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Diffstat (limited to 'nuttx/TODO')
| -rw-r--r-- | nuttx/TODO | 23 |
1 files changed, 1 insertions, 22 deletions
diff --git a/nuttx/TODO b/nuttx/TODO index 91b4aebaa..94c3dba0d 100644 --- a/nuttx/TODO +++ b/nuttx/TODO @@ -21,7 +21,7 @@ nuttx/ (1) Documentation (Documentation/) (7) Build system / Toolchains (5) Linux/Cywgin simulation (arch/sim) - (6) ARM (arch/arm/) + (5) ARM (arch/arm/) (1) ARM/C5471 (arch/arm/src/c5471/) (3) ARM/DM320 (arch/arm/src/dm320/) (2) ARM/i.MX (arch/arm/src/imx/) @@ -1176,27 +1176,6 @@ o ARM (arch/arm/) Status: Open Priority: Low - Title: SVCALLS AND HARDFAULTS - Description: The Cortex-M3 user context switch logic uses SVCall instructions. - This user context switching time could be improved by eliminating - the SVCalls and developing assembly language implementations - of the context save and restore logic. - Also, because interrupts are always disabled when the SVCall is - executed, the SVC goes to the hard fault handler where it must - be handled as a special case. I recall seeing some controls - somewhere that will allow to suppress one hard fault. I don't - recall the control, but something like this should be used before - executing the SVCall so that it vectors directly to the SVC - handler. - Another, more standard option would be to use interrupt priority - levels to control interrupts. In that case, (1) The SVC would - be the highest priority interrupt (0), (2) irqsave() would set - the interrupt mask level to just above that, and (2) irqrestore - would restore the interrupt level. This would not be diffult, - but does affect a lot of files! - Status: Open - Priority: Low - Title: ARM INTERRUPTS AND USER MODE Description: The ARM interrupt handling (arch/arm/src/arm/up_vectors.S) returns using 'ldmia sp, {r0-r15}^' My understanding is that this works |