GIET-VM / Syscall Handler functions

The sys_handler.c​ and sys_handler.h​ files define the kernel data structure and functions that are used to handle the system calls. They are prefixed by _ to remind that they can only be executed by a processor in kernel mode.

The _syscall_vector![64!​] array contains the 64 kernel functions defined by the GIET-VM to handle system calls. Most of these functions are provided by the peripheral drivers, but some services are provided by the kernel itself:

void _sys_ukn()

Function executed in case of undefined syscall

void _proc_xyp( unsigned int* x, unsigned int*, unsigned int* p )

This function returns the processor (x,y,p) identifiers.

void _task_exit()

The calling task goes to sleeping state, after printing an exit message. It is descheduled and enters the "not runable" mode.

void _context_switch()

This function deschedules the calling task. It mask interrupts before calling the _ctx_switch, and restore it when the task is rescheduled.

unsigned int _local_task_id()

Returns current task local index (amongst tasks running on a given processor).

unsigned int _global_task_id()

Returns current task global index (amongst all tasks running on all processors).

unsigned int _thread_id()

Returns current thread index (amongst all tasks in a given multi-tasks application).

unsigned int _procs_number( unsigned int cluster_id, unsigned int* number )

Returns in buffer argument the number of processors in cluster specified by the cluster_id argument.

unsigned int _get_vobj_ptr( char* vspace_name, char* vobj_name, mapping_vobj_t pvobj )

This function returns in the res_vobj argument a pointer on a vobj identified by the (vspace_name / vobj_name ) couple. Returns 0 if success, >0 if not found

/ This function writes in vobj_vbase the virtual base address of a vobj identified by the (vspace_name / vobj_name ) couple. returns 0 if success, >0 if not found / unsigned int _vobj_get_vbase( char* vspace_name,

char* vobj_name, unsigned int* vobj_vbase );

/ This function writes in vobj_length the length of a vobj identified by the (vspace_name / vobj_name ) couple. returns 0 if success, >0 if not found / unsigned int _vobj_get_length( char* vspace_name,

char* vobj_name, unsigned int* vobj_length );

unsigned int _get_xy_from_ptr( void* ptr, unsigned int* px, unsigned int* py )

This function returns in the (x,y) arguments the coordinates of the cluster where is mapped the ptr virtual address. It use the _get_context_slot() function to get the calling task page table, and uses the _v2p_translate() function to obtain the physical address. Returns 0 if success, > 0 if ptr not mapped in the calling task vspace.