///////////////////////////////////////////////////////////////////////////////////
// File      : rdk_driver.c
// Date      : 13/02/2014
// Author    : alain greiner
// Maintainer: cesar fuguet
// Copyright (c) UPMC-LIP6
///////////////////////////////////////////////////////////////////////////////////
// The rdk_driver.c and rdk_driver.h files are part ot the GIET-VM kernel.
//
// This driver supports a virtual disk implemented as a memory segment, 
// in the address space. 
//
// The _rdk_read() and _rdk_write() blocking functions use a software memcpy,
// whatever the selected mode. They 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.
///////////////////////////////////////////////////////////////////////////////////

#include <giet_config.h>
#include <rdk_driver.h>
#include <utils.h>
#include <tty_driver.h>
#include <ctx_handler.h>

///////////////////////////////////////////////////////////////////////////////
//       _rdk_init()
// This function does nothing, and return 0 for success.
///////////////////////////////////////////////////////////////////////////////
unsigned int _rdk_init( unsigned int channel )
{
    return 0;
}

///////////////////////////////////////////////////////////////////////////////
//     _rdk_read()
// Transfer data from the RAMDISK to a memory buffer. 
// - mode     : BOOT / KERNEL / USER
// - 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_read( unsigned int lba, 
                        unsigned int buffer, 
                        unsigned int count) 
{

#if GIET_DEBUG_IOC_DRIVER
_tty_get_lock( 0 );
_puts("\n[IOC DEBUG] Enter _rdk_read() at cycle ");
_putd( _get_proctime() );
_puts(" for processor ");
_putd( _get_procid() );
_puts("\n - vaddr   = ");
_putx( buffer );
_puts("\n - sectors = ");
_putd( count );
_puts("\n - lba     = ");
_putx( lba );
_puts("\n");
_tty_release_lock( 0 );
#endif

    char* src = (char*)&seg_ram_disk_base + (512*lba);
    char* dst = (char*)buffer;
    _memcpy( dst, src, count*512 );

    return 0;
}

///////////////////////////////////////////////////////////////////////////////
//     _rdk_write()
// Transfer data from a memory buffer to the block device. 
// - mode     : BOOT / KERNEL / USER
// - 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 ) 
{

#if GIET_DEBUG_IOC_DRIVER
_tty_get_lock( 0 );
_puts("\n[IOC DEBUG] Enter _rdk_write() at cycle ");
_putd( _get_proctime() );
_puts(" for processor ");
_putd( _get_procid() );
_puts("\n - vaddr   = ");
_putx( buffer );
_puts("\n - sectors = ");
_putd( count );
_puts("\n - lba     = ");
_putx( lba );
_puts("\n");
_tty_release_lock( 0 );
#endif

    char* dst = (char*)&seg_ram_disk_base + (512*lba);
    char* src = (char*)buffer;
    _memcpy( dst, src, count*512 );

    return 0;
}

///////////////////////////////////////////////////////////////////////////////
//     _rdk_get_block_size()
// This function returns the block_size.
///////////////////////////////////////////////////////////////////////////////
unsigned int _rdk_get_block_size() 
{
    return 512;
}


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