Transferability of programs
Since large programs are not kept
on some JR, yes and, moreover, have re
variables, then tell you how to make a big
relocatable program. For example, it is at
changes to program the cache: one
the same fragment works in one case
in Cache, and in another - in the ordinary RAM.
1. With the creation of tables in the semi-manual mode
Applies, for example, in Pro Tracker'e
when compiling the music player. PT storage
nit player, originally otassemblirovanny
at # c000. To make it work
tal to the right address, the contents of some
its cells (which refer to the address
procedures and variables) pereschityvayutsya.Ad
rez themselves are calculated cells are stored
in a special table. More precisely, instead of Adre
owls kept there distance from the previous
ing cells are calculated to the next
(So decided to save the first author of Pro
Tracker'a, because the table is constantly
lies in the memory).
LD A, (SNGST +1); A = high byte,
; Address to which we
; Compile player
LD IX, TRELOC; address table
; Displacement (relocation)
LD HL, plaer; where the player is
LD D, # C0; byte address to
, Which last time
; Compiled Player
LD ($ -1), A
LD E, A
LD B, L
REL0 LD C, (IX)
LD A, C
AND A
RET Z; code 0 - end of the table
INC IX
ADD HL, BC
INC A
JR Z, REL0; code 255
LD A, (HL)
SUB D
ADD A, E
LD (HL), A
JR REL0
Code 255, as we see, particularly - he misses
255 bytes, if the cell to the next higher
255 bytes (not exactly 255 bytes).
Relocation table compiled by
comparison of two player options: one
compiled under # c000, and the other - under the
# C100. Here sravnivalka:
ORG # A000
P1 INCBIN "PLYC0"; player,
, Compiled by # C000
E1
ORG # C100
P2 INCLUDE "playFAST", # C4; same
; Player, will be
; Compiled under # C100
module; module address = address end player.
, Then the module address in this instance
; Player will be moved to # 100 bytes
, Compared with an instance of "PLYC0"
ORG # 6000
LD IX, TAB
LD HL, P1
LD DE, P2
LD C, 0
CP0 LD A, (DE)
SUB (HL)
JR Z, CPOK; bytes differ?
DEC A; bytes differ by 1?
JR NZ, ERR; NO ???-> out by mistake
LD (IX), C
INC IX
LD C, 0
CPOK INC HL
INC DE
INC C
JR NZ, CPNOFF
LD (IX), 255
INC IX
LD C, 1
CPNOFF LD A, L
CP E1
JR NZ, CP0
LD A, H
CP 'E1
JR NZ, CP0
LD (IX), 0
INC IX
RET
; Out by mistake: we slipped significantly
; Different files players
ERR LD HL, 0
LD DE, # 5800
LD BC, 768
LDIR
RET
TAB = # 7000
The procedure should be run from the STS. Address
end of the table will see the register IX.
2. With the creation of tables automatically
In PT Util for compiling the table when
changes more convenient method, in which
assemble necessary not 2-3, but only
1. Here's how.
Player for PT Util sits in a separate
source code, which when it INCLUDE'inge
main program is assembled as Oba
esidual player. But if his attempt Otas
semblirovat as an independent program
Therefore, we:
1. Avtoopredelyaetsya: address compilation pa
Veins # 8000, therefore, need to make
compilation to create peremeschalnoy Table
Litsa.
2. Player is assembled as a macro
MACRO pp
(All completely driven into the macro), PA
mashing is not placed. (The same occurs
leads and referred INCLUDE'inge.)
3. Macro player assembled on-us
toyaschemu with local labels, under the address
# 8000. (But this is not at INCLUDE'inge
occurs.)
4. Macro player assembled on-us
toyaschemu again, not with the local label
mi, under the address # C000. (And if INCLUDE'inge -
under an address that was current at the time
Team INCLUDE.)
5. Sravnivalka assembled. Address for
start-up programs - go to sravnivalku.
Ie: run on RUN - compiled
table. You can save it manually. Later
I learned protsedurku SAVEOBJ, it is the month
then apply here - then on the RUN table
not only the composition but also to continue. AND
if all - the table is already possible to use
in the main program by INCBIN. In about
cedure SAVEOBJ piece of initialization
program (more precisely, of implied
as such - for example, from our sravnivalki)
You can go through JP nenado. I mean
my version SAVEOBJ, rather than the one distributed Capry.
3. Through macros j, c, l
In ZXRar I realized even more convenient
way: the table movement is based directly
at the stage of assembling the main program
We, ourselves alasmom. However, no INCBIN
do not need.
For such a method is required to determine
following macros:
MACRO rg
CurCa = $
ORG RelCa
DW CurCa +
RelCa = $
ORG CurCa
ENDM
MACRO j
2 rg
IFN? J1-2, there is the 2 nd option
; Macro?
JP
, 1, if there is, such a JP
ELSE
JP
And if not, then edakii
ENDIF
ENDM
MACRO c
2 rg
IFN? J1-2
CALL
1
ELSE
CALL
ENDIF
ENDM
MACRO l
LD
1
rg 0-1; just -1 in the old alasmah
And it was impossible, since in a macro
; Rg would be obtained CurCa + -1.
; In the new can.
ENDM
And they are used in movable fragments
those commands instead of JP [cc,] nn, CALL [cc,] nn,
LD (...), rp, LD rp ,(...).
But you first need to specify the starting address,
from which to build the table:
RelCa = # C000
As we see here each relotsiruemy
address has 2 bytes in the table (and not
1, as was the Pro Tracker'e). Here savings
memory to anything - because you need a table
lko at the launch stage ZXRar'a.
Here's the place the initialization procedure in
ZXRar, which is responsible for throwing
moved fragment ZXRar in the cache (before
preliminarily find out whether the computer
cache):
DI
IN A, (# FB)
LD H, 0
LD A, (HL)
INC (HL)
CP (HL)
JR Z, ncach
LD HL, End; here lies the table.
; Relocation.
; Why here - see below!
LD B, RelSz; length of the table. relocation.
; How it feels - see below
Rel0 LD E, (HL)
INC HL
LD D, (HL)
INC HL
LD A, (DE)
SUB 'cachecode
LD (DE), A
DJNZ Rel0
LD HL, cachecode
LD D, B, E, L; low byte address
, Not me, but the senior will be 0
LD B, 'cachelen +1; instead
; LD BC, cachelen
; (Win = 1 byte)
LDIR
ncach
Before autobuild ZXRar'a table Reuleaux
cation must, of course, throw in the tail
program to get a code
block. Here's how to do drawn after
dnie line source code ZXRar'a:
DISPLAY "reloc tab end =", RelCa
End = end
RelSz = RelCa-# C000 / 2
end = RelSz * 2 + end
INCLUDE "mrip *", # C0; avtosborschik
; (See IG # 5)
ORG $
LD HL, # C000
LD DE, End
LD BC, RelSz * 2
LDIR
JP nenado
With nenado the same focus that was the case
SAVEOBJ. This transition to sohranyalku (if
withheld Caps Shift) or launch prog
FRAMEWORK at GO (If Caps Shift otpu
Puppy).
A. Coder
