Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/

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Gregory Nutt 79fa2a7b09 ARMv7-A: Modify up_fullcontextrestore() for CONFIG_BUILD_KERNEL. It changed CPSR while in kernel. That will crash is the new CPSR is user mode while executing in kernel space. Fixed by adding a SYS_context_restore system call. There is an alternative, simpler modification to up_fullcontextrestore() that could have been done: It might have been possible to use the SPSR instead of the CPRSR and then do an exception return from up_fullcontextrestore(). That would be more efficient, but I never tried it.		2014-09-12 08:04:27 -06:00
configs	ARMv7-A: Modify up_fullcontextrestore() for CONFIG_BUILD_KERNEL. It changed CPSR while in kernel. That will crash is the new CPSR is user mode while executing in kernel space. Fixed by adding a SYS_context_restore system call. There is an alternative, simpler modification to up_fullcontextrestore() that could have been done: It might have been possible to use the SPSR instead of the CPRSR and then do an exception return from up_fullcontextrestore(). That would be more efficient, but I never tried it.	2014-09-12 08:04:27 -06:00