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OS_DynamicArea 20 (changes)
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OS_DynamicArea
ยป OS_DynamicArea 20
OS_DynamicArea 20
(SWI &66)
| Entry | |
|---|---|
| R0 | 20 (reason code) |
| R1 | Logical address |
| Exit | |
|---|---|
| R0 | Area type: |
| 0: Dynamic Area | |
| 1: System area | |
| Other values: Reserved | |
| R1 | Area number |
Use
This call can be used to locate the dynamic area or system area that encompasses the given address.
For dynamic areas, the area number returned in R1 will be the dynamic area number. For system areas, the area number will correspond to one of the area numbers recognised by OS_Memory 16.
Notes
If the address is not located in any area then an error will be returned.
This call only checks that the address is within the minimum and maximum bounds of the area. It does not verify that there is valid memory at that address. To check that there is valid memory at an arbitrary address, use a call such as OS_Memory 24 or OS_ValidateAddress.
See also
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