaf221	185
okano	0:81b440aaf221	186	// wait for the repsonse (response[7] == 0)
okano	0:81b440aaf221	187	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
okano	0:81b440aaf221	188	int response = _spi.write(0xFF);
okano	0:81b440aaf221	189	if(!(response & 0x80)) {
okano	0:81b440aaf221	190	_cs = 1;
okano	0:81b440aaf221	191	return response;
okano	0:81b440aaf221	192	}
okano	0:81b440aaf221	193	}
okano	0:81b440aaf221	194	_cs = 1;
okano	0:81b440aaf221	195	return -1; // timeout
okano	0:81b440aaf221	196	}
okano	0:81b440aaf221	197
okano	0:81b440aaf221	198	int SDFileSystem::_read(char *buffer, int length) {
okano	0:81b440aaf221	199	_cs = 0;
okano	0:81b440aaf221	200
okano	0:81b440aaf221	201	// read until start byte (0xFF)
okano	0:81b440aaf221	202	while(_spi.write(0xFF) != 0xFE);
okano	0:81b440aaf221	203
okano	0:81b440aaf221	204	// read data
okano	0:81b440aaf221	205	for(int i=0; i<length; i++) {
okano	0:81b440aaf221	206	buffer[i] = _spi.write(0xFF);
okano	0:81b440aaf221	207	}
okano	0:81b440aaf221	208	_spi.write(0xFF); // checksum
okano	0:81b440aaf221	209	_spi.write(0xFF);
okano	0:81b440aaf221	210
okano	0:81b440aaf221	211	_cs = 1;
okano	0:81b440aaf221	212	return 0;
okano	0:81b440aaf221	213	}
okano	0:81b440aaf221	214
okano	0:81b440aaf221	215	int SDFileSystem::_write(const char *buffer, int length) {
okano	0:81b440aaf221	216	_cs = 0;
okano	0:81b440aaf221	217
okano	0:81b440aaf221	218	// indicate start of block
okano	0:81b440aaf221	219	_spi.write(0xFE);
okano	0:81b440aaf221	220
okano	0:81b440aaf221	221	// write the data
okano	0:81b440aaf221	222	for(int i=0; i<length; i++) {
okano	0:81b440aaf221	223	_spi.write(buffer[i]);
okano	0:81b440aaf221	224	}
okano	0:81b440aaf221	225
okano	0:81b440aaf221	226	// write the checksum
okano	0:81b440aaf221	227	_spi.write(0xFF);
okano	0:81b440aaf221	228	_spi.write(0xFF);
okano	0:81b440aaf221	229
okano	0:81b440aaf221	230	// check the repsonse token
okano	0:81b440aaf221	231	if((_spi.write(0xFF) & 0x1F) != 0x05) {
okano	0:81b440aaf221	232	_cs = 1;
okano	0:81b440aaf221	233	return 1;
okano	0:81b440aaf221	234	}
okano	0:81b440aaf221	235
okano	0:81b440aaf221	236	// wait for write to finish
okano	0:81b440aaf221	237	while(_spi.write(0xFF) == 0);
okano	0:81b440aaf221	238
okano	0:81b440aaf221	239	_cs = 1;
okano	0:81b440aaf221	240	return 0;
okano	0:81b440aaf221	241	}
okano	0:81b440aaf221	242
okano	0:81b440aaf221	243	static int ext_bits(char *data, int msb, int lsb) {
okano	0:81b440aaf221	244	int bits = 0;
okano	0:81b440aaf221	245	int size = 1 + msb - lsb;
okano	0:81b440aaf221	246	for(int i=0; i<size; i++) {
okano	0:81b440aaf221	247	int position = lsb + i;
okano	0:81b440aaf221	248	int byte = 15 - (position >> 3);
okano	0:81b440aaf221	249	int bit = position & 0x7;
okano	0:81b440aaf221	250	int value = (data[byte] >> bit) & 1;
okano	0:81b440aaf221	251	bits \|= value << i;
okano	0:81b440aaf221	252	}
okano	0:81b440aaf221	253	return bits;
okano	0:81b440aaf221	254	}
okano	0:81b440aaf221	255
okano	0:81b440aaf221	256	int SDFileSystem::_sd_sectors() {
okano	0:81b440aaf221	257
okano	0:81b440aaf221	258	// CMD9, Response R2 (R1 byte + 16-byte block read)
okano	0:81b440aaf221	259	if(_cmd(9, 0) != 0) {
okano	0:81b440aaf221	260	fprintf(stderr, "Didn't get a response from the disk\n");
okano	0:81b440aaf221	261	return 0;
okano	0:81b440aaf221	262	}
okano	0:81b440aaf221	263
okano	0:81b440aaf221	264	char csd[16];
okano	0:81b440aaf221	265	if(_read(csd, 16) != 0) {
okano	0:81b440aaf221	266	fprintf(stderr, "Couldn't read csd response from disk\n");
okano	0:81b440aaf221	267	return 0;
okano	0:81b440aaf221	268	}
okano	0:81b440aaf221	269
okano	0:81b440aaf221	270	// csd_structure : csd[127:126]
okano	0:81b440aaf221	271	// c_size : csd[73:62]
okano	0:81b440aaf221	272	// c_size_mult : csd[49:47]
okano	0:81b440aaf221	273	// read_bl_len : csd[83:80]
okano	0:81b440aaf221	274
okano	0:81b440aaf221	275	int csd_structure = ext_bits(csd, 127, 126);
okano	0:81b440aaf221	276	int c_size = ext_bits(csd, 73, 62);
okano	0:81b440aaf221	277	int c_size_mult = ext_bits(csd, 49, 47);
okano	0:81b440aaf221	278	int read_bl_len = ext_bits(csd, 83, 80);
okano	0:81b440aaf221	279
okano	0:81b440aaf221	280	if(csd_structure != 0) {
okano	0:81b440aaf221	281	fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures");
okano	0:81b440aaf221	282	return 0;
okano	0:81b440aaf221	283	}
okano	0:81b440aaf221	284
okano	0:81b440aaf221	285	int blocks = (c_size + 1) * (1 << (c_size_mult + 2));
okano	0:81b440aaf221	286	int block_size = 1 << read_bl_len;
okano	0:81b440aaf221	287
okano	0:81b440aaf221	288	if(block_size != 512) {
okano	0:81b440aaf221	289	fprintf(stderr, "This disk tastes funny! I only like 512-byte blocks");
okano	0:81b440aaf221	290	return 0;
okano	0:81b440aaf221	291	}
okano	0:81b440aaf221	292
okano	0:81b440aaf221	293	return blocks;
okano	0:81b440aaf221	294	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	21 Sep 2010
Imports:	34
Forks:	0
Commits:	2
Dependents:	0
Dependencies:	1
Followers:	2
Issues:	0

SDFileSystem.cpp@1:1a76280274de, 2010-09-22 (annotated)

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