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OS_Memory

Entry
R0	Reason code (bits 0 – 7),
R0	Flags (bits 8 – 31) which are reason code specific
All other registers are dependent on reason code

Exit
R0	Preserved
All other registers dependent on reason code

The purpose of this call is to perform various operations for memory management.

The action performed depends on the reason code value in R0.

The flags (passed by R0 on entry) are specific to each reason code.

#	Hex #	Action
0	&00	General page block operations (32 bit)
1	&01	Reserved for system use
2	&02	Reserved for system use
3	&03	Reserved for system use
4	&04	Reserved for system use
5	&05	Reserved for system use
6	&06	Read the size of the physical memory arrangement table
7	&07	Read the physical memory arrangement table
8	&08	Read the amount of a specified sort of memory available
9	&09	Read controller presence and base logical address
10	&0A	Free pool lock
11	&0B	Reserved for system use
12	&0C	Recommend page
13	&0D	Map in IO permanent
14	&0E	Map in IO temporary
15	&0F	Map out temporary IO
16	&10	Memory areas
17	&11	Memory access privileges
18	&12	Find access privilege
19	&13	Prepare for DMA
20	&14	Compatibility settings
21	&15	Map in IO permanent from 64 bit space
22	&16	Map in IO temporary from 64 bit space
23	&17	Reserve RAM pages
24	&18	Check memory access
25	&19	Read controller presence and base physical address
64	&40	General page block operations (64 bit)
65	&41	Logical to physical address translation

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RISC OS is an Open Source operating system owned by RISC OS Developments Ltd and licensed primarily under the Apache 2.0 license.