Added screen initialization on Apple GEOS.

git-svn-id: svn://svn.cc65.org/cc65/trunk@5568 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/geos-common/system/crt0.s b/libsrc/geos-common/system/crt0.s
index df4e9d8f90f17162d2a13729c5aef734bccae82a..8dba46f6d5a839d2fa7e69cc2cadbbb880dd5aa4 100644 (file)
--- a/libsrc/geos-common/system/crt0.s
+++ b/libsrc/geos-common/system/crt0.s
@@ -5,43 +5,63 @@
 ; 26.10.99, 10.3.2000, 15.8.2001, 23.12.2002
 
            .export _exit
-            .export __STARTUP__ : absolute = 1         ; Mark as startup
+           .export __STARTUP__ : absolute = 1          ; Mark as startup
            .import __VLIR0_START__, __VLIR0_SIZE__     ; Linker generated
-           .import __STACKSIZE__                       ; Linker generated
+           .import __STACKSIZE__, __BACKBUFSIZE__      ; Linker generated
            .import initlib, donelib
            .import callmain
            .import zerobss
            .importzp sp
 
            .include "jumptab.inc"
+           .include "geossym.inc"
+           .include "const.inc"
 
 ; ------------------------------------------------------------------------
 ; Place the startup code in a special segment.
 
 .segment       "STARTUP"
 
-; Clear the BSS data
+; GEOS 64/128 initializes the screen before starting an application while
+; Apple GEOS does not. In order to provide identical startup conditions
+; we initialize the screen here on Apple GEOS. For the same reason we set
+; the pattern and dispBufferOn even on GEOS 64/128 although we don't use
+; them here.
+
+       lda #2                  ; Checkerboard pattern
+       jsr SetPattern
+       lda #<(ST_WR_FORE | .MIN (ST_WR_BACK, __BACKBUFSIZE__))
+       sta dispBufferOn
+.ifdef __GEOS_APPLE__
+       jsr i_Rectangle
+       .byte 0
+       .byte SC_PIX_HEIGHT-1
+       .word 0
+       .word SC_PIX_WIDTH-1
+.endif
+
+; Clear the BSS data.
 
        jsr zerobss
 
-; Setup stack
+; Setup stack.
 
        lda #<(__VLIR0_START__ + __VLIR0_SIZE__ + __STACKSIZE__)
+       ldx #>(__VLIR0_START__ + __VLIR0_SIZE__ + __STACKSIZE__)
        sta sp
-       lda #>(__VLIR0_START__ + __VLIR0_SIZE__ + __STACKSIZE__)
-               sta sp+1                ; Set argument stack ptr
+       stx sp+1
 
-; Call module constructors
+; Call module constructors.
 
        jsr initlib
 
-; Push arguments and call main()
+; Push arguments and call main().
 
        cli
-               jsr callmain
+       jsr callmain
 
 ; Call module destructors.
 
-_exit: jsr donelib             ; Run module destructors
+_exit: jsr donelib
 
-       jmp EnterDeskTop        ; return control to the system
+       jmp EnterDeskTop        ; Return control to the system