/* SDEXT emulation currently excepts the cartridge area (segments 4-7) to be filled
* with the FLASH ROM content. Even segment 7, which will be copied to the second 64K "hidden"
* and pagable flash area of the SD cartridge. Currently, there is no support for the full
* sized SDEXT flash image */
void sdext_init ( void )
{
/* try to detect SDEXT ROM extension and only turn on emulation if it exists */
if (sdext_detect_rom()) {
WARNING_WINDOW("No SD-card cartridge ROM code found in loaded ROM set. SD card hardware emulation has been disabled!");
*sdimg_path = 0;
sdf = NULL;
SD_DEBUG("SDEXT: init: REFUSE: no SD-card cartridge ROM code found in loaded ROM set." NL);
return;
}
SD_DEBUG("SDEXT: init: cool, SD-card cartridge ROM code seems to be found in loaded ROM set, enabling SD card hardware emulation ..." NL);
sdf = open_emu_file(config_getopt_str("sdimg"), "rb", sdimg_path); // open in read-only mode, to get the path
if (sdf) {
fclose(sdf);
sdf = fopen(sdimg_path, "r+b");
if (sdf) {
DEBUGPRINT("SDEXT: SD image file is re-open in read/write mode, good (fd=%d)." NL, fileno(sdf));
} else {
sdf = fopen(sdimg_path, "rb");
DEBUGPRINT("SDEXT: SD image cannot be re-open in read-write mode, using read-only access (fd=%d)." NL, fileno(sdf));
}
}
if (!sdf) {
WARNING_WINDOW("SD card image file \"%s\" cannot be open: %s. You can use Xep128 but SD card access won't work!", sdimg_path, ERRSTR());
*sdimg_path = 0;
} else {
sdfd = fileno(sdf);
sd_card_size = lseek(sdfd, 0, SEEK_END);
SD_DEBUG("SDEXT: SD card size is: %ld bytes" NL, sd_card_size);
if (sd_card_size > MAX_CARD_SIZE || sd_card_size < MIN_CARD_SIZE) {
fclose(sdf);
sdf = NULL;
ERROR_WINDOW("SD card image file \"%s\" is too small or large, valid range is %ld - %ld Mbytes, but this one is %ld bytes long (about %ld Mbytes). SD access has been disabled!",
sdimg_path, MIN_CARD_SIZE >> 20, MAX_CARD_SIZE >> 20,
sd_card_size, sd_card_size >> 20
);
*sdimg_path = 0;
}
}
/**
* \ingroup sd_raw
* Initializes memory card communication.
*
* \returns 0 on failure, 1 on success.
*/
uint8_t sd_raw_init(void)
{
_sd_infodirty = 1;
/* enable inputs for reading card status */
configure_pin_available();
configure_pin_locked();
/* enable outputs for MOSI, SCK, SS, input for MISO */
configure_pin_mosi();
configure_pin_sck();
configure_pin_ss();
configure_pin_miso();
unselect_card();
/* initialize SPI with lowest frequency; max. 400kHz during identification mode of card */
SPCR = (0 << SPIE) | /* SPI Interrupt Enable */
(1 << SPE) | /* SPI Enable */
(0 << DORD) | /* Data Order: MSB first */
(1 << MSTR) | /* Master mode */
(0 << CPOL) | /* Clock Polarity: SCK low when idle */
(0 << CPHA) | /* Clock Phase: sample on rising SCK edge */
(1 << SPR1) | /* Clock Frequency: f_OSC / 128 */
(1 << SPR0);
SPSR &= ~(1 << SPI2X); /* No doubled clock frequency */
/* initialization procedure */
sd_raw_card_type = 0;
if(!sd_raw_available())
{
SD_DEBUG("SD card not available");
return 0;
}
/* card needs 74 cycles minimum to start up */
uint16_t i;
for(i = 0; i < 10; ++i)
{
/* wait 8 clock cycles */
sd_raw_rec_byte();
}
/* address card */
select_card();
/* reset card */
uint8_t response;
for(i = 0; ; ++i)
{
response = sd_raw_send_command(CMD_GO_IDLE_STATE, 0);
if(response == (1 << R1_IDLE_STATE))
break;
if(i == 0x1ff)
{
unselect_card();
SD_DEBUG("Some kind of error.");
return 0;
}
}
#if SD_RAW_SDHC
/* check for version of SD card specification */
response = sd_raw_send_command(CMD_SEND_IF_COND, 0x100 /* 2.7V - 3.6V */ | 0xaa /* test pattern */);
if((response & (1 << R1_ILL_COMMAND)) == 0)
{
sd_raw_rec_byte();
sd_raw_rec_byte();
if((sd_raw_rec_byte() & 0x01) == 0)
{
SD_DEBUG("Bad voltage");
return 0; /* card operation voltage range doesn't match */
}
if(sd_raw_rec_byte() != 0xaa)
{
SD_DEBUG("Bad test pattern.");
return 0; /* wrong test pattern */
}
/* card conforms to SD 2 card specification */
sd_raw_card_type |= (1 << SD_RAW_SPEC_2);
}
else
#endif
{
/* determine SD/MMC card type */
sd_raw_send_command(CMD_APP, 0);
response = sd_raw_send_command(CMD_SD_SEND_OP_COND, 0);
if((response & (1 << R1_ILL_COMMAND)) == 0)
{
/* card conforms to SD 1 card specification */
sd_raw_card_type |= (1 << SD_RAW_SPEC_1);
}
else
{
/* MMC card */
}
}
/* wait for card to get ready */
for(i = 0; ; ++i)
{
if(sd_raw_card_type & ((1 << SD_RAW_SPEC_1) | (1 << SD_RAW_SPEC_2)))
{
uint32_t arg = 0;
#if SD_RAW_SDHC
if(sd_raw_card_type & (1 << SD_RAW_SPEC_2))
arg = 0x40000000;
#endif
sd_raw_send_command(CMD_APP, 0);
response = sd_raw_send_command(CMD_SD_SEND_OP_COND, arg);
}
else
{
response = sd_raw_send_command(CMD_SEND_OP_COND, 0);
}
if((response & (1 << R1_IDLE_STATE)) == 0)
break;
if(i == 0x7fff)
{
unselect_card();
SD_DEBUG("Some kind of error.");
return 0;
}
}
#if SD_RAW_SDHC
if(sd_raw_card_type & (1 << SD_RAW_SPEC_2))
{
if(sd_raw_send_command(CMD_READ_OCR, 0))
{
unselect_card();
SD_DEBUG("Some kind of error.");
return 0;
}
if(sd_raw_rec_byte() & 0x40)
sd_raw_card_type |= (1 << SD_RAW_SPEC_SDHC);
sd_raw_rec_byte();
sd_raw_rec_byte();
sd_raw_rec_byte();
}
#endif
/* set block size to 512 bytes */
if(sd_raw_send_command(CMD_SET_BLOCKLEN, 512))
{
unselect_card();
SD_DEBUG("Some kind of error.");
return 0;
}
/* deaddress card */
unselect_card();
/* switch to highest SPI frequency possible */
SPCR &= ~((1 << SPR1) | (1 << SPR0)); /* Clock Frequency: f_OSC / 4 */
SPSR |= (1 << SPI2X); /* Doubled Clock Frequency: f_OSC / 2 */
#if !SD_RAW_SAVE_RAM
/* the first block is likely to be accessed first, so precache it here */
raw_block_address = (unsigned long) -1;
#if SD_RAW_WRITE_BUFFERING
raw_block_written = 1;
#endif
if(!sd_raw_read(0, raw_block, sizeof(raw_block)))
{
SD_DEBUG("Some kind of error.");
return 0;
}
#endif
return 1;
}
