l65/asm.l65

dofile "vcs.lua"

TIM_OVERSCAN    = 50 -- TIM64T,  3200 cycles = ~ 42 scanlines
TIM_VBLANK      = 61 -- TIM64T,  3904 cycles = ~ 51 scanlines
TIM_KERNEL      = 17 -- T1024T, 17408 cycles = ~229 scanlines

function switchbank(i) bit 0x1ff4+i end
-- create bank stubs
for bi=0,7,1 do
    local o=(bi<<12)
    _ENV['bank' .. bi] = location(0x8000+o, 0x8fff+o)
    section{"entry"..bi, org=0x8fee+o} switchbank(0) jmp main
    section{"switchtab"..bi, org=0x8ff4+o} byte(0,0,0,0,0,0,0,0)
    section{"vectors"..bi, org=0x8ffc+o} word(0xffee,0xffee)
end

location(bank0)
--location(0xf000, 0xffff)

if toto ~= 15 then end

abc = 13 ~ 0x7
xyz = 1 << 2

x={ f=function() end }
x:f()
::lualabel::

#pragma syntax6502 off
lda = 5 if lda < 6 then sta=7 end
#pragma syntax6502 on

local function ptr_table(label, ...)
    local vals = {...}
    section{label .. "_lo", align=16} byte_lo(vals)
    section{label .. "_hi", align=16} byte_hi(vals)
end

charset(" abcdefghijklmnopqrstuvwxyz-")
@@message2 byte(4, "test", 0)
charset()
@@message byte(4, "test", 0)

@@data
    crosspage
        byte(1, 2) byte(3, 4)
    end
    word(0xf080) byte(16, 3, 4, 5, 6,
        24, 32)
    word(message2)
    byte_lo(message) byte_hi(message)
    byte(\(message&0xff), \(message>>8))

ptr_table("ptrs", message, data, 0)

@@main
    lda #0

--section{ "toto", align = 256, offset = 16 }
--section{ "toto", org = 0xf100 }
--section "waitForIntim"
@@waitForIntim --alt short syntax when no other option
    -- n_{ a=INTIM } ?
    --lda(INTIM) -- or a=INTIM
    --bne "waitForIntim"
    ldx #0xf0
    ldx #0b1101
    ldy #0xAB - 16 + 0b11011 & 3 | 6 ~ 0xf >> ~3 << 1 // 5
    ldx #15,3

    local kernel_cycles,kernel_size
    table.insert(section_current.instructions, { asbin=function() kernel_cycles=cycles kernel_size=size end })

    lda data
    lda data,5
    lda data,5,x
    lda data,5,y
    lda data+3,12
    lda data+3,12,x
    lda data+3,12,y
    lda (VBLANK,5,x)
    lda (\a(a+2),VBLANK,x)
    lda (VBLANK,5),y
    lda (\a(a&3),VBLANK),y
    jmp (VBLANK)
    jmp (VBLANK,12)
    jmp (VBLANK-4)

    -- cycles are counted without taking any branch
    table.insert(section_current.instructions, { asbin=function() print('kernel cycles: ', cycles-kernel_cycles, 'kernel size: ', size-kernel_size) end })

    v=7
    lda function(c) return 0xffff&(data * c) end, v
    lda \c((data*c)&0xffff), v
    local f = \c((data*c)&0xffff) v=5 lda !f,v v=3 lda !f,v
    local g = function() return function(c) return (data * c)&0xffff end end

    lda !g(),v
#pragma encapsulate off
    lda f,v
    lda !_toto+15,16,x
    lda #15
#pragma encapsulate on

    samepage
        lda #0xac
        lda #VBLANK
        lda 0xbeef
        lda VBLANK
        lda.w VBLANK
        lda VBLANK,x
        lda VBLANK,y
        lda (VBLANK,x)
        lda (VBLANK),y
    end

    beq _toto
    asl
    asl VBLANK
    asl
@_toto
    bne "_toto"
    bne waitForIntim
    f=\("_toto") bne f()
    bne _toto

    jam asl lsr ldx #16 ldy 0xf0f0
    rts

writebin()
writesym()

--[[
section "doOverscan"
    sta{WSYNC} -- WSYNC=a
    lda(2) sta{VBLANK} -- a=2 VBLANK=a
    lda(TIM_OVERSCAN) sta{TIM64T} -- a=TIM_OVERSCAN TIM64T=a
    jsr "waitForIntim"

section "doVBlank"
    lda(0x0e)
  label ".vsyncLoop" 
    sta{WSYNC}
    sta{VSYNC}
    lsr()
    bne ".vsyncLoop"
    lda(2)
    sta{VBLANK}
    lda(TIM_VBLANK)
    sta{TIM64T}
    jsr "waitForIntim"

section "doKernel"
    lda(TIM_KERNEL)
    sta{T1024T}
    jsr "waitForIntim"

section "start"
    -- clear zeropage
    cld()
    ldx(0)
    txa()
  label ".clearLoop"
    dex()
    tsx()
    pha()
    bne ".clearLoop"
    -- main
  label "mainLoop"
    jsr "doOverscan"
    jsr "doVBlank"
    jsr "doKernel"
    jmp "mainLoop"

section{ name="vectors", org=0xfffc }
    word{ "start", "start" }

]]