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Don't save and restore the zero page locations used.

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Saves 19 bytes code (in the exe file) and reduces memory footprint
of the program by 45 bytes (code & bss).
This commit is contained in:
Christian Groessler 2013-07-02 19:55:00 +02:00
parent 5edcd639e0
commit 7ebaec1802
3 changed files with 6 additions and 29 deletions
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1
cfg/atari.cfg
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@ -19,7 +19,6 @@ SEGMENTS {
CODE: load = RAM, type = ro, define = yes;
RODATA: load = RAM, type = ro;
DATA: load = RAM, type = rw;
ZPSAVE: load = RAM, type = bss, define = yes;
BSS: load = RAM, type = bss, define = yes;
ZEROPAGE: load = ZP, type = zp;
EXTZP: load = ZP, type = zp, optional = yes;

1
cfg/atarixl.cfg
View File

@ -19,7 +19,6 @@ SEGMENTS {
CODE: load = RAM, type = ro, define = yes;
RODATA: load = RAM, type = ro;
DATA: load = RAM, type = rw;
ZPSAVE: load = RAM, type = bss, define = yes;
BSS: load = RAM, type = bss, define = yes;
ZEROPAGE: load = ZP, type = zp;
EXTZP: load = ZP, type = zp, optional = yes;

33
libsrc/atari/crt0.s
View File

@ -13,7 +13,7 @@
.import initlib, donelib
.import callmain, zerobss
.import __STARTUP_LOAD__, __ZPSAVE_LOAD__
.import __STARTUP_LOAD__, __BSS_LOAD__
.import __RESERVED_MEMORY__
.include "zeropage.inc"
@ -26,7 +26,7 @@
.word $FFFF
.word __STARTUP_LOAD__
.word __ZPSAVE_LOAD__ - 1
.word __BSS_LOAD__ - 1
; ------------------------------------------------------------------------
; Actual code
@ -40,14 +40,6 @@
; Real entry point:
; Save the zero page locations we need
ldx #zpspace-1
L1: lda sp,x
sta zpsave,x
dex
bpl L1
; Clear the BSS data
jsr zerobss
@ -126,17 +118,9 @@ _exit: jsr donelib ; Run module destructors
lda appmsav+1
sta APPMHI+1
; Copy back the zero page stuff
ldx #zpspace-1
L2: lda zpsave,x
sta sp,x
dex
bpl L2
; Turn on cursor
inx
ldx #0
stx CRSINH
; Back to DOS
@ -147,12 +131,6 @@ L2: lda zpsave,x
; ------------------------------------------------------------------------
.segment "ZPSAVE"
zpsave: .res zpspace
; ------------------------------------------------------------------------
.bss
spsave: .res 1
@ -160,7 +138,8 @@ appmsav: .res 1
old_shflok: .res 1
old_lmargin: .res 1
.segment "AUTOSTRT"
.word RUNAD ; defined in atari.h
.segment "AUTOSTRT"
.word RUNAD ; defined in atari.inc
.word RUNAD+1
.word __STARTUP_LOAD__ + 1