Neil is correct, you will either get fastq output or sam/bam. For both exist converters and filters (the qualities serve a purpose) to fasta.
And most NGS tools actually use fastq not fasta as input.
The above answer is pretty comprehensive, but if indeed you want to go from FASTQ to FASTA, then the FASTX toolkit--among many other programs--has a module for that:
What have you tried so far? Google suggests that conversion to FASTQ, rather than FASTA, might be what you want.
Similar question here: Converting Bcl To Fastq
I think the best solution right now is bcl2fastq: http://support.illumina.com/downloads/bcl2fastq_conversion_software_184.html. It is a standalone app released by Illumina, although it may not be supported in the future as they put more resources into BaseSpace.