illegal memory access not working

[jotd]

Hi,

Trying to debug something. wd 1 is breaking for nothing... check the current instruction, the log below, and see it's not working at all.
Tells me it's trying to write in some custom $DFFxxx register whereas it's writing to regular chipmem

My config is a 68020 no JIT 24 bit addressing (CD32 with hard disk actually)



thx

[Toni Wilen]

Since memwatch breakpoint handling was changed (few releases ago), wd only sees accesses that also hit any memwatch region.

Use something like "w 0 <start> <len> none" or similar.

[jotd]

yes, it works. It's more powerful, but also less convenient. Well, I found something fishy thanks to it!!

[ross]

Sorry to revive this old thread, but I've the same mentioned problem.

Latest WinUAE stable, no JIT or fancy configuration, a simple A500 or A1200 quick config, CE (or any other similar one).

Tried with "w 0 <start> <len> none" or similar.
But

wd

does't trap or log illegal memory access.


And write strangeness:

>wd
Memwatch breakpoints enabled
Illegal memory access logging enabled. Break=0
>

or

>wd 1
Cleared logging addresses 00000001 - 00000002
>

What's the way to make it work?

I've also problem with

w

command and Z3 memory, but I can't understand under what conditions it doesn't work.

[Toni Wilen]

wd supports only first 16M of address space. Including Z3 space would require huge amounts of RAM.

w does not have any limits.

[ross]

Originally Posted by Toni Wilen

wd supports only first 16M of address space. Including Z3 space would require huge amounts of RAM.

w does not have any limits.

So the only possibility is to use the native MMU?

What we need is simply a log when unmapped memory is accessed.
Yes Z3 memory can be huge and problematic, but think about old games/demos/stuff where 24-bit memory is usual.
An option for a break/log if ((high byte != 0) && (24-bit memory flag)) can be simple.
And wd working in 'low' 16MB memory space.

[Toni Wilen]

Any CPU unmapped (address space where nothing is mapped) access is already logged if misc panel illegal access option is ticked.

[ross]

And obviously I've missed this option Thanks.
I suppose all zone mapped as <none> in current address space map trigger a log.

But how about the 'mirror' zone?
I tried wd for the addresses $80000-$1FFFFF but it didn't seem to work, nor in $C00000 and up
(off course not used in memory map).

[Rock'n Roll]

ok, some points to this command:

wd [<0-1>] Enable illegal access logger. 1 = enable break.

I don't know why this command get the name 'wd'? Maybe better would be: 'im' illegal memory (access)
And then wd would be free as command for delete all memory watchpoints similar to fd command.

Then what's the logic behind 'wd'?

>wd
Illegal memory access logging disabled
>wd 0
Illegal memory access logging enabled. Break=1
>wd 0
Cleared logging addresses 00000000 - 00000001
>wd 1
Cleared logging addresses 00000001 - 00000002
>wd
Illegal memory access logging disabled
>wd 1
Illegal memory access logging enabled. Break=1
>wd 1
Cleared logging addresses 00000001 - 00000002
>wd 0
Cleared logging addresses 00000000 - 00000001
>wd
Illegal memory access logging disabled
>wd 0
Illegal memory access logging enabled. Break=1
>wd 30000
Cleared logging addresses 00030000 - 00030001
>wd 30000 40000
Cleared logging addresses 00030000 - 00070000
>

Maybe better would be: wd enable/disable illegal access logger (or even better 'im')
>wd
Illegal memory access logging enabled
>wd
Illegal memory access logging disabled

Like 'smc', the 'wd' needs a dummy memwatch
>w 0 $0 $1000000 none ; w 0 <start> <len> none
0: 00000000 - 00FFFFFF (16777216) RWI NONE ; it's need for wd (max. 16MB)

Is it possible to set this memwatch automatically as default and to give out the actual setting info by wd enabling?

>wd
Illegal memory access logging enabled
0: 00000000 - 00FFFFFF (16777216) RWI NONE ; default complete 16M

Then wd in practice:

	move.b d0,$F80000	; write access ROM - illegal memory access
	move.w d0,$F90000	; write access ROM - illegal memory access
	move.l d0,$FA0000	; write access ROM - illegal memory access
	move.w $dff180,d1	; Color00, data access custom-chips	(write only)
	move.w d0,$200002	; 8MB Fast RAM area
	move.w #$0,$C80000	; normaly unused
	
>g
WO: 00F80000    PC=00022E3C
...
00022e3c 13c0 00f8 0000           move.b d0,$00f80000 [11]	; works fine
>g
WO: 00F90001    PC=00022E44		
WO: 00F90000    PC=00022E44
...
00022e44 33c0 00f9 0000           move.w d0,$00f90000 [6602]	; works fine
>g
WO: 00FA0001    PC=00022E4C
WO: 00FA0000    PC=00022E4C
...
00022e4c 23c0 00fa 0000           move.l d0,$00fa0000 [524151ca]	; works fine
>
;-------------------------------------------------------------
>g
RO: 00DFF181=FF PC=00023A24
RO: 00DFF180=FF PC=00023A24
...
00023a24 3239 00df f180           move.w $00dff180,d1	; works fine
...
;-------------------------------------------------------------
>g
W: 00200003=AB PC=00023F96
W: 00200002=BA PC=00023F96
...
00023f96 33c0 0020 0002           move.w d0,$00200002	; works fine
;-------------------------------------------------------------
>g
WO: 00DFF001    PC=00023FA0
WO: 00DFF000    PC=00023FA0
...
00023fa0 33fc 0000 00c8 0000      move.w #$0000,$00c80000	; works fine
00023fa8 0839 0006 00bf e001      btst.b #$0006,$00bfe001
Next PC: 00023fb0
>

info message is missed like:
illegal memory access at
WO: 00F80000 PC=00022E3C
...

Then I see a W: WO: RO:
it could be: Write, Write Only, Read Only but ROM ist for me: RO and not WO and DFF180 is WO and not RO.
W offcourse is both.

;-------------------------------------------------------------

Then some questions to the memory dump.

>dm
00000000    2048K/4 =     512K ID* C16 Chip memory
00200000    8192K/0 =    8192K --  F16 <none>
00A00000    2048K/0 =    2048K --  CIA CIA
00C00000     512K/1 =     512K ID* C16 Slow memory
00C80000    1024K/0 =    1024K --  F16 Custom chipset
00D80000     256K/0 =     256K --  C16 <none>
00DC0000      64K/0 =      64K --  C16 Battery backed up clock (MSM6242B)
00DD0000      64K/0 =      64K --  C16 <none>
00DE0000     128K/0 =     128K --  C16 Custom chipset
00E00000     512K/2 =     256K ID* F16 Kickstart ROM (C4F0F55F)
=KS ROM v1.3 (A500,A1000,A2000) rev 34.5 (256k) [315093-02]
00E80000     512K/0 =     512K --  F16 <none>
00F00000      64K/1 =      64K --* F16 UAE Boot ROM
00F10000     448K/0 =     448K --  F16 <none>
00F80000     512K/2 =     256K ID* F16 Kickstart ROM (C4F0F55F)
=KS ROM v1.3 (A500,A1000,A2000) rev 34.5 (256k) [315093-02]
>

Maybe an additional info sign about a potential 'illegal access area' W, RO, WO would be good.
(All <none> and ROM regions and the son on)

Then my interpretation to this /0 /1 /2 /4 is:
/0 - not present
/1 - 1x present
/2 - 2x present (mirrored)
/4 - 4x present (mirrored)

What means ID* or '--' or '--*' ?
I - Instruction, D - Data, * - ?

;-------------------------------------------------------------

00000000 2048K/4 = 512K ID C16 Chip memory ; Chip memory
;0800000 copy of chip
;1000000 copy of chip
;1800000 copy of chip

But there is no illegal memory access log in the mirrored chip ram area from $800000 - $1FFFFF
because wd supports only the first 16M of address space.

>w 0 $0 $1FFFFFF none
0: 00000000 - 01FFFFFE (33554431) RWI NONE ; false message?

with Paths 'Log window' enabled and Misc Panel 'Log illegal memory accesses' is ticked, the illegal memory access is logged
Illegal wput at 0088888a=1234abba PC=2464c ; works

[Toni Wilen]

Just a quick note: not interested in debugger updates at the moment, maybe (much) later.

All debugger features are "undefined". Features randomly change or appear if I need some new feature to debug something..