On Sat, 9 Aug 2003 06:20:20 EDT, [EMAIL PROTECTED] wrote:
> Hmm - one of my old machine code extensions reports an error on QL2K (oddly
> enough, it reports Channel Not Open when I use d$=SAV_DEV$).
>
> Can anyone spot anything wrong with the code - I wonder if I have cocked up
> the return stack...
>
> Sorry about the mess - I cannot find the original assembler, so had to use
> DEA to get the source back...
>
> * Start of Deassembly Code - Dea v5.2 Plus 3
> * Original file: WIN2_NEMESIS_HDEV_cde
> * Code execution starts at $10000 with label Lab10000
>
> START_CODE
> Lab10000 lea lab1000a,a1
> movea.w $0110,a0 ; SB.INIPR
> jmp (a0)
>
> * Def SB extensions
> Lab1000A dc.w 0
> dc.w 0
> dc.w 2
> dc.w lab1001e-*
> dc.b 8
> dc.b 'SAV_DEV$'
> dc.b 0
> dc.w 0
> * End SB ext
That last 'dc.b 0' should be removed, although it will not make a
difference here given their is no more function name after that one
and that the following bytes are 0 as well...
The number of bytes in the name table must be kept even: as
SAV_DEV$ counts 8 bytes, you don't need for a padding null byte.
> Lab1001E moveq #0,d1
> moveq #0,d0
> move.w lab10076,d1
> beq lab1006a
> btst #0,d1
> beq.s lab10032
> addq.l #1,d1
> Lab10032 addq.l #2,d1
> move.l d1,d5
> movea.l $58(a6),a1
> movea.w $011a,a0 ; QA.RESRI
> jsr (a0)
> movea.l $58(a6),a1
> suba.l d5,a1
> move.l a1,$58(a6)
> movea.l a1,a2
> lea lab10076,a0
> moveq #0,d0
> move.w (a0)+,d0
> move.w d0,0(a6,a2.l)
> subq.l #1,d0
> Lab1005A move.b (a0)+,2(a6,a2.l)
> addq.l #1,a2
> dbf d0,lab1005a
> moveq #1,d4
> moveq #0,d0
> rts
>
> Lab1006A moveq #-$0c,d0 ; ERR.INAM
> rts
>
> Lab1006E dc.l '<<QDRV>>'
>
> Lab10076 dc.w 13
> dc.b 'win2_NEMESIS_'
>
> Lab10085 dc.b 0
> Lab10086 ds.b 34
> END_CODE
> end
> * End of Deasm
The code seems correct although far than optimized. I'd propose:
Lab1001E moveq #0,d5 Clear MS word.
lea Lab10076,a4 Name string address
move.w (a2)+,d5 Name length
addq.l #3,d5 | Take length word into account
bclr #0,d5 | and round up to word boundary
move.l d5,d1 Number of bytes to reserve
movea.l $58(a6),a1 Arithmetic stack address.
movea.w $011a,a0 QA.RESRI
jsr (a0) Reserve the space on the stack
movea.l $58(a6),a1 New stack address
suba.l d5,a1 Make space for the string
move.l a1,$58(a6) Store the new top of stack
movea.l a1,a2 Copy of stack pointer
lsr.l #1,d5 | Number of words to transfer
subq.l #1,d5 |
Lab1005A move.w (a4)+,0(a6,a2.l) Transfer a word.
addq.l #2,a2 Increment stack pointer
dbf d5,Lab1005A Continue until end of name.
moveq #1,d4 Parameter on stack = string
moveq #0,d0 No error
rts retuns...
Lab1006E dc.b '<<QDRV>>'
Lab10076 dc.w 13
dc.b 'win2_NEMESIS_'
Lab10086 ds.b 35
The above is tested and working.
QDOS/SMS forever !
Thierry ([EMAIL PROTECTED]).
