-- code22_probe.lua
--
-- Resolve two mechanics at the level-1 error dispatcher:
--   (1) does a bpset fire BEFORE or AFTER its instruction executes?
--   (2) what 32-bit value does the dispatcher read from *a13(0xffe0)?
--
-- We break at 0x3FDF0630 (the read) and at 0x3FDF0650 (the next instruction,
-- jreq) and print a8 / a13 / the dword at the read address.
--
--   CP_FRAMES=300 <mame> vt1200 ... -autoboot_script harness/mame/code22_probe.lua

local machine = manager.machine
local cpu = machine.devices[':maincpu']
local dbg = machine.debugger
if not dbg then print("ERROR: no debugger"); machine:exit(); return end

dbg:command('bpset 3fdf0630,,{ printf "AT-READ  pc=%08X a13=%08X a14=%08X a8=%08X d@16F0=%08X\\n", pc, a13, a14, a8, d@16F0 ; g }')
dbg:command('bpset 3fdf0650,,{ printf "AT-NEXT  pc=%08X a8=%08X d@16F0=%08X\\n", pc, a8, d@16F0 ; g }')
print("breakpoints armed")

local maxframes = tonumber(os.getenv("CP_FRAMES") or "300")
local n = 0
emu.register_frame_done(function()
	n = n + 1
	if n >= maxframes then
		print("done (" .. n .. " frames)")
		machine:exit()
	end
end, "vt1200-cp")

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