FORTUNE -- Samsung, believe it or not, is still the sole supplier of the processors that run every iPhone, iPad and iPod touch that Apple (AAPL) sells.
On the assumption that Tim Cook will not want to be forever dependent on a company that he claims has stolen Apple's intellectual property and as everyone can see is rapidly gobbling up smartphone market share, RBC Capital's Amit Daryanani took a look Friday at Apple's alternatives.
It's not going to be easy to switch suppliers, he writes. Apple did most of the heavy lifting on the A6 chips in the current generation of iPhones and iPads -- designing the processors in-house and paying Samsung to manufacture them. Nonetheless, moving its business to a different foundry would require, according to Daryanani, "a complete redo" that would take a minimum of 12 to 18 months, cost a fortune and not produce marketable chips before 2014. New fabs start at $1-3 billion. In 2010, TSMC budgeted $9.3 billion to build a massive chip foundry in central Taiwan.
So where might Apple take its business? Daryanani offers four possibilities: (I quote his spec-heavy prose)
UPDATE: RBC's Freedman says Intel already in talks with Apple to build iPhone processors
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