Commit Graph

1 Commits

Author SHA1 Message Date
Michael Hope 42accf2e64 disk: add a SDHC card over SPI driver.
Features:

- Uses the SPI bus to communicate with the card
- Detects and safely rejects SDSC (<= 2 GiB) cards
- Uses the optional CRC support for data integrity
- Retries resumable errors like CRC failure or temporary IO failure
- Works well with ELMFAT
- When used on a device with a FIFO or DMA, achieves >= 310 KiB/s on a
  4 MHz bus

Tested on a mix of SanDisk, Samsung, 4V, and ADATA cards from 4 GiB to
32 GiB.

Signed-off-by: Michael Hope <mlhx@google.com>
2018-12-30 16:24:10 -05:00