l65/asm.lua

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) bitzab(function(_o) return _o+( 0x1ff4+i) end) end
-- create bank stubs
for bi=0,7,1 do
    local o=(bi<<12)
    _ENV['bank' .. bi] = location{0x8000+o, 0x8fff+o, rorg=0xf000}
    local start=section{"entry"..bi, org=0x8fee+o} switchbank(0) if bi==0 then jmpabs(function(_o) return _o+( main) end) end
    section{"switchtab"..bi, org=0x8ff4+o} byte(0,0,0,0,0,0,0,0)
    section{"vectors"..bi, org=0x8ffc+o} word(start,start)
end

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

if toto ~= 15 then end

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

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

;
lda = 5 if lda < 6 then sta=7 end
;

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

section("data")
    do crosspage()
        byte(1, 2) byte(3, 4) endpage()
    end
    word(0xf080) byte(16, 3, 4, 5, 6,
        24, 32)
    word(message2)
    byte_lo(message) byte_hi(message)
    byte(function() return message&0xff end, function() return message>>8 end)

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

section("main")
    ldaimm (function(_o) return _o+(0) end)

--section{ "toto", align = 256, offset = 16 }
--section{ "toto", org = 0xf100 }
--section "waitForIntim"
section("waitForIntim") --alt short syntax when no other option
    -- n_{ a=INTIM } ?
    --lda(INTIM) -- or a=INTIM
    --bne "waitForIntim"
    ldximm (function(_o) return _o+(0xf0) end)
    ldximm (function(_o) return _o+(13) end)
    ldyimm (function(_o) return _o+(0xAB - 16 + 27 & 3 | 6 ~ 0xf >> ~3 << 1 // 5) end)
    ldximm (function(_o) return _o+(15) end,3)

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

    ldazab(function(_o) return _o+( data) end)
    ldazab(function(_o) return _o+( data) end,5)
    ldazax(function(_o) return _o+( data) end,5)
    ldaaby(function(_o) return _o+( data) end,5)
    ldazab(function(_o) return _o+( data+3) end,12)
    ldazax(function(_o) return _o+( data+3) end,12)
    ldaaby(function(_o) return _o+( data+3) end,12)
    ldainx (function(_o) return _o+(VBLANK) end,5)
    ldainx (function(a) return a+2 end,VBLANK)
    ldainy (function(_o) return _o+(VBLANK) end,5)
    ldainy (function(a) return a&3 end,VBLANK)
    jmpind (function(_o) return _o+(VBLANK) end)
    jmpind (function(_o) return _o+(VBLANK) end,12)
    jmpind (function(_o) return _o+(VBLANK-4) end)

    -- 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
    ldazab( function(c) return 0xffff&(data * c) end, v)
    ldazab( function(c) return (data*c)&0xffff end, v)
    local f = function(c) return (data*c)&0xffff end v=5 ldazab(f,v) v=3 ldazab(f,v)
    local g = function() return function(c) return (data * c)&0xffff end end

    ldazab(g(),v)
    ldazab( f,v)
    ldazax (function(_o) return _o+(_toto+15) end,16)
    ldaimm (15)

    do samepage()
        ldaimm (function(_o) return _o+(0xac) end)
        ldaimm (function(_o) return _o+(VBLANK) end)
        ldazab(function(_o) return _o+( 0xbeef) end)
        ldazab(function(_o) return _o+( VBLANK) end)
        ldaabs(function(_o) return _o+( VBLANK) end)
        ldazax(function(_o) return _o+( VBLANK) end)
        ldaaby(function(_o) return _o+( VBLANK) end)
        ldainx (function(_o) return _o+(VBLANK) end)
        ldainy (function(_o) return _o+(VBLANK) end) endpage()
    end

    beqrel( "_toto")
    aslimp()
    aslzab(function(_o) return _o+( VBLANK) end)
    aslimp()
label("_toto")
    bnerel( "_toto")
    bnerel( "waitForIntim")
    f=function() return "_toto" end bnerel( f())
    bnerel( "_toto")

    jamimp() aslimp() lsrimp() ldximm (function(_o) return _o+(16) end) ldyzab(function(_o) return _o+( 0xf0f0) end)
    rtsimp()

local filename=string.match(arg[0], ".-([^\\/]-)%.?[^%.\\/]*$")
writebin(filename..'.bin')
writesym(filename..'.sym')
print(getstats())

--[[
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" }

]]