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cc65/libsrc/common/zerobss.s

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This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
;
Move initialization code into the init segment git-svn-id: svn://svn.cc65.org/cc65/trunk@3404 b7a2c559-68d2-44c3-8de9-860c34a00d81
2005-02-26 09:06:46 +00:00
; Ullrich von Bassewitz, 1998-09-17, 2005-02-26.
This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
;
; Zero the bss segment.
;
Removed (pretty inconsistently used) tab chars from source code base.
2013-05-09 11:56:54 +00:00
.export zerobss
.import __BSS_RUN__, __BSS_SIZE__
.importzp ptr1
This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
Changed run location of INIT segment. So far the INIT segment was run from the later heap+stack. Now the INIT segment is run from the later BSS. The background is that so far the INIT segment was pretty small (from $80 to $180 bytes). But upcoming changes will increase the INIT segment in certain scenarios up to ~ $1000 bytes. So programs with very limited heap+stack might just not been able to move the INIT segment to its run location. But moving the INIT segment to the later BSS allows it to occupy the later BSS+heap+stack. In order to allow that the constructors are _NOT_ allowed anymore to access the BSS. Rather they must use the DATA segment or the new INITBSS segment. The latter isn't cleared at any point so the constructors may use it to expose values to the main program. However they must make sure to always write the values as they are not pre-initialized.
2015-10-14 20:52:09 +00:00
.code
This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
zerobss:
Removed (pretty inconsistently used) tab chars from source code base.
2013-05-09 11:56:54 +00:00
lda #<__BSS_RUN__
sta ptr1
lda #>__BSS_RUN__
sta ptr1+1
lda #0
tay
This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
; Clear full pages
Removed (pretty inconsistently used) tab chars from source code base.
2013-05-09 11:56:54 +00:00
L1: ldx #>__BSS_SIZE__
beq L3
L2: sta (ptr1),y
iny
bne L2
inc ptr1+1
dex
bne L2
This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
; Clear remaining page (y is zero on entry)
Removed (pretty inconsistently used) tab chars from source code base.
2013-05-09 11:56:54 +00:00
L3: cpy #<__BSS_SIZE__
beq L4
sta (ptr1),y
iny
bne L3
This commit was generated by cvs2svn to compensate for changes in r2, which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00
; Done
Removed (pretty inconsistently used) tab chars from source code base.
2013-05-09 11:56:54 +00:00
L4: rts
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