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Rewrite readblock in assembly

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This commit is contained in:
Byron Lathi
2023-08-08 19:28:10 -07:00
parent 446f4e7539
commit e73c4e1d08
7 changed files with 606 additions and 560 deletions
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82
sw/bios/devices/sd_card.c
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@@ -276,56 +276,58 @@ void SD_sendStatus(uint8_t *res)
token = 0x0X - Data error
token = 0xFF - timeout
*******************************************************************************/
uint8_t SD_readSingleBlock(uint32_t addr, uint8_t *buf, uint8_t *token)
{
uint8_t res1, read;
uint16_t readAttempts;
uint16_t i;
// uint8_t SD_readSingleBlock(uint32_t addr, uint8_t *buf, uint8_t *token)
// {
// uint8_t res1, read;
// uint16_t readAttempts;
// uint16_t i;
// set token to none
*token = 0xFF;
// // set token to none
// *token = 0xFF;
// assert chip select
spi_exchange(0xFF);
spi_select(0);
spi_exchange(0xFF);
// // assert chip select
// spi_exchange(0xFF);
// spi_select(0);
// spi_exchange(0xFF);
// send CMD17
SD_command(CMD17, addr, CMD17_CRC);
// // send CMD17
// SD_command(CMD17, addr, CMD17_CRC);
// read R1
res1 = SD_readRes1();
// // read R1
// res1 = SD_readRes1();
// if response received from card
if(res1 != 0xFF)
{
// wait for a response token (timeout = 100ms)
readAttempts = 0;
while(++readAttempts != SD_MAX_READ_ATTEMPTS)
if((read = spi_exchange(0xFF)) != 0xFF) break;
// // if response received from card
// if(res1 != 0xFF)
// {
// // wait for a response token (timeout = 100ms)
// readAttempts = 0;
// while(++readAttempts != SD_MAX_READ_ATTEMPTS)
// if((read = spi_exchange(0xFF)) != 0xFF) break;
// if response token is 0xFE
if(read == SD_START_TOKEN)
{
// read 512 byte block
for(i = 0; i < SD_BLOCK_LEN; i++) *buf++ = spi_exchange(0xFF);
// cprintf("read attempts: %d\r\n", readAttempts);
// read 16-bit CRC
spi_exchange(0xFF);
spi_exchange(0xFF);
}
// // if response token is 0xFE
// if(read == SD_START_TOKEN)
// {
// // read 512 byte block
// for(i = 0; i < SD_BLOCK_LEN; i++) *buf++ = spi_exchange(0xFF);
// set token to card response
*token = read;
}
// // read 16-bit CRC
// spi_exchange(0xFF);
// spi_exchange(0xFF);
// }
// deassert chip select
spi_exchange(0xFF);
spi_deselect(0);
spi_exchange(0xFF);
// // set token to card response
// *token = read;
// }
return res1;
}
// // deassert chip select
// spi_exchange(0xFF);
// spi_deselect(0);
// spi_exchange(0xFF);
// return res1;
// }
#define SD_MAX_WRITE_ATTEMPTS 3907