#11315 NORM 1.75-fi: XO 1.75 secure mode gets ttyS0 console instead of ttyS2

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#11315: XO 1.75 secure mode gets ttyS0 console instead of ttyS2
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           Reporter:  greenfeld            |       Owner:  wmb at firmworks.com                
               Type:  defect               |      Status:  assigned                         
           Priority:  normal               |   Milestone:  1.75-firmware                    
          Component:  ofw - open firmware  |     Version:  Development build as of this date
         Resolution:                       |    Keywords:                                   
        Next_action:  diagnose             |    Verified:  0                                
Deployment_affected:                       |   Blockedby:                                   
           Blocking:                       |  
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Changes (by dsd):

 * cc: pgf (added)


Comment:

 Discussion/clarification with Paul on IRC:

 If we make this change, if you downgrade OS on a secure laptop, you'll
 lose serial console kernel messages, but only on secure laptops. VT
 consoles remain available, and the bash prompt over serial still works.
 The framebuffer font size will be small during early boot, but will
 correct itself when userspace starts. The  only breakage is to
 convenience, not function.

 This would be noticable if you had a secure laptop with a broken screen
 and broken serial input, and it was secure, and you downgraded the OS. But
 first debugging steps in such a situation could be replace the screen and
 get a devkey.

 One slight downside: settings in CONFIG_CMDLINE cannot be tweaked
 trivially - you have to rebuild the kernel. However, this has not been an
 issue for the existing settings we have in CONFIG_CMDLINE. In the case of
 the parameters questioned by this ticket, you would have to change
 CONFIG_CMDLINE if you want to disable serial console or change the early
 boot console font - not things we do often.

 Overall Paul agrees with this plan of action.

 So the next steps I propose are:
  * remove these parameters from OFW
  * do a new OFW release for XO-1.75
  * I'll then update the XO-1.75 kernel branch to remove these parameters
 from olpc.fth, and put them in CONFIG_CMDLINE. This bug will then be fixed
 for XO-1.75 for 11.3.0.
  * I'll note on #11214 what needs to be done for XO-1 and XO-1.5 for
 future releases once new firmwares are built for those laptops, and I'll
 follow through at a later date.

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Ticket URL: <http://dev.laptop.org/ticket/11315#comment:6>
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