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Code Issues Releases Wiki Activity

Update README files

This commit is contained in:
Gregory Nutt 2016-11-01 15:12:30 -06:00
parent 099b1f94a3
commit abf5b011b5
2 changed files with 19 additions and 2 deletions
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17
configs/esp32-core/README.txt
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@ -23,6 +23,7 @@ Contents
o Buttons and LEDs
o SMP
o Configurations
o Things to Do
STATUS
======
@ -196,3 +197,19 @@ NOTES:
SMP operation.
NOTES:
Things to Do
============
1. There is no support for an interrupt stack yet.
2. I did not implement the lazy co-processor save logic supported by Xtensa. That logic works like this:
a. CPENABLE is set to zero on each context switch, disabling all co-processors.
b. If/when the task attempts to use the disabled co-processor, an exception occurs
c. The co-processor exception handler re-enables the co-processor.
Instead, the NuttX logic saves and restores CPENABLE on each context switch.
3. Currently the Xtensa port copies register state save information from the stack into the TCB. A more efficient alternative would be to just save a pointer to a register state save area in the TCB. This would add some complexity to signal handling and also also the the up_initialstate(). But the performance improvement might be worth the effort.
4. See SMP-related issues above