camera_online_server - this will take a image from C328 serial camera an…

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Mitesh Patel / Mbed 2 deprecated camera_online_server

this will take a image from C328 serial camera and store those images in mbed flash as html and this html page is uploaded into the server at ip:192.168.1.2

Dependencies: mbed

SDFileSystem.cpp@0:e1a0471e5ffb, 2010-12-15 (annotated)

Committer:: mitesh2patel
Date:: Wed Dec 15 15:01:56 2010 +0000
Revision:: 0:e1a0471e5ffb

Who changed what in which revision?

User	Revision	Line number	New contents of line
mitesh2patel	0:e1a0471e5ffb	1	/* mbed Microcontroller Library - SDFileSystem
mitesh2patel	0:e1a0471e5ffb	2	* Copyright (c) 2008-2009, sford
mitesh2patel	0:e1a0471e5ffb	3	*
mitesh2patel	0:e1a0471e5ffb	4	* Introduction
mitesh2patel	0:e1a0471e5ffb	5	* ------------
mitesh2patel	0:e1a0471e5ffb	6	* SD and MMC cards support a number of interfaces, but common to them all
mitesh2patel	0:e1a0471e5ffb	7	* is one based on SPI. This is the one I'm implmenting because it means
mitesh2patel	0:e1a0471e5ffb	8	* it is much more portable even though not so performant, and we already
mitesh2patel	0:e1a0471e5ffb	9	* have the mbed SPI Interface!
mitesh2patel	0:e1a0471e5ffb	10	*
mitesh2patel	0:e1a0471e5ffb	11	* The main reference I'm using is Chapter 7, "SPI Mode" of:
mitesh2patel	0:e1a0471e5ffb	12	* http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
mitesh2patel	0:e1a0471e5ffb	13	*
mitesh2patel	0:e1a0471e5ffb	14	* SPI Startup
mitesh2patel	0:e1a0471e5ffb	15	* -----------
mitesh2patel	0:e1a0471e5ffb	16	* The SD card powers up in SD mode. The SPI interface mode is selected by
mitesh2patel	0:e1a0471e5ffb	17	* asserting CS low and sending the reset command (CMD0). The card will
mitesh2patel	0:e1a0471e5ffb	18	* respond with a (R1) response.
mitesh2patel	0:e1a0471e5ffb	19	*
mitesh2patel	0:e1a0471e5ffb	20	* CMD8 is optionally sent to determine the voltage range supported, and
mitesh2patel	0:e1a0471e5ffb	21	* indirectly determine whether it is a version 1.x SD/non-SD card or
mitesh2patel	0:e1a0471e5ffb	22	* version 2.x. I'll just ignore this for now.
mitesh2patel	0:e1a0471e5ffb	23	*
mitesh2patel	0:e1a0471e5ffb	24	* ACMD41 is repeatedly issued to initialise the card, until "in idle"
mitesh2patel	0:e1a0471e5ffb	25	* (bit 0) of the R1 response goes to '0', indicating it is initialised.
mitesh2patel	0:e1a0471e5ffb	26	*
mitesh2patel	0:e1a0471e5ffb	27	* You should also indicate whether the host supports High Capicity cards,
mitesh2patel	0:e1a0471e5ffb	28	* and check whether the card is high capacity - i'll also ignore this
mitesh2patel	0:e1a0471e5ffb	29	*
mitesh2patel	0:e1a0471e5ffb	30	* SPI Protocol
mitesh2patel	0:e1a0471e5ffb	31	* ------------
mitesh2patel	0:e1a0471e5ffb	32	* The SD SPI protocol is based on transactions made up of 8-bit words, with
mitesh2patel	0:e1a0471e5ffb	33	* the host starting every bus transaction by asserting the CS signal low. The
mitesh2patel	0:e1a0471e5ffb	34	* card always responds to commands, data blocks and errors.
mitesh2patel	0:e1a0471e5ffb	35	*
mitesh2patel	0:e1a0471e5ffb	36	* The protocol supports a CRC, but by default it is off (except for the
mitesh2patel	0:e1a0471e5ffb	37	* first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
mitesh2patel	0:e1a0471e5ffb	38	* I'll leave the CRC off I think!
mitesh2patel	0:e1a0471e5ffb	39	*
mitesh2patel	0:e1a0471e5ffb	40	* Standard capacity cards have variable data block sizes, whereas High
mitesh2patel	0:e1a0471e5ffb	41	* Capacity cards fix the size of data block to 512 bytes. I'll therefore
mitesh2patel	0:e1a0471e5ffb	42	* just always use the Standard Capacity cards with a block size of 512 bytes.
mitesh2patel	0:e1a0471e5ffb	43	* This is set with CMD16.
mitesh2patel	0:e1a0471e5ffb	44	*
mitesh2patel	0:e1a0471e5ffb	45	* You can read and write single blocks (CMD17, CMD25) or multiple blocks
mitesh2patel	0:e1a0471e5ffb	46	* (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
mitesh2patel	0:e1a0471e5ffb	47	* the card gets a read command, it responds with a response token, and then
mitesh2patel	0:e1a0471e5ffb	48	* a data token or an error.
mitesh2patel	0:e1a0471e5ffb	49	*
mitesh2patel	0:e1a0471e5ffb	50	* SPI Command Format
mitesh2patel	0:e1a0471e5ffb	51	* ------------------
mitesh2patel	0:e1a0471e5ffb	52	* Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
mitesh2patel	0:e1a0471e5ffb	53	*
mitesh2patel	0:e1a0471e5ffb	54	* +---------------+------------+------------+-----------+----------+--------------+
mitesh2patel	0:e1a0471e5ffb	55	* \| 01 \| cmd[5:0] \| arg[31:24] \| arg[23:16] \| arg[15:8] \| arg[7:0] \| crc[6:0] \| 1 \|
mitesh2patel	0:e1a0471e5ffb	56	* +---------------+------------+------------+-----------+----------+--------------+
mitesh2patel	0:e1a0471e5ffb	57	*
mitesh2patel	0:e1a0471e5ffb	58	* As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
mitesh2patel	0:e1a0471e5ffb	59	*
mitesh2patel	0:e1a0471e5ffb	60	* All Application Specific commands shall be preceded with APP_CMD (CMD55).
mitesh2patel	0:e1a0471e5ffb	61	*
mitesh2patel	0:e1a0471e5ffb	62	* SPI Response Format
mitesh2patel	0:e1a0471e5ffb	63	* -------------------
mitesh2patel	0:e1a0471e5ffb	64	* The main response format (R1) is a status byte (normally zero). Key flags:
mitesh2patel	0:e1a0471e5ffb	65	* idle - 1 if the card is in an idle state/initialising
mitesh2patel	0:e1a0471e5ffb	66	* cmd - 1 if an illegal command code was detected
mitesh2patel	0:e1a0471e5ffb	67	*
mitesh2patel	0:e1a0471e5ffb	68	* +-------------------------------------------------+
mitesh2patel	0:e1a0471e5ffb	69	* R1 \| 0 \| arg \| addr \| seq \| crc \| cmd \| erase \| idle \|
mitesh2patel	0:e1a0471e5ffb	70	* +-------------------------------------------------+
mitesh2patel	0:e1a0471e5ffb	71	*
mitesh2patel	0:e1a0471e5ffb	72	* R1b is the same, except it is followed by a busy signal (zeros) until
mitesh2patel	0:e1a0471e5ffb	73	* the first non-zero byte when it is ready again.
mitesh2patel	0:e1a0471e5ffb	74	*
mitesh2patel	0:e1a0471e5ffb	75	* Data Response Token
mitesh2patel	0:e1a0471e5ffb	76	* -------------------
mitesh2patel	0:e1a0471e5ffb	77	* Every data block written to the card is acknowledged by a byte
mitesh2patel	0:e1a0471e5ffb	78	* response token
mitesh2patel	0:e1a0471e5ffb	79	*
mitesh2patel	0:e1a0471e5ffb	80	* +----------------------+
mitesh2patel	0:e1a0471e5ffb	81	* \| xxx \| 0 \| status \| 1 \|
mitesh2patel	0:e1a0471e5ffb	82	* +----------------------+
mitesh2patel	0:e1a0471e5ffb	83	* 010 - OK!
mitesh2patel	0:e1a0471e5ffb	84	* 101 - CRC Error
mitesh2patel	0:e1a0471e5ffb	85	* 110 - Write Error
mitesh2patel	0:e1a0471e5ffb	86	*
mitesh2patel	0:e1a0471e5ffb	87	* Single Block Read and Write
mitesh2patel	0:e1a0471e5ffb	88	* ---------------------------
mitesh2patel	0:e1a0471e5ffb	89	*
mitesh2patel	0:e1a0471e5ffb	90	* Block transfers have a byte header, followed by the data, followed
mitesh2patel	0:e1a0471e5ffb	91	* by a 16-bit CRC. In our case, the data will always be 512 bytes.
mitesh2patel	0:e1a0471e5ffb	92	*
mitesh2patel	0:e1a0471e5ffb	93	* +------+---------+---------+- - - -+---------+-----------+----------+
mitesh2patel	0:e1a0471e5ffb	94	* \| 0xFE \| data[0] \| data[1] \| \| data[n] \| crc[15:8] \| crc[7:0] \|
mitesh2patel	0:e1a0471e5ffb	95	* +------+---------+---------+- - - -+---------+-----------+----------+
mitesh2patel	0:e1a0471e5ffb	96	*/
mitesh2patel	0:e1a0471e5ffb	97
mitesh2patel	0:e1a0471e5ffb	98	#include "SDFileSystem.h"
mitesh2patel	0:e1a0471e5ffb	99
mitesh2patel	0:e1a0471e5ffb	100	#define SD_COMMAND_TIMEOUT 5000
mitesh2patel	0:e1a0471e5ffb	101
mitesh2patel	0:e1a0471e5ffb	102	//#define CR "\n"
mitesh2patel	0:e1a0471e5ffb	103	#define CR "\r\n"
mitesh2patel	0:e1a0471e5ffb	104
mitesh2patel	0:e1a0471e5ffb	105	SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
mitesh2patel	0:e1a0471e5ffb	106	FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs) {
mitesh2patel	0:e1a0471e5ffb	107	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	108	}
mitesh2patel	0:e1a0471e5ffb	109
mitesh2patel	0:e1a0471e5ffb	110	#define R1_IDLE_STATE (1 << 0)
mitesh2patel	0:e1a0471e5ffb	111	#define R1_ERASE_RESET (1 << 1)
mitesh2patel	0:e1a0471e5ffb	112	#define R1_ILLEGAL_COMMAND (1 << 2)
mitesh2patel	0:e1a0471e5ffb	113	#define R1_COM_CRC_ERROR (1 << 3)
mitesh2patel	0:e1a0471e5ffb	114	#define R1_ERASE_SEQUENCE_ERROR (1 << 4)
mitesh2patel	0:e1a0471e5ffb	115	#define R1_ADDRESS_ERROR (1 << 5)
mitesh2patel	0:e1a0471e5ffb	116	#define R1_PARAMETER_ERROR (1 << 6)
mitesh2patel	0:e1a0471e5ffb	117
mitesh2patel	0:e1a0471e5ffb	118	int SDFileSystem::disk_initialize() {
mitesh2patel	0:e1a0471e5ffb	119
mitesh2patel	0:e1a0471e5ffb	120	_spi.frequency(100000); // Set to 100kHz for initialisation
mitesh2patel	0:e1a0471e5ffb	121
mitesh2patel	0:e1a0471e5ffb	122	// Initialise the card by clocking it a bit (cs = 1)
mitesh2patel	0:e1a0471e5ffb	123	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	124	for(int i=0; i<16; i++) {
mitesh2patel	0:e1a0471e5ffb	125	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	126	}
mitesh2patel	0:e1a0471e5ffb	127
mitesh2patel	0:e1a0471e5ffb	128	// send CMD0, should return with all zeros except IDLE STATE set (bit 0)
mitesh2patel	0:e1a0471e5ffb	129	if(_cmd(0, 0) != R1_IDLE_STATE) {
mitesh2patel	0:e1a0471e5ffb	130	fprintf(stderr, "No disk, or could not put SD card into SPI idle state" CR);
mitesh2patel	0:e1a0471e5ffb	131	return 1;
mitesh2patel	0:e1a0471e5ffb	132	}
mitesh2patel	0:e1a0471e5ffb	133
mitesh2patel	0:e1a0471e5ffb	134	int r = _cmd8();
mitesh2patel	0:e1a0471e5ffb	135	if(r == R1_IDLE_STATE) {
mitesh2patel	0:e1a0471e5ffb	136	printf("SD version 2.x" CR);
mitesh2patel	0:e1a0471e5ffb	137	} else if(r == (R1_IDLE_STATE \| R1_ILLEGAL_COMMAND)) {
mitesh2patel	0:e1a0471e5ffb	138	printf("SD version 1.x" CR);
mitesh2patel	0:e1a0471e5ffb	139	} else {
mitesh2patel	0:e1a0471e5ffb	140	error("Unknown SD version" CR);
mitesh2patel	0:e1a0471e5ffb	141	}
mitesh2patel	0:e1a0471e5ffb	142
mitesh2patel	0:e1a0471e5ffb	143	// ACMD41 to give host capacity support (repeat until not busy)
mitesh2patel	0:e1a0471e5ffb	144	// ACMD41 is application specific command, so we send APP_CMD (CMD55) beforehand
mitesh2patel	0:e1a0471e5ffb	145	for(int i=0;; i++) {
mitesh2patel	0:e1a0471e5ffb	146	_cmd(55, 0);
mitesh2patel	0:e1a0471e5ffb	147	int response = _cmd(41, 0);
mitesh2patel	0:e1a0471e5ffb	148	if(response == 0) {
mitesh2patel	0:e1a0471e5ffb	149	break;
mitesh2patel	0:e1a0471e5ffb	150	} else if(i > SD_COMMAND_TIMEOUT) {
mitesh2patel	0:e1a0471e5ffb	151	fprintf(stderr, "Timeout waiting for card" CR);
mitesh2patel	0:e1a0471e5ffb	152	return 1;
mitesh2patel	0:e1a0471e5ffb	153	}
mitesh2patel	0:e1a0471e5ffb	154	}
mitesh2patel	0:e1a0471e5ffb	155
mitesh2patel	0:e1a0471e5ffb	156	// printf("OK" CR);
mitesh2patel	0:e1a0471e5ffb	157
mitesh2patel	0:e1a0471e5ffb	158	_sectors = _sd_sectors();
mitesh2patel	0:e1a0471e5ffb	159
mitesh2patel	0:e1a0471e5ffb	160	// Set block length to 512 (CMD16)
mitesh2patel	0:e1a0471e5ffb	161	if(_cmd(16, 512) != 0) {
mitesh2patel	0:e1a0471e5ffb	162	fprintf(stderr, "Set block timeout" CR);
mitesh2patel	0:e1a0471e5ffb	163	return 1;
mitesh2patel	0:e1a0471e5ffb	164	}
mitesh2patel	0:e1a0471e5ffb	165
mitesh2patel	0:e1a0471e5ffb	166	_spi.frequency(1000000); // Set to 1MHz for data transfer
mitesh2patel	0:e1a0471e5ffb	167	return 0;
mitesh2patel	0:e1a0471e5ffb	168	}
mitesh2patel	0:e1a0471e5ffb	169
mitesh2patel	0:e1a0471e5ffb	170	int SDFileSystem::disk_write(const char *buffer, int block_number) {
mitesh2patel	0:e1a0471e5ffb	171	// set write address for single block (CMD24)
mitesh2patel	0:e1a0471e5ffb	172	if(_cmd(24, block_number * 512) != 0) {
mitesh2patel	0:e1a0471e5ffb	173	return 1;
mitesh2patel	0:e1a0471e5ffb	174	}
mitesh2patel	0:e1a0471e5ffb	175
mitesh2patel	0:e1a0471e5ffb	176	// send the data block
mitesh2patel	0:e1a0471e5ffb	177	_write(buffer, 512);
mitesh2patel	0:e1a0471e5ffb	178	return 0;
mitesh2patel	0:e1a0471e5ffb	179	}
mitesh2patel	0:e1a0471e5ffb	180
mitesh2patel	0:e1a0471e5ffb	181	int SDFileSystem::disk_read(char *buffer, int block_number) {
mitesh2patel	0:e1a0471e5ffb	182	// set read address for single block (CMD17)
mitesh2patel	0:e1a0471e5ffb	183	if(_cmd(17, block_number * 512) != 0) {
mitesh2patel	0:e1a0471e5ffb	184	return 1;
mitesh2patel	0:e1a0471e5ffb	185	}
mitesh2patel	0:e1a0471e5ffb	186
mitesh2patel	0:e1a0471e5ffb	187	// receive the data
mitesh2patel	0:e1a0471e5ffb	188	_read(buffer, 512);
mitesh2patel	0:e1a0471e5ffb	189	return 0;
mitesh2patel	0:e1a0471e5ffb	190	}
mitesh2patel	0:e1a0471e5ffb	191
mitesh2patel	0:e1a0471e5ffb	192	int SDFileSystem::disk_status() { return 0; }
mitesh2patel	0:e1a0471e5ffb	193	int SDFileSystem::disk_sync() { return 0; }
mitesh2patel	0:e1a0471e5ffb	194	int SDFileSystem::disk_sectors() { return _sectors; }
mitesh2patel	0:e1a0471e5ffb	195
mitesh2patel	0:e1a0471e5ffb	196	// PRIVATE FUNCTIONS
mitesh2patel	0:e1a0471e5ffb	197
mitesh2patel	0:e1a0471e5ffb	198	int SDFileSystem::_cmd(int cmd, int arg) {
mitesh2patel	0:e1a0471e5ffb	199	_cs = 0;
mitesh2patel	0:e1a0471e5ffb	200
mitesh2patel	0:e1a0471e5ffb	201	// send a command
mitesh2patel	0:e1a0471e5ffb	202	_spi.write(0x40 \| cmd);
mitesh2patel	0:e1a0471e5ffb	203	_spi.write(arg >> 24);
mitesh2patel	0:e1a0471e5ffb	204	_spi.write(arg >> 16);
mitesh2patel	0:e1a0471e5ffb	205	_spi.write(arg >> 8);
mitesh2patel	0:e1a0471e5ffb	206	_spi.write(arg >> 0);
mitesh2patel	0:e1a0471e5ffb	207	_spi.write(0x95);
mitesh2patel	0:e1a0471e5ffb	208
mitesh2patel	0:e1a0471e5ffb	209	// wait for the repsonse (response[7] == 0)
mitesh2patel	0:e1a0471e5ffb	210	for(int i=0; i<SD_COMMAND_TIMEOUT; i++) {
mitesh2patel	0:e1a0471e5ffb	211	int response = _spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	212	if(!(response & 0x80)) {
mitesh2patel	0:e1a0471e5ffb	213	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	214	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	215	return response;
mitesh2patel	0:e1a0471e5ffb	216	}
mitesh2patel	0:e1a0471e5ffb	217	}
mitesh2patel	0:e1a0471e5ffb	218	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	219	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	220	return -1; // timeout
mitesh2patel	0:e1a0471e5ffb	221	}
mitesh2patel	0:e1a0471e5ffb	222
mitesh2patel	0:e1a0471e5ffb	223	int SDFileSystem::_cmd8() {
mitesh2patel	0:e1a0471e5ffb	224	_cs = 0;
mitesh2patel	0:e1a0471e5ffb	225
mitesh2patel	0:e1a0471e5ffb	226	// send a command
mitesh2patel	0:e1a0471e5ffb	227	_spi.write(0x40 \| 8); // CMD8
mitesh2patel	0:e1a0471e5ffb	228	_spi.write(0x00); // reserved
mitesh2patel	0:e1a0471e5ffb	229	_spi.write(0x00); // reserved
mitesh2patel	0:e1a0471e5ffb	230	_spi.write(0x01); // 3.3v
mitesh2patel	0:e1a0471e5ffb	231	_spi.write(0xAA); // check pattern
mitesh2patel	0:e1a0471e5ffb	232	_spi.write(0x87); // crc
mitesh2patel	0:e1a0471e5ffb	233
mitesh2patel	0:e1a0471e5ffb	234	// wait for the repsonse (response[7] == 0)
mitesh2patel	0:e1a0471e5ffb	235	for(int i=0; i<SD_COMMAND_TIMEOUT * 1000; i++) {
mitesh2patel	0:e1a0471e5ffb	236	char response[5];
mitesh2patel	0:e1a0471e5ffb	237	response[0] = _spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	238	if(!(response[0] & 0x80)) {
mitesh2patel	0:e1a0471e5ffb	239	for(int j=1; j<5; j++) {
mitesh2patel	0:e1a0471e5ffb	240	response[i] = _spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	241	}
mitesh2patel	0:e1a0471e5ffb	242	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	243	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	244	return response[0];
mitesh2patel	0:e1a0471e5ffb	245	}
mitesh2patel	0:e1a0471e5ffb	246	}
mitesh2patel	0:e1a0471e5ffb	247	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	248	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	249	return -1; // timeout
mitesh2patel	0:e1a0471e5ffb	250	}
mitesh2patel	0:e1a0471e5ffb	251
mitesh2patel	0:e1a0471e5ffb	252	int SDFileSystem::_read(char *buffer, int length) {
mitesh2patel	0:e1a0471e5ffb	253	_cs = 0;
mitesh2patel	0:e1a0471e5ffb	254
mitesh2patel	0:e1a0471e5ffb	255	// read until start byte (0xFF)
mitesh2patel	0:e1a0471e5ffb	256	while(_spi.write(0xFF) != 0xFE);
mitesh2patel	0:e1a0471e5ffb	257
mitesh2patel	0:e1a0471e5ffb	258	// read data
mitesh2patel	0:e1a0471e5ffb	259	for(int i=0; i<length; i++) {
mitesh2patel	0:e1a0471e5ffb	260	buffer[i] = _spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	261	}
mitesh2patel	0:e1a0471e5ffb	262	_spi.write(0xFF); // checksum
mitesh2patel	0:e1a0471e5ffb	263	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	264
mitesh2patel	0:e1a0471e5ffb	265	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	266	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	267	return 0;
mitesh2patel	0:e1a0471e5ffb	268	}
mitesh2patel	0:e1a0471e5ffb	269
mitesh2patel	0:e1a0471e5ffb	270	int SDFileSystem::_write(const char *buffer, int length) {
mitesh2patel	0:e1a0471e5ffb	271	_cs = 0;
mitesh2patel	0:e1a0471e5ffb	272
mitesh2patel	0:e1a0471e5ffb	273	// indicate start of block
mitesh2patel	0:e1a0471e5ffb	274	_spi.write(0xFE);
mitesh2patel	0:e1a0471e5ffb	275
mitesh2patel	0:e1a0471e5ffb	276	// write the data
mitesh2patel	0:e1a0471e5ffb	277	for(int i=0; i<length; i++) {
mitesh2patel	0:e1a0471e5ffb	278	_spi.write(buffer[i]);
mitesh2patel	0:e1a0471e5ffb	279	}
mitesh2patel	0:e1a0471e5ffb	280
mitesh2patel	0:e1a0471e5ffb	281	// write the checksum
mitesh2patel	0:e1a0471e5ffb	282	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	283	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	284
mitesh2patel	0:e1a0471e5ffb	285	// check the repsonse token
mitesh2patel	0:e1a0471e5ffb	286	if((_spi.write(0xFF) & 0x1F) != 0x05) {
mitesh2patel	0:e1a0471e5ffb	287	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	288	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	289	return 1;
mitesh2patel	0:e1a0471e5ffb	290	}
mitesh2patel	0:e1a0471e5ffb	291
mitesh2patel	0:e1a0471e5ffb	292	// wait for write to finish
mitesh2patel	0:e1a0471e5ffb	293	while(_spi.write(0xFF) == 0);
mitesh2patel	0:e1a0471e5ffb	294
mitesh2patel	0:e1a0471e5ffb	295	_cs = 1;
mitesh2patel	0:e1a0471e5ffb	296	_spi.write(0xFF);
mitesh2patel	0:e1a0471e5ffb	297	return 0;
mitesh2patel	0:e1a0471e5ffb	298	}
mitesh2patel	0:e1a0471e5ffb	299
mitesh2patel	0:e1a0471e5ffb	300	static int ext_bits(char *data, int msb, int lsb) {
mitesh2patel	0:e1a0471e5ffb	301	int bits = 0;
mitesh2patel	0:e1a0471e5ffb	302	int size = 1 + msb - lsb;
mitesh2patel	0:e1a0471e5ffb	303	for(int i=0; i<size; i++) {
mitesh2patel	0:e1a0471e5ffb	304	int position = lsb + i;
mitesh2patel	0:e1a0471e5ffb	305	int byte = 15 - (position >> 3);
mitesh2patel	0:e1a0471e5ffb	306	int bit = position & 0x7;
mitesh2patel	0:e1a0471e5ffb	307	int value = (data[byte] >> bit) & 1;
mitesh2patel	0:e1a0471e5ffb	308	bits \|= value << i;
mitesh2patel	0:e1a0471e5ffb	309	}
mitesh2patel	0:e1a0471e5ffb	310	return bits;
mitesh2patel	0:e1a0471e5ffb	311	}
mitesh2patel	0:e1a0471e5ffb	312
mitesh2patel	0:e1a0471e5ffb	313	int SDFileSystem::_sd_sectors() {
mitesh2patel	0:e1a0471e5ffb	314
mitesh2patel	0:e1a0471e5ffb	315	// CMD9, Response R2 (R1 byte + 16-byte block read)
mitesh2patel	0:e1a0471e5ffb	316	if(_cmd(9, 0) != 0) {
mitesh2patel	0:e1a0471e5ffb	317	fprintf(stderr, "Didn't get a response from the disk" CR);
mitesh2patel	0:e1a0471e5ffb	318	return 0;
mitesh2patel	0:e1a0471e5ffb	319	}
mitesh2patel	0:e1a0471e5ffb	320
mitesh2patel	0:e1a0471e5ffb	321	char csd[16];
mitesh2patel	0:e1a0471e5ffb	322	if(_read(csd, 16) != 0) {
mitesh2patel	0:e1a0471e5ffb	323	fprintf(stderr, "Couldn't read csd response from disk" CR);
mitesh2patel	0:e1a0471e5ffb	324	return 0;
mitesh2patel	0:e1a0471e5ffb	325	}
mitesh2patel	0:e1a0471e5ffb	326
mitesh2patel	0:e1a0471e5ffb	327	// csd_structure : csd[127:126]
mitesh2patel	0:e1a0471e5ffb	328	// c_size : csd[73:62]
mitesh2patel	0:e1a0471e5ffb	329	// c_size_mult : csd[49:47]
mitesh2patel	0:e1a0471e5ffb	330	// read_bl_len : csd[83:80]
mitesh2patel	0:e1a0471e5ffb	331
mitesh2patel	0:e1a0471e5ffb	332	int csd_structure = ext_bits(csd, 127, 126);
mitesh2patel	0:e1a0471e5ffb	333	int c_size = ext_bits(csd, 73, 62);
mitesh2patel	0:e1a0471e5ffb	334	int c_size_mult = ext_bits(csd, 49, 47);
mitesh2patel	0:e1a0471e5ffb	335	int read_bl_len = ext_bits(csd, 83, 80);
mitesh2patel	0:e1a0471e5ffb	336
mitesh2patel	0:e1a0471e5ffb	337	if(csd_structure != 0) {
mitesh2patel	0:e1a0471e5ffb	338	fprintf(stderr, "This disk tastes funny! I only know about type 0 CSD structures" CR);
mitesh2patel	0:e1a0471e5ffb	339	// Non-zero is SDHC.
mitesh2patel	0:e1a0471e5ffb	340	return 0;
mitesh2patel	0:e1a0471e5ffb	341	}
mitesh2patel	0:e1a0471e5ffb	342
mitesh2patel	0:e1a0471e5ffb	343	int blocks = (c_size + 1) * (1 << (c_size_mult + 2));
mitesh2patel	0:e1a0471e5ffb	344	int block_size = 1 << read_bl_len;
mitesh2patel	0:e1a0471e5ffb	345
mitesh2patel	0:e1a0471e5ffb	346	if (block_size != 512 && block_size != 1024) {
mitesh2patel	0:e1a0471e5ffb	347	fprintf(stderr, "This disk tastes funny! %d byte block. I only like 512 or 1024 -byte blocks" CR, block_size);
mitesh2patel	0:e1a0471e5ffb	348	return 0;
mitesh2patel	0:e1a0471e5ffb	349	}
mitesh2patel	0:e1a0471e5ffb	350
mitesh2patel	0:e1a0471e5ffb	351	return blocks;
mitesh2patel	0:e1a0471e5ffb	352	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	15 Dec 2010
Imports:	21
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	2

SDFileSystem.cpp@0:e1a0471e5ffb, 2010-12-15 (annotated)

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