OXYGENHUB
◆ main openmsx / share / scripts / _vdp_access_test.tcl
3.3 KiB · Tcl · last changed chore(): initial commit 1 month ago source blame history raw
1 
namespace eval vdp_access_test {
2
3 
# you can tweak these to test for other stuff
4 
# TODO: make this flexible so the timing can be specified for each combination
5 
# of ports and read/write
6 
variable ioports {0x98 0x99}
7 
variable cycle_max 29
8 
# if you set this to true, you can also see OK I/O, but there are many of those!
9 
variable debug false
10 
# if you set this to true, openMSX will break when too fast access happens, so
11 
# you can investigate what's going on with the debug commands (or debugger)
12 
variable enable_break false
13
14 
variable last_access_time 0
15 
variable last_access_type
16 
variable last_access_port
17 
variable is_enabled false
18 
variable watchpoint_write_id
19 
variable watchpoint_read_id
20 
variable address_list
21
22 
set_help_text toggle_vdp_access_test \
23 
"Report in the console when VDP I/O is done which could possibly cause data
24 
corruption on the slowest VDP (TMS99xx), i.e. when time between successive I/O
25 
was less than $cycle_max cycles and display was active. Note: this script is
26 
not 100% accurate! Keep testing on a real MSX as well. The script has some
27 
tuning options; edit the script to do so, it's explained at the top what can be
28 
tuned."
29
30 
proc check_time {access_type} {
31 
	variable last_access_time
32 
	variable last_access_type
33 
	variable last_access_port
34 
	variable cycle_max
35 
	variable debug
36 
	variable enable_break
37 
	variable address_list
38
39 
	set port [expr {$::wp_last_address & 255}]
40 
	set current_time [machine_info time]
41 
	set cycles [expr {round(3579545 * ($current_time - $last_access_time))}]
42 
	set screen_enabled [expr {[debug read "VDP regs" 1] & 64}]
43 
	set vblank [expr {[debug read "VDP status regs" 2] & 64}]
44 
	set pc [format "%04x" [reg PC]]
45 
	if {($cycles < $cycle_max) && $screen_enabled && !$vblank} {
46 
		if {$pc ni $address_list} {
47 
			set valuetext ""
48 
			if {$access_type eq "write"} {
49 
				set valuetext [format " (value 0x%02X)" $::wp_last_value]
50 
			}
51 
			puts [format "VDP $last_access_type on port 0x%02X followed by a $access_type${valuetext} on port 0x%02X on address $pc and time $current_time with too few cycles in between: $cycles (< $cycle_max)" $last_access_port $port]
52 
			lappend address_list $pc
53 
			set address_list [lsort $address_list]
54 
			puts "Sorted list of addresses where too fast I/O is done: $address_list"
55 
			if {$enable_break} {
56 
				debug break
57 
			}
58 
		}
59 
	} else {
60 
		if {$debug} {
61 
			if {!$screen_enabled} {
62 
				set reason "screen is disabled"
63 
			} elseif {$vblank} {
64 
				set reason "in vblank"
65 
			} else {
66 
				set reason "last access was $cycles cycles ago, >= $cycle_max"
67 
			}
68 
			puts [format "VDP I/O $access_type to port 0x%02X OK on address: 0x$pc, $reason" $port]
69 
		}
70 
	}
71 
	set last_access_time $current_time
72 
	set last_access_port $port
73 
	set last_access_type $access_type
74 
}
75
76 
proc toggle_vdp_access_test {} {
77 
	variable is_enabled
78 
	variable watchpoint_write_id
79 
	variable watchpoint_read_id
80 
	variable address_list
81 
	variable ioports
82
83 
	if {!$is_enabled} {
84 
		set watchpoint_write_id [debug set_watchpoint write_io $ioports {} {vdp_access_test::check_time "write"}]
85 
		set watchpoint_read_id  [debug set_watchpoint read_io  $ioports {} {vdp_access_test::check_time "read"}]
86 
		set is_enabled true
87 
		set address_list [list]
88 
	} else {
89 
		debug remove_watchpoint $watchpoint_write_id
90 
		debug remove_watchpoint $watchpoint_read_id
91 
		set is_enabled false
92 
	}
93 
}
94
95 
namespace export toggle_vdp_access_test
96
97 
} ;# namespace vdp_access_test
98
99 
namespace import vdp_access_test::*