h6. [[OS_DynamicArea]] h6(. » OS_DynamicArea 24 h2. OS_DynamicArea 24 h5. (SWI &66) |_<^{width:3em}. Entry | | |<^. R0 |<^. 24 (reason code) | |<^. R1 |<^. [[Dynamic Area Numbers|Area number]] | |_<^{width:3em}. Exit | | |<^. R0 |<^. Preserved | |<^. R1 |<^. Preserved | |<^. R2 |<^. Current logical size of area, in bytes | |<^. R3 |<^. Base logical address of area | |<^. R4 |<^. [[Dynamic Area Flags|Area flags]] | |<^. R5 |<^. Maximum logical size of area, in bytes | |<^. R6 |<^. Current physical size of area, in pages | |<^. R7 |<^. Maximum physical size of area, in pages | |<^. R8 |<^. Pointer to name of area | h4. Use The purpose of this call is to return information relating to a dynamic area. Where possible this call should be preferred over the older [[OS_DynamicArea 2]], as it is able to correctly report the physical and logical sizes of [[Physical Memory Pool]] dynamic areas. h4. Notes For doubly-mapped areas, R3 on exit from this call returns the address of the boundary between the first and second copies of the area, whereas [[OS_ReadDynamicArea]] returns the start address of the first copy (i.e. the lowest valid address in the area). For sparse and PMP DAs, the current logical size is calculated from the number of pages that are currently mapped in. Therefore it is not guaranteed to describe the logical extent of the area. For non-PMP DAs, the physical size values returned in R6 and R7 will be derived from the logical size values. Unlike [[OS_DynamicArea 2]], this call cannot be used to read the handler address and parameter. h4. See also * [[Dynamic Area Flags]] * [[Dynamic Area Handler Code]] * [[OS_DynamicArea]] * [[OS_DynamicArea 2]] * [[OS_DynamicArea 8]] * [[Sparse Dynamic Areas]] * [[Physical Memory Pool]]