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/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/nvs.h>
/** @file
*
* Non-volatile storage
*
*/
/**
* Calculate length up to next block boundary
*
* @v nvs NVS device
* @v address Starting address
* @v max_len Maximum length
* @ret len Length to use, stopping at block boundaries
*/
static size_t nvs_frag_len ( struct nvs_device *nvs, unsigned int address,
size_t max_len ) {
size_t frag_len;
/* If there are no block boundaries, return the maximum length */
if ( ! nvs->block_size )
return max_len;
/* Calculate space remaining up to next block boundary */
frag_len = ( ( nvs->block_size -
( address & ( nvs->block_size - 1 ) ) )
<< nvs->word_len_log2 );
/* Limit to maximum length */
if ( max_len < frag_len )
return max_len;
return frag_len;
}
/**
* Read from non-volatile storage device
*
* @v nvs NVS device
* @v address Address from which to read
* @v data Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
int nvs_read ( struct nvs_device *nvs, unsigned int address,
void *data, size_t len ) {
size_t frag_len;
int rc;
/* We don't even attempt to handle buffer lengths that aren't
* an integral number of words.
*/
assert ( ( len & ( ( 1 << nvs->word_len_log2 ) - 1 ) ) == 0 );
while ( len ) {
/* Calculate length to read, stopping at block boundaries */
frag_len = nvs_frag_len ( nvs, address, len );
/* Read this portion of the buffer from the device */
if ( ( rc = nvs->read ( nvs, address, data, frag_len ) ) != 0 )
return rc;
/* Update parameters */
data += frag_len;
address += ( frag_len >> nvs->word_len_log2 );
len -= frag_len;
}
return 0;
}
/**
* Verify content of non-volatile storage device
*
* @v nvs NVS device
* @v address Address from which to read
* @v data Data to compare against
* @v len Length of data buffer
* @ret rc Return status code
*/
static int nvs_verify ( struct nvs_device *nvs, unsigned int address,
const void *data, size_t len ) {
uint8_t read_data[len];
int rc;
/* Read data into temporary buffer */
if ( ( rc = nvs_read ( nvs, address, read_data, len ) ) != 0 )
return rc;
/* Compare data */
if ( memcmp ( data, read_data, len ) != 0 ) {
DBG ( "NVS %p verification failed at %#04x+%zd\n",
nvs, address, len );
return -EIO;
}
return 0;
}
/**
* Write to non-volatile storage device
*
* @v nvs NVS device
* @v address Address to which to write
* @v data Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
int nvs_write ( struct nvs_device *nvs, unsigned int address,
const void *data, size_t len ) {
size_t frag_len;
int rc;
/* We don't even attempt to handle buffer lengths that aren't
* an integral number of words.
*/
assert ( ( len & ( ( 1 << nvs->word_len_log2 ) - 1 ) ) == 0 );
while ( len ) {
/* Calculate length to write, stopping at block boundaries */
frag_len = nvs_frag_len ( nvs, address, len );
/* Write this portion of the buffer to the device */
if ( ( rc = nvs->write ( nvs, address, data, frag_len ) ) != 0)
return rc;
/* Read back and verify data */
if ( ( rc = nvs_verify ( nvs, address, data, frag_len ) ) != 0)
return rc;
/* Update parameters */
data += frag_len;
address += ( frag_len >> nvs->word_len_log2 );
len -= frag_len;
}
return 0;
}
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