KThreadContext

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Revision as of 15:45, 29 August 2016 by Bond697 (talk | contribs) (Undo revision 18002 by Neobrain (talk))
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Size : 0x1000 bytes (1 page)


Offset Type Description
0xF38 u32[4] SVC access control data copied from KThread's owner process
0xF50 u32[10] SVC mode registers, r4-r11, r13, r14
0xFF8 u32 FPEXC, floating point exception register for thread- stored and loaded on context switches

When switching thread contexts the kernel does, in order:

  • Load FPEXC
  • Save the LR to r1- this LR is the return back to the main scheduling and context switching function
  • Load r4-r11, SP, LR
  • Branch back to r1, preserving the LR which was just reloaded, back to the main scheduling function, but in the context of the newly switched-to thread
  • Disable Interrupts
  • Check if that core's KScheduler object indicates that it needs switching again and exit if it does not
  • Otherwise, run the thread scheduler again and repeat all the steps to switch contexts again