bms_create

Description

Create slots for bank memory system. Returns NULL and store error, if something is wrong, or returns struct ptr if success

Input

Accumulator : flags (eg : FLAG_PROT_READ_WRITE only supported)
Y Register : low byte of the length to allocate (0 to 7)
X Register : high byte of the length to allocate (8 to 15)
RES : 2 bytes of the length to allocate (16 to 23)

Modify

RES
TR2
libzp
libzp+2
libzp+4
libzp+5

Returns

Accumulator : the low ptr for bms struct it returns null ($00 in A and X)
X Register : the low ptr for bms struct it returns null ($00 in A and X)

Use "BMS_CREATE length0_to_15, length16_to_31, flags" macro in 'include/bms.mac'

Example

 lda #FLAG_PROT_READ_WRITE
 ldx #>15000 ; Length : 15000
 ldy #<15000
 jsr bms_create
 cmp #$00
 bne @not_null
 cpx #$00
 bne @not_null
 ; can not be allocated
 rts
@not_null:
 ...