GeneveOS Memory Management Functions

Memory management in MDOS is available via XOP 7.

General purpose XOPs

Return number of free pages in system

Opcode: 0

	Input	Output
R0	Opcode (0000)	Error code (always 0)
R1		Number of free pages
R2		Number of fast free pages

Claim pages into local map from free pages

Opcode: 1

	Input	Output
R0	Opcode (0001)	Error code
R1	Number of pages	Number of pages actually fetched to complete map as required
R2	Local page address	Number of fast pages fetched
R3	Speed flag (0 is slow, else fast)

Return pages into free pool from local map

Opcode: 2

	Input	Output
R0	Opcode (0002)	Error code
R1	Number of pages
R2	Local page address

Map local page at excution page

Opcode: 3

	Input	Output
R0	Opcode (0003)	Error code
R1	Local page number
R2	Execution page number

Get address map

Opcode: 4

	Input	Output
R0	Opcode (0004)	Error code
R1	Execution address	Count of pages reported
R2	Size of area for map

Declare shared pages

Opcode: 5

	Input	Output
R0	Opcode (0005)	Error code
R1	Number of pages to declare as shared
R2	Local page address
R3	Type to be assigned to shared pages

Release shared pages (type)

Opcode: 6

	Input	Output
R0	Opcode (0006)	Error code
R1	Type

Also have to check their current execution map

Get shared pages

Opcode: 7

	Input	Output
R0	Opcode (0007)	Error code
R1	Type
R2	Local page number for start of shared area

Return size of shared page group

Opcode: 8

	Input	Output
R0	Opcode (0008)	Error code
R1	Type	Number of pages in shared group

Privileged XOPs (only available for operating system)

Release task

opcode #9 : release task    in: nil        (task header at >8000)
                            out: nil

Page get

opcode #A :  page get  in:  r0=>000A
                            r1=page number to get,
                                if r1h <> 0, get first available
                            r2=speed flag   <>0 means fast
                      out:  r0=error code
                            r1=pointer to node
                            r2=page number from node

Add page to free pages in system

opcode #B : add page to free pages in system
              in:      r0=>000B
                       r1=page number
             out:      r0= error if no free nodes available

Add a node to the list of free nodes

opcode #C : add a node to the list of free nodes
              in:      r0=>000C
                       r1=pointer to node
             out:   no errors

Link a node to the specified node

opcode #D : link a node to the specified node
              in:      r0=>000D
                       r1=pointer to node
                       r2=pointer to node to link to
             out:   no errors

Get address map (system)

opcode #E, get address map  (system)
     return:           R0= count of valid pages