Register parameters
| Code Block | ||||
|---|---|---|---|---|
| ||||
IN:
A7IX = evenmemory bankhandle needed (forfrom segment 0 allocationprevious OS_Mop)
A6B = fixedbank memory requested (no subject to swappingslot ORed)
A5H = frompage anyaddress slothigh A0-A1 = slot number if A5=0
H = page offset byte ($00-$3F)
L = number of pages to be wantedallocated (1 to 64)
OUT: Fc = 0 if empty, memory foundhas atbeen bankallocated
B Fc = 1, A = RC_Room if not enough space in slot(s)
A = RC_Fail if bad argument
Registers changed after return:
..BCDE..DE..L/IXIY same
AFBCAF....H.HL/.... different |
Notes
This call tells application in which bank the memory area requested is free for allocationallocates a large contiguous memory area at explicit address. Refer to explicit memory allocation for further informationsinformation. This system call is only available in OZ release V4.6 and newer.
Related calls
...
This call does not return H modified for OS_Mop MM_Sx segment. The caller must preserve/restore H after call, then perform segment adjustment, for example:
| Code Block | ||
|---|---|---|
| ||
...
ld h,0 ; any bank offset
ld l,b ; B pages requested
ld a, FM_FIX | FM_ANY | FM_NOF ; OS_Fma allocates an address from any slot
oz OS_Fma
ret c
ld d,h
oz OS_Axm ; allocate L pages at BH00
ld h,d
ret c
res 7,h
set 6,h ; link offset to S1, where allocated memory will be bound (see below)
ld l,0 ; allocation is on page boundary
ld c,MS_S1 ; bind successfully BHL allocated memory into local S1 address space
oz OS_Mpb
... |
Applications should use OS_Mal for multiple page allocation, all convenience is provided there.
Related calls
OS_Axp, Allocate explicit page
OS_Bix, Bind in extended address
OS_Box, Restore bindings after OS_Bix
OS_Fc, Select fast code (fast bank switching)
OS_Fma, Find memory for allocation
OS_Fxm, Free explicit memory
OS_Mal, Allocate memory
OS_Mcl, Close memory (free memory pool)
OS_Mfr, Free (previously allocated block) memory
OS_Mgb, Get current bank binding in segment
OS_Mop, Open memory (allocate memory pool)
OS_Mpb, Set new bank binding in segment
OZ_Mgb, Get current bank binding in segment
OZ_Mpb, Set new bank binding in segment