...
| Code Block | ||
|---|---|---|
| ||
IN:
A = memory mask arguments (several arguments OR'ed together):
Destination segment (allocated memory addressed for segment):
MM_S0 ($00), segment 0
MM_S1 ($40), segment 1
MM_S2 ($80), segment 2
MM_S3 ($C0), segment 3
Source of memory (to be allocated):
MM_FIX ($02), fixed workspace (not subject to swapping)
or
MM_SLT ($04), explicit slot usage, mask also following:
MC_CI ($10), internal memory
MC_C1 ($01), card 1
MC_C2 ($02), card 2
MC_C3 ($03), card 3
Allocation variations:
MM_EXC ($10), exclusive use of bank
MM_MUL ($20), use multiple banks
BCB = 0, always
C = If MM_SLT is specified, C holds bank number ($20-$ff) or slot (0-3) - otherwise 0
OUT, if call successful:
Fc = 0
IX = memory pool handle
OUT, if call failed:
Fc = 1
A = error code:
RC_NA ($06), handle not available
RC_ROOM ($07), no room
Registers changed after return:
A.FBCDEHL/..IY same
.F......./IX.. different |
...
If only destination segment is specified, you get memory from bank with
most with most free space.
OS_Mop doesn't allocate any memory, so even the very first OS_Mal can
fail can fail.
If you specified MM_MUL, you can force slot 1-3 during first
first OS_Mal by loading A with slot number.
If you didn't specify MM_MUL, all memory allocated from that pool is
guaranteed is guaranteed to be in same bank. Additionally, memory area returned from
from OS_Mal is guaranteed to be in single page.
If only the memory segment mask are specified, it is probably default'ed to MM_MUL. MM_FIX is probably an internal usage.
(TODO: explain setup for any slot any offset with OS_Mal / OS_Fma / OS_Axm)
Related calls
OS_Bix, Bind in extended address
OS_Box, restore bindings after OS_Bix
OS_Fc, select fast code (fast bank switching)
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_Mpb, set new bank binding in segment
OZ_Mgb, get current bank binding in segment
OZ_Mpb, set new bank binding in segment