/*********************************************************************
* @fn writeItem
*
* @brief Writes an item header/data combo to the specified NV page.
*
* @param pg - Valid NV Flash page.
* @param id - Valid NV item Id.
* @param len - Byte count of the data to write.
* @param buf - The data to write. If NULL, no data/checksum write.
* @param flag - TRUE if the checksum should be written, FALSE otherwise.
*
* @return TRUE if header/data to write matches header/data read back, else FALSE.
*/
static uint8 writeItem( uint8 pg, uint16 id, uint16 len, void *buf, uint8 flag )
{
uint16 offset = pgOff[pg-OSAL_NV_PAGE_BEG];
uint8 rtrn = FALSE;
osalNvHdr_t hdr;
hdr.id = id;
hdr.len = len;
writeWord( pg, offset, (uint8 *)&hdr );
HalFlashRead(pg, offset, (uint8 *)(&hdr), OSAL_NV_HDR_SIZE);
if ( (hdr.id == id) && (hdr.len == len) )
{
if ( flag )
{
hdr.chk = calcChkB( len, buf );
offset += OSAL_NV_HDR_SIZE;
if ( buf != NULL )
{
writeBuf( pg, offset, len, buf );
}
if ( hdr.chk == calcChkF( pg, offset, len ) )
{
if ( hdr.chk == setChk( pg, offset, hdr.chk ) )
{
hotItemUpdate(pg, offset, hdr.id);
rtrn = TRUE;
}
}
}
else
{
rtrn = TRUE;
}
len = OSAL_NV_ITEM_SIZE( hdr.len );
}
else
{
len = OSAL_NV_ITEM_SIZE( hdr.len );
if (len > (OSAL_NV_PAGE_SIZE - pgOff[pg - OSAL_NV_PAGE_BEG]))
{
len = (OSAL_NV_PAGE_SIZE - pgOff[pg - OSAL_NV_PAGE_BEG]);
}
pgLost[pg - OSAL_NV_PAGE_BEG] += len;
}
pgOff[pg - OSAL_NV_PAGE_BEG] += len;
return rtrn;
}
/*********************************************************************
* @fn initItem
*
* @brief An NV item is created and initialized with the data passed to the function, if any.
*
* @param id - Valid NV item Id.
* @param len - Item data length.
* @param *buf - Pointer to item initalization data. Set to NULL if none.
*
* @return TRUE if item write and read back checksums ok; FALSE otherwise.
*/
static uint8 initItem( uint8 flag, uint16 id, uint16 len, void *buf )
{
uint16 sz = OSAL_NV_ITEM_SIZE( len );
uint8 rtrn = FALSE;
uint8 cnt = OSAL_NV_PAGES_USED;
uint8 pg = pgRes+1; // Set to 1 after the reserve page to even wear across all available pages.
uint8 idx;
do {
if (pg >= OSAL_NV_PAGE_BEG+OSAL_NV_PAGES_USED)
{
pg = OSAL_NV_PAGE_BEG;
}
if ( pg != pgRes )
{
idx = pg - OSAL_NV_PAGE_BEG;
if ( (pgOff[idx] - pgLost[idx] + sz) <= OSAL_NV_PAGE_FREE )
{
break;
}
}
pg++;
} while (--cnt);
if (cnt)
{
// Item fits if an old page is compacted.
if ( (pgOff[idx] + sz) > OSAL_NV_PAGE_FREE )
{
pg = pgRes;
}
// New item is the first one written to the reserved page, then the old page is compacted.
rtrn = writeItem( pg, id, len, buf, flag );
if ( pg == pgRes )
{
if ( flag )
{
compactPage( OSAL_NV_PAGE_BEG+idx );
}
else
{
*(uint8 *)buf = OSAL_NV_PAGE_BEG+idx;
}
}
}
return rtrn;
}
/*********************************************************************
* @fn initItem
*
* @brief An NV item is created and initialized with the data passed to the function, if any.
*
* @param flag - TRUE if the 'buf' parameter contains data for the call to writeItem().
* (i.e. if invoked from osal_nv_item_init() ).
* FALSE if writeItem() should just write the header and the 'buf' parameter
* is ok to use as a return value of the page number to be cleaned with
* COMPACT_PAGE_CLEANUP().
* (i.e. if invoked from osal_nv_write() ).
* @param id - Valid NV item Id.
* @param len - Item data length.
* @param *buf - Pointer to item initalization data. Set to NULL if none.
*
* @return The OSAL Nv page number if item write and read back checksums ok;
* OSAL_NV_PAGE_NULL otherwise.
*/
static uint8 initItem( uint8 flag, uint16 id, uint16 len, void *buf )
{
uint16 sz = OSAL_NV_ITEM_SIZE( len );
uint8 rtrn = OSAL_NV_PAGE_NULL;
uint8 cnt = OSAL_NV_PAGES_USED;
uint8 pg = pgRes+1; // Set to 1 after the reserve page to even wear across all available pages.
do {
if (pg >= OSAL_NV_PAGE_BEG+OSAL_NV_PAGES_USED)
{
pg = OSAL_NV_PAGE_BEG;
}
if ( pg != pgRes )
{
uint8 idx = pg - OSAL_NV_PAGE_BEG;
if ( sz <= (OSAL_NV_PAGE_SIZE - pgOff[idx] + pgLost[idx]) )
{
break;
}
}
pg++;
} while (--cnt);
if (cnt)
{
// Item fits if an old page is compacted.
if ( sz > (OSAL_NV_PAGE_SIZE - pgOff[pg - OSAL_NV_PAGE_BEG]) )
{
osalNvPgHdr_t pgHdr;
/* Prevent excessive re-writes to page header caused by numerous, rapid, & successive
* OSAL_Nv interruptions caused by resets.
*/
HalFlashRead(pg, OSAL_NV_PAGE_HDR_OFFSET, (uint8 *)(&pgHdr), OSAL_NV_PAGE_HDR_SIZE);
if ( pgHdr.xfer == OSAL_NV_ERASED_ID )
{
// Mark the old page as being in process of compaction.
sz = OSAL_NV_ZEROED_ID;
writeWordH( pg, OSAL_NV_PG_XFER, (uint8*)(&sz) );
}
/* First the old page is compacted, then the new item will be the last one written to what
* had been the reserved page.
*/
if (compactPage( pg, id ))
{
if ( writeItem( pgRes, id, len, buf, flag ) )
{
rtrn = pgRes;
}
if ( flag == FALSE )
{
/* Overload 'buf' as an OUT parameter to pass back to the calling function
* the old page to be cleaned up.
*/
*(uint8 *)buf = pg;
}
else
{
/* Safe to do the compacted page cleanup even if writeItem() above failed because the
* item does not yet exist since this call with flag==TRUE is from osal_nv_item_init().
*/
COMPACT_PAGE_CLEANUP( pg );
}
}
}
else
{
if ( writeItem( pg, id, len, buf, flag ) )
{
rtrn = pg;
}
}
}
return rtrn;
}