[OLPC-devel] Re: [One Laptop Per Child] #53: LinuxBIOS sometimes hangs after "Jumping to LinuxBIOS"

[Zarro Boogs per Child]

#53: LinuxBIOS sometimes hangs after "Jumping to LinuxBIOS"
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 Reporter:  wmb at firmworks.com  |        Owner:  mfoster   
     Type:  defect             |       Status:  new       
 Priority:  blocker            |    Milestone:  rev1 alpha
Component:  linuxbios          |   Resolution:            
 Keywords:                     |  
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Comment (by wmb at firmworks.com):

 A bit of perspective on issues of this ilk: In my experience at FirmWorks
 and other companies, dealing with the quirks of different memory chips and
 their interactions with specific memory controller core logic is one of
 the most time-consuming parts of a production-quality firmware port.  In
 principle, the information in a memory DIMM's SPD ROM should be sufficient
 to autoconfigure a memory controller.  In practice, it hardly ever works
 out that cleanly.  You always seem to run across some memory devices where
 the calculated timings just don't quite work.

 And when you have to deal with soldered-down RAM that doesn't have SPD at
 all, it's even worse, unless you stick to one specific memory chip.

 The difference between vendors whose systems "just work" and the rest of
 the pack is that the former do extensive tests to qualify specific parts,
 and then stick to those parts, whereas the latter use whatever is easy to
 get that week.  It takes a lot of discipline to do the qualification and
 stick to it(and requalifying in the face of component shortages is
 expensive), but the companies that do it are household names, while those
 who don't are here today, gone tomorrow.

-- 
Ticket URL: <http://dev.laptop.org/ticket/53#comment:27>
One Laptop Per Child <http://laptop.org/>