+
+ if(!dev->eraseBlockInNAND)
+ return 0;
+ T(YAFFS_TRACE_CHECKPOINT,(TSTR("checking blocks %d to %d"TENDSTR),
+ dev->startBlock,dev->endBlock));
+
+ for(i = dev->startBlock; i <= dev->endBlock; i++) {
+ yaffs_BlockInfo *bi = &dev->blockInfo[i];
+ if(bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT){
+ T(YAFFS_TRACE_CHECKPOINT,(TSTR("erasing checkpt block %d"TENDSTR),i));
+ if(dev->eraseBlockInNAND(dev,i)){
+ bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
+ dev->nErasedBlocks++;
+ dev->nFreeChunks += dev->nChunksPerBlock;
+ }
+ else {
+ dev->markNANDBlockBad(dev,i);
+ bi->blockState = YAFFS_BLOCK_STATE_DEAD;
+ }
+ }
+ }
+
+ dev->blocksInCheckpoint = 0;
+
+ return 1;
+}
+
+
+static void yaffs_CheckpointFindNextErasedBlock(yaffs_Device *dev)
+{
+ int i;
+ int blocksAvailable = dev->nErasedBlocks - dev->nReservedBlocks;
+
+ if(dev->checkpointNextBlock >= 0 &&
+ dev->checkpointNextBlock <= dev->endBlock &&
+ blocksAvailable > 0){
+
+ for(i = dev->checkpointNextBlock; i <= dev->endBlock; i++){
+ yaffs_BlockInfo *bi = &dev->blockInfo[i];
+ if(bi->blockState == YAFFS_BLOCK_STATE_EMPTY){
+ dev->checkpointNextBlock = i + 1;
+ dev->nErasedBlocks--;
+ dev->checkpointCurrentBlock = i;
+ T(YAFFS_TRACE_CHECKPOINT,(TSTR("allocating checkpt block %d"TENDSTR),i));
+ return;
+ }
+ }
+ }
+ T(YAFFS_TRACE_CHECKPOINT,(TSTR("out of checkpt blocks"TENDSTR)));
+
+ dev->checkpointNextBlock = -1;
+ dev->checkpointCurrentBlock = -1;
+}
+
+static void yaffs_CheckpointFindNextCheckpointBlock(yaffs_Device *dev)
+{
+ int i;
+ yaffs_ExtendedTags tags;
+
+ if(dev->blocksInCheckpoint < dev->checkpointMaxBlocks)
+ for(i = dev->checkpointNextBlock; i <= dev->endBlock; i++){
+ int chunk = i * dev->nChunksPerBlock;
+
+ dev->readChunkWithTagsFromNAND(dev,chunk,NULL,&tags);
+
+ if(tags.sequenceNumber == YAFFS_SEQUENCE_CHECKPOINT_DATA){
+ /* Right kind of block */
+ dev->checkpointNextBlock = tags.objectId;
+ dev->checkpointCurrentBlock = i;
+ dev->checkpointBlockList[dev->blocksInCheckpoint] = i;
+ dev->blocksInCheckpoint++;
+ T(YAFFS_TRACE_CHECKPOINT,(TSTR("found checkpt block %d"TENDSTR),i));
+ return;
+ }
+ }
+
+ T(YAFFS_TRACE_CHECKPOINT,(TSTR("found no more checkpt blocks"TENDSTR)));
+
+ dev->checkpointNextBlock = -1;
+ dev->checkpointCurrentBlock = -1;
+}
+
+
+int yaffs_CheckpointOpen(yaffs_Device *dev, int forWriting)
+{
+