[PicForth] Re: A smarter disassembly utility

[David McNab]

Samuel Tardieu wrote:
> David, how do this compare to PicForth integrated disassembler?

I never knew PicForth had an integrated disassembler.

But sure enough, on grepping the picforth dir for 'disass', I found 
mention of the word 'dis' in changes.html.

Wish I'd known of it before.

Samuel, you've got one real gem in PicForth!

(I'm in the process of porting my PIC C projects to PicForth, which one 
could argue is the strongest possible compliment in action)

However, PicForth suffers somewhat from incomplete doco. The existing 
doco is good, but desperately needs fleshing out, especially in regard 
to some of the internals which benefit users. I've sprained my brain 
many times trying to figure out some of the internals.

I guess the difference with picforth's 'dis' and my 'fdasm' is that 
fdasm works from outside the picforth environment, by parsing hex files 
and map files.

fdasm's output can easily be redirected to a file or pager (easy in 
unix, not sure how to redirect stdout from within gforth).

another intended use of my util is for autopsies - where one rips the 
image from a PIC back to a .hex file, and analyses what's actually 
inside the PIC's program/data memory.

Cheers
David

> 
> Here is an example of PicForth disassembly (excerpt from
> i2cloader.fs):
> 
>         ; name: add-to-buffer
>         ; max return-stack depth: 1
> 0x0661  0823    movf    0x23,w
> 0x0662  0384    decf    0x04,f
> 0x0663  0080    movwf   0x00
> 0x0664  2604    call    0x604   ; any-!
> 0x0665  0AA3    incf    0x23,f
> 0x0666  0008    return  
>         ; name: reset-i2c-buffer
>         ; max return-stack depth: 0
> 0x0667  3025    movlw   0x25
> 0x0668  00A3    movwf   0x23
> 0x0669  0008    return  
>         ; name: read-eeprom-data
>         ; max return-stack depth: 2
> 0x066A  2667    call    0x667   ; reset-i2c-buffer
> 0x066B  0826    movf    0x26,w
> 0x066C  00C5    movwf   0x45
> 0x066D  3010    movlw   0x10
> 0x066E  00C6    movwf   0x46
> 0x066F  0845    movf    0x45,w
> 0x0670  261E    call    0x61E   ; ee@
> 0x0671  2661    call    0x661   ; add-to-buffer (rs depth: 1)
> 0x0672  0AC5    incf    0x45,f
> 0x0673  0BC6    decfsz  0x46,f
> 0x0674  2E6F    goto    0x66F   ; read-eeprom-data + 0x005
> 0x0675  3020    movlw   0x20
> 0x0676  0685    xorwf   0x05,f
> 0x0677  0008    return  
> 
>   Sam

-- 
Cheers
David