T-Kernel Specification (1.B0.02)

48 CHAPTER 4. T-KERNEL/OS FUNCTIONS
tk set cpr
Set Task Coprocessor Registers
[C Language Interface]
ER ercd = tk_set_cpr ( ID tskid, INT copno, T_COPREGS *pk_copregs ) ;
[Parameters]
ID tskid Task ID
INT copno Coprocessor number (0 to 3)
T COPREGS pk copregs Coprocessor registers
[Return Parameters]
ER ercd Error code
[Error Codes]
E OK
E ID
E NOEXS
E OBJ
E CTX
E PAR
Normal completion
Invalid ID number (tskid is invalid or cannot be used)
Object does not exist (the task designated in tskid does not exist)
Invalid object state (called for the invoking task)
Context error (called from task-independent portion)
Parameter error (copno is invalid or the designated coprocessor does not exist), or the
set register value is invalid (implementation-dependent)
[Description]
Sets the contents of the register designated in copno of the task designated in tskid.
The set register values are not necessarily the values while the task portion is executing. The OS is not
aware of the effects of register value changes. It is possible, however, that some registers or register bits
cannot be changed if the OS does not allow such changes (implementation-dependent).
If this system call is issued for the invoking task, error code E OBJ is returned.
Copyright c○ 2002, 2003 by T-Engine Forum
T-Kernel 1.B0.02