pa65

Pseudo Static Heap for ca65
or
Parisoft Allocator for ca65

Quick Start

1. Download the latest version at releases page.
2. Declare all functions and variables using pa65 directives.
3. Choose a file name like pa65.inc and include it in all your source files:

   •  .include "pa65.inc"

4. Call pa65 with your source files to generate the .inc file above:

   •  java -jar pa65-xy.jar -o pa65.inc file1.s ... fileN.s

5. Just assembly/link your project as you've used to do

Directives

• .func
• .palloc
• .pfree
• .pref
• .ftable
• jtx
• jty

---

.func(name)

Declare a function with the given name.
The function must terminate with .endfunc.

Parameters

• name - The name of the function

Example

.func foo
rts
.endfunc

---

.palloc(seg,var,size)

Allocate some bytes of a variable into a segment.

Parameters

• seg - The name of a segment to allocate into. The directives .zeropage and .bss can also be used.
• var - The name of the variable
• size - The number of bytes to allocate

Example

.func foo
.palloc .zeropage, acme, 1 ; allocate 1 byte in zp for acme
; some code here
.endfunc

.palloc bar
; call foo passing the value 1 to the acme parameter
lda #1
sta foo::acme
jmp foo
.endfunc

---

.pfree(var1 ... varN)

Free the memory space allocated by some variables.

Parameters

• var1...varN - The name of the variable(s) to free

Example

.func foo
.palloc "SEG1", tmp1, 1
.palloc "SEG2", tmp2, 1
; some code here
.pfree tmp1, tmp2 ; free the space allocated by tmp1 and tmp2
.palloc "SEG1", acme, 1 ; reuse the space freed by tmp1
; some code here
.endfunc

---

.pref(v1,v2)

Create a reference of a variable defined on another function.
Useful to preset the parameters of a function.

Parameters

• v1 - The name of the referer variable
• v2 - The name of the referee variable

Example

.func foo
.palloc .zeropage, acme, 1
; some code here
.enfunc

.func bar
.pref acme, foo::acme ; make a reference of foo.acme
jsr foo ; just call foo as the parameter is alread set by the callee (baz)
; some code here
.endfunc

.func baz
; call bar passing 1 to the acme parameter
lda #1
sta bar::acme
jmp bar
.endfunc

---

.ftable(name,funcs)

Declare a table of functions. See jtx and jty.

Parameters

• name - The name of the table
• funcs - Array of functions

Example

.linecont+

.func foo
; some code here
.endfunc

.func bar
; some code here
.endfunc

.ftable choose_foo_or_bar, {\
   foo-1,\
   bar-1\
}

---

jtx table

Jump to a function referenced by a .ftable at index X using RTS trick.

Parameters

• table - The name of a function table declared as .ftable

Example

.linecont+

.func switch
.palloc .zeropage, idx, 1
ldx idx
jtx choose_foo_or_bar ; jump to foo if idx is 0; jump to bar if idx is 1
.endfunc

.func foo
; some code here
.endfunc

.func bar
; some code here
.endfunc

.ftable choose_foo_or_bar, {\
   foo-1,\
   bar-1\
}

---

jty table

Jump to a function referenced by a .ftable at index Y using RTS trick.

Parameters

• table - The name of a function table declared as .ftable

Example

.linecont+

.func switch
.palloc .zeropage, idx, 1
ldy idx
jty choose_foo_or_bar ; jump to foo if idx is 0; jump to bar if idx is 1
.endfunc

.func foo
; some code here
.endfunc

.func bar
; some code here
.endfunc

.ftable choose_foo_or_bar, {\
   foo-1,\
   bar-1\
}

---