/*********************************************************************
* @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 initNV
*
* @brief Initialize the NV flash pages.
*
* @param none
*
* @return TRUE if initialization succeeds. FALSE, otherwise.
*/
static uint8 initNV( void )
{
uint32 pgHdr;
uint8 xferPg = OSAL_NV_PAGE_NULL;
uint8 pg;
failF = FALSE;
activePg = OSAL_NV_PAGE_NULL;
// Pick active page and clean up erased page if necessary
for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
{
HalFlashRead(pg, OSAL_NV_PAGE_HDR_OFFSET, (uint8 *)(&pgHdr), OSAL_NV_PAGE_HDR_SIZE);
if ( pgHdr == OSAL_NV_ACTIVE_PAGE_STATE)
{
if (activePg != OSAL_NV_PAGE_NULL)
{
// Both pages are active only when power failed during flash erase and
// with very low probability.
// As it is hard (code size intensive) to figure out which page is the real active page,
// and theoretically impossible as well in lowest probability, erase both pages
// in this case
cleanErasedPage(activePg);
cleanErasedPage(pg);
activePg = OSAL_NV_PAGE_NULL;
}
else
{
activePg = pg;
}
}
else if ( pgHdr == OSAL_NV_XFER_PAGE_STATE)
{
xferPg = pg;
}
else
{
// Erase this page if it is not erased.
// This is to ensure that any page that were in the middle of
// compacting gets erased.
cleanErasedPage(pg);
}
}
if (activePg == OSAL_NV_PAGE_NULL)
{
if (xferPg == OSAL_NV_PAGE_NULL)
{
// Both pages are erased. This must be initial state.
// Pick one page as active page.
setActivePage(OSAL_NV_PAGE_BEG);
pgOff = OSAL_NV_PAGE_HDR_SIZE;
// If setting active page from a completely erased page failed,
// it is not recommended to operate any further.
// Other cases, even if non-active page is corrupt, NV module can still read
// the active page content and hence this function could return TRUE.
return (!failF);
}
else
{
// Compacting a page hasn't completed in previous power cycle.
// Complete the compacting.
activePg = xferPg;
findOffset();
compactPage(xferPg);
}
}
else
{
if (xferPg != OSAL_NV_PAGE_NULL)
{
// Compacting has completed except for the final step of erasing
// the xferPage.
erasePage(xferPg);
}
// find the active page offset to write a new variable location item
findOffset();
}
return TRUE;
}
/*********************************************************************
* @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;
}
/*********************************************************************
* @fn initNV
*
* @brief Initialize the NV flash pages.
*
* @param none
*
* @return TRUE
*/
static uint8 initNV( void )
{
osalNvPgHdr_t pgHdr;
uint8 oldPg = OSAL_NV_PAGE_NULL;
uint8 newPg = OSAL_NV_PAGE_NULL;
uint8 findDups = FALSE;
uint8 pg;
pgRes = OSAL_NV_PAGE_NULL;
for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
{
HalFlashRead(pg, OSAL_NV_PAGE_HDR_OFFSET, (uint8 *)(&pgHdr), OSAL_NV_HDR_SIZE);
if ( pgHdr.active == OSAL_NV_ERASED_ID )
{
if ( pgRes == OSAL_NV_PAGE_NULL )
{
pgRes = pg;
}
else
{
setPageUse( pg, TRUE );
}
}
else // Page is active.
{
// If the page is not yet in use, it is the tgt of items from an xfer.
if ( pgHdr.inUse == OSAL_NV_ERASED_ID )
{
newPg = pg;
}
// An Xfer from this page was in progress.
else if ( pgHdr.xfer != OSAL_NV_ERASED_ID )
{
oldPg = pg;
}
}
// Calculate page offset and lost bytes - any "old" item triggers an N^2 re-scan from start.
if ( initPage( pg, OSAL_NV_ITEM_NULL, findDups ) != OSAL_NV_ITEM_NULL )
{
findDups = TRUE;
pg = OSAL_NV_PAGE_BEG-1;
continue;
}
} // for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
/* First the old page is erased, and then the new page is put into use.
* So if a transfer was in progress, the new page will always not yet be
* marked as in use, since that is the last step to ending a transfer.
*/
if ( newPg != OSAL_NV_PAGE_NULL )
{
/* If there is already a fallow page reserved, keep it and put the newPg in use.
* An unfinished compaction will finish to the new reserve page and the old page
* will be erased and reserved.
*/
if ( pgRes != OSAL_NV_PAGE_NULL )
{
setPageUse( newPg, TRUE );
}
/* If setting old page to 'xfer' failed or board reset before it was effected, there is no way
* to know which page was the 'old page' - so just reset all NV pages to start clean.
*/
else if ( oldPg != OSAL_NV_PAGE_NULL )
{
pgRes = newPg;
}
/* If a page compaction was interrupted and the page being compacted is not
* yet erased, then there may be items remaining to xfer before erasing.
*/
if ( oldPg != OSAL_NV_PAGE_NULL )
{
compactPage( oldPg );
}
}
/* If no page met the criteria to be the reserve page:
* - A compactPage() failed or board reset before doing so.
* - Perhaps the user changed which Flash pages are dedicated to NV and downloaded the code
* without erasing Flash?
*/
if ( pgRes == OSAL_NV_PAGE_NULL )
{
for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
{
erasePage( pg );
}
initNV();
}
return TRUE;
}
/*********************************************************************
* @fn initNV
*
* @brief Initialize the NV flash pages.
*
* @param none
*
* @return TRUE
*/
static uint8 initNV( void )
{
osalNvPgHdr_t pgHdr;
uint8 oldPg = OSAL_NV_PAGE_NULL;
uint8 findDups = FALSE;
uint8 pg;
pgRes = OSAL_NV_PAGE_NULL;
for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
{
HalFlashRead(pg, OSAL_NV_PAGE_HDR_OFFSET, (uint8 *)(&pgHdr), OSAL_NV_HDR_SIZE);
if ( pgHdr.active == OSAL_NV_ERASED_ID )
{
if ( pgRes == OSAL_NV_PAGE_NULL )
{
pgRes = pg;
}
else
{
setPageUse( pg, TRUE );
}
}
// An Xfer from this page was in progress.
else if ( pgHdr.xfer != OSAL_NV_ERASED_ID )
{
oldPg = pg;
}
}
// If a page compaction was interrupted before the old page was erased.
if ( oldPg != OSAL_NV_PAGE_NULL )
{
/* Interrupted compaction before the target of compaction was put in use;
* so erase the target of compaction and start again.
*/
if ( pgRes != OSAL_NV_PAGE_NULL )
{
erasePage( pgRes );
(void)compactPage( oldPg, OSAL_NV_ITEM_NULL );
}
/* Interrupted compaction after the target of compaction was put in use,
* but before the old page was erased; so erase it now and create a new reserve page.
*/
else
{
erasePage( oldPg );
pgRes = oldPg;
}
}
else if ( pgRes != OSAL_NV_PAGE_NULL )
{
erasePage( pgRes ); // The last page erase could have been interrupted by a power-cycle.
}
/* else if there is no reserve page, COMPACT_PAGE_CLEANUP() must have succeeded to put the old
* reserve page (i.e. the target of the compacted items) into use but got interrupted by a reset
* while trying to erase the page to be compacted. Such a page should only contain duplicate items
* (i.e. all items will be marked 'Xfer') and thus should have the lost count equal to the page
* size less the page header.
*/
for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
{
// Calculate page offset and lost bytes - any "old" item triggers an N^2 re-scan from start.
if ( initPage( pg, OSAL_NV_ITEM_NULL, findDups ) != OSAL_NV_ITEM_NULL )
{
findDups = TRUE;
pg = (OSAL_NV_PAGE_BEG - 1); // Pre-decrement so that loop increment will start over at zero.
continue;
}
}
if (findDups)
{
// Final pass to calculate page lost after invalidating duplicate items.
for ( pg = OSAL_NV_PAGE_BEG; pg <= OSAL_NV_PAGE_END; pg++ )
{
(void)initPage( pg, OSAL_NV_ITEM_NULL, FALSE );
}
}
if ( pgRes == OSAL_NV_PAGE_NULL )
{
uint8 idx, mostLost = 0;
for ( idx = 0; idx < OSAL_NV_PAGES_USED; idx++ )
{
// Is this the page that was compacted?
if (pgLost[idx] == (OSAL_NV_PAGE_SIZE - OSAL_NV_PAGE_HDR_SIZE))
{
mostLost = idx;
break;
}
/* This check is not expected to be necessary because the above test should always succeed
* with an early loop exit.
*/
else if (pgLost[idx] > pgLost[mostLost])
{
mostLost = idx;
}
}
pgRes = mostLost + OSAL_NV_PAGE_BEG;
erasePage( pgRes ); // The last page erase had been interrupted by a power-cycle.
}
return TRUE;
}