-- probe_pc.lua -- sample PC/ST (IE flag) in the idle OS, and check that a
-- bpset on a sampled address actually fires.  Investigation only.
local machine = manager.machine
local cpu = machine.devices[':maincpu']
local dbg = machine.debugger
local prog = cpu.spaces['program']
if not dbg then print("ERROR: no debugger"); machine:exit(); return end
local IE = 0x200000
local START = tonumber(os.getenv("PC_START") or "3200")
local STOP  = tonumber(os.getenv("PC_STOP") or "3300")
local f = 0
local armed = false
local hist = {}
local first = {}
local rd = function(a) return prog:read_u16(a) end

emu.register_frame_done(function()
	f = f + 1
	local pc = cpu.state['PC'].value
	local st = cpu.state['ST'].value
	hist[pc] = (hist[pc] or 0) + 1
	if not first[pc] then first[pc] = f end
	if f >= START and f <= STOP and f % 10 == 0 then
		print(string.format("f%4d PC=%08X ST=%08X IE=%d DPYINT=%04X INTENB=%04X INTPEND=%04X",
			f, pc, st, (st & IE) ~= 0 and 1 or 0, rd(0xc00000a0), rd(0xc0000110), rd(0xc0000120)))
	end
	if f == START and not armed then
		armed = true
		dbg:command(string.format('bpset %08X,,{ printf "PCHIT pc=%%08X\\n", pc ; g }', pc))
		dbg:command('bpset 3F579870,,{ printf "PCHIT2 pc=%08X\\n", pc ; g }')
		print(string.format("probe_pc: bpset on sampled idle PC %08X", pc))
	end
	if f >= STOP then
		print("--- hottest PCs in window ---")
		local list = {}
		for k, c in pairs(hist) do list[#list + 1] = {k, c} end
		table.sort(list, function(a, b) return a[2] > b[2] end)
		for i = 1, math.min(10, #list) do
			print(string.format("  PC=%08X samples=%d first=%d", list[i][1], list[i][2], first[list[i][1]]))
		end
		machine:exit()
	end
end, "vt1200-probe-pc")

dbg.visible_cpu = cpu
dbg.execution_state = 'run'