OS_AddToVector (changes)
Showing changes from revision #3 to #4:
Added | Removed | Changed
OS SWI Calls
» OS_AddToVector
OS_AddToVector
(SWI &47)
| Entry | |
|---|---|
| R0 | Vector number |
| R1 | Pointer to address of claiming routine |
| R2 | Value to be passed in R12 when the routine is called |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | Preserved |
| R2 | Preserved |
Use
The purpose of this call is to add a routine to the list of those that claim a vector.
Notes
This call adds the routine whose address is given in R1 to the list of routines claiming the vector. This becomes the first routine to be used when the vector is called.
The R2 value enables the routine to have a workspace pointer set up in R12 when it is called. If the routine using the vector is in a module (as will often be the case), this pointer will usually be the same as its module workspace pointer.
This call provides the same functionality of asOS_Claim, except that this call does not remove earlier identical instances (i.e. those which have identical workspace and code addresses).
See also
Social
and
ROOL Store
Buy RISC OS Open merchandise here, including SD cards for Raspberry Pi and more.