= GIET-VM / CP0 access functions =

[[PageOutline]]

The [source:soft/giet_vm/giet_common/utils.c utils.c] and [source:soft/giet_vm/giet_common/utils.h util.h] files define kernel functions that are used both by the boot-loader and by the kernel. 
They are prefixed by ''_'' to remind that they can only be executed by a processor in kernel mode.

 === static_scheduler_t* '''_get_sched'''( void ) ===
Returns the virtual address of the scheduler, stored in the CP0_SCHED register, for the processor running the calling task. 

 === unsigned int '''_get_epc'''( void ) ===
Returns the value stored in the CP0_EPC register, for the processor running the calling task.  

 === unsigned int '''_get_cr'''( void ) ===
Returns the value stored in the CP0_CR register, for the processor running the calling task. 

 === unsigned int '''_get_sr'''( void ) ===
Returns the value stored in the CP0_SR register, for the processor running the calling task. 

 === unsigned int '''_get_bvar'''( void ) ===
Returns the value stored in the CP0_BVAR register, for the processor running the calling task. 

 === unsigned int '''_get_procid'''( void ) ===
Returns the global processor identifier stored in the CP0_PROCID register for the processor running the calling task. 

 === unsigned int '''_get_proctime'''( void ) ===
Returns the cycle count stored in the CP0_TIME register for the processor running the calling task. 

 === void _'''set_sched'''( unsigned int value ) ===
Writes ''value'' in the CP0_SCHED register, for the processor running the calling task. 

 === void '''_set_sr'''( unsigned int value ) ===
Writes ''value'' in the CP0_SR register, for the processor running the calling task. 

 === void '''_it_disable'''( unsigned int* save_sr_ptr ) ===
Disables interrupts for the processor running the calling task and save the CP0_SR value at address ''save_sr_ptr''.

 === void '''_it_restore'''( unsigned int* save_sr_ptr ) ===
Writes the value pointed by ''save_sr_ptr'' into the CP0_SR register, for the processor running the calling task.