GIET-VM / SDC Driver

The sdc_driver.c​ and sdc_driver.h​ files define the SDC driver.

This component is a single channel, block oriented, external mass storage peripheral, implemented on a SD card.

The sdc_driver uses the lower level spi_driver to access the SD card.

The sdc_driver is called by the generic ioc_driver when the USE_IOC_SPI flag is set in the hard_config.h file.

The SEG_IOC_BASE address must be defined in the hard_config.h file.

In this implementation, the SDC peripheral is acting as a target (no DMA capability) : the _sdc_read() and _sdc_write() are blocking until the transfer is fully completed, and does not use any interrupt to signal completion.

WARNING : The _sdc_write() function is not implemented yet

unsigned int _sdc_init()

This function initializes the SPI controller and call sdc_open to initialize the SD card. Returns 0 if success, >0 if failure

unsigned int _sdc_read( unsigned int mode, unsigned int lba, paddr_t buffer, unsigned int count )

Transfer data from the SD card to a memory buffer.

• mode : BOOT / KERNEL / USER (Not used in this implementation)
• lba : first block index on the SD card
• buffer : physical base address of the memory buffer
• count : number of blocks to be transfered.

Returns 0 if success, > 0 if error.

unsigned int _sdc_write( unsigned int mode, unsigned int lba, paddr_t buffer, unsigned int count )

Transfer data from a memory buffer to the SD card.

• mode : BOOT / KERNEL / USER (Not used in this implementation)
• lba : first block index on the SD card.
• buffer : physical base address of the memory buffer
• count : number of blocks to be transfered.

Returns 0 if success, > 0 if error. WARNING: The _sdc_write() is not implemented yet.

unsigned int _sdc_get_status()

This function should not be called for this implementation of the SDC driver (No DMA).

unsigned int _sdc_get_block_size()

Returns the block size (bytes).