GIET-VM / RDK Driver

The rdk_driver.c​ and rdk_driver.h​ files define the RDK driver.

This driver supports a virtual disk implemented as a memory segment, in the physical address space.

It is one of the physical disk driver that can be called by the generic IOC driver.

The _rdk_read() and _rdk_write() blocking functions use a software memcpy, whatever the selected mode (BOOT / KERNEL / USER). These blocking functions return only when the transfer is completed. As the number of concurrent accesses is not bounded, these functions don't use the _ioc_lock variable.

The SEG_RDK_BASE virtual address must be defined in the hard_config.h file when the USE_RAMDISK flag is set.

#ifndef _GIET_RDK_DRIVERS_H_ #define _GIET_RDK_DRIVERS_H_

unsigned int _rdk_init()

This function does nothing, but is required by the generic IOC API.

unsigned int _rdk_read( unsigned int lba, unsigned int buffer, unsigned int count )

This function transfer data from the RAMDISK to a memory buffer.

• mode : BOOT / KERNEL / USER (unused)
• lba : first block index on the block device
• buffer : virtual base address of the memory buffer
• count : number of blocks to be transfered.

Returns 0 if success, > 0 if error.

unsigned int _rdk_write( unsigned int lba, unsigned int buffer, unsigned int count )

This function transfer data from a memory buffer to the RAMDISK.

• mode : BOOT / KERNEL / USER (unused)
• lba : first block index on the block device
• buffer : virtual base address of the memory buffer
• count : number of blocks to be transfered.

Returns 0 if success, > 0 if error.

unsigned int _rdk_get_block_size()

This function returns the block size.

unsigned int _rdk_get_status()

This function returns always 0, but is required bi the generic IOC API.