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cc65/cfg/c64-overlay.cfg

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INI
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Adapted, to the c64 target, the INIT-segment overlay scheme from the apple2 targets. When a program starts running, INIT is moved from one place to another place. Then, INIT's code is executed; and, the first place is re-used for variables. After the INIT code has finished, the second place can be re-used by the heap and the C stack. That means that initiation code and data won't waste any RAM space after they stop being needed.
2015-10-05 09:47:43 +00:00
FEATURES {
Cleaned up C64 linker configs. The BSS segment and the ONCE segment share the same start address. So they need to be placed in two different memory areas. So far BSS was placed in the MAIN memory area and ONCE was placed in an additional memory area. Both memory areas were written to the output file. They just "happened" to be loadable and runnable at a stretch. Now ONCE is placed in the MAIN memory area and BSS is placed in an additional memory area. Only MAIN is written to the output file. It becomes more obvious that BSS is "just" defined to share memory with ONCE.
2016-03-13 13:32:07 +00:00
STARTADDRESS: default = $0801;
Adapted, to the c64 target, the INIT-segment overlay scheme from the apple2 targets. When a program starts running, INIT is moved from one place to another place. Then, INIT's code is executed; and, the first place is re-used for variables. After the INIT code has finished, the second place can be re-used by the heap and the C stack. That means that initiation code and data won't waste any RAM space after they stop being needed.
2015-10-05 09:47:43 +00:00
}
Added secondary linker config for C64 overlays (incl. demo program). git-svn-id: svn://svn.cc65.org/cc65/trunk@5679 b7a2c559-68d2-44c3-8de9-860c34a00d81
2012-06-03 16:16:11 +00:00
SYMBOLS {
Reduced c64-overlay.cfg's size by factoring out a different common expression.
2015-10-08 10:11:37 +00:00
__LOADADDR__: type = import;
__EXEHDR__: type = import;
__OVERLAYADDR__: type = import;
__STACKSIZE__: type = weak, value = $0800; # 2k stack
__OVERLAYSIZE__: type = weak, value = $1000; # 4k overlay
__HIMEM__: type = weak, value = $D000;
__OVERLAYSTART__: type = export, value = __HIMEM__ - __OVERLAYSIZE__;
Added secondary linker config for C64 overlays (incl. demo program). git-svn-id: svn://svn.cc65.org/cc65/trunk@5679 b7a2c559-68d2-44c3-8de9-860c34a00d81
2012-06-03 16:16:11 +00:00
}
MEMORY {
Reduced c64-overlay.cfg's size by factoring out a different common expression.
2015-10-08 10:11:37 +00:00
ZP: file = "", define = yes, start = $0002, size = $001A;
LOADADDR: file = %O, start = %S - 2, size = $0002;
HEADER: file = %O, define = yes, start = %S, size = $000D;
Protect the C stack from overlays on the c64 target.
2020-10-15 18:00:25 +00:00
MAIN: file = %O, define = yes, start = __HEADER_LAST__, size = __OVERLAYSTART__ - __HEADER_LAST__;
Cleaned up C64 linker configs. The BSS segment and the ONCE segment share the same start address. So they need to be placed in two different memory areas. So far BSS was placed in the MAIN memory area and ONCE was placed in an additional memory area. Both memory areas were written to the output file. They just "happened" to be loadable and runnable at a stretch. Now ONCE is placed in the MAIN memory area and BSS is placed in an additional memory area. Only MAIN is written to the output file. It becomes more obvious that BSS is "just" defined to share memory with ONCE.
2016-03-13 13:32:07 +00:00
BSS: file = "", start = __ONCE_RUN__, size = __OVERLAYSTART__ - __STACKSIZE__ - __ONCE_RUN__;
Reduced c64-overlay.cfg's size by factoring out a different common expression.
2015-10-08 10:11:37 +00:00
OVL1ADDR: file = "%O.1", start = __OVERLAYSTART__ - 2, size = $0002;
OVL1: file = "%O.1", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL2ADDR: file = "%O.2", start = __OVERLAYSTART__ - 2, size = $0002;
OVL2: file = "%O.2", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL3ADDR: file = "%O.3", start = __OVERLAYSTART__ - 2, size = $0002;
OVL3: file = "%O.3", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL4ADDR: file = "%O.4", start = __OVERLAYSTART__ - 2, size = $0002;
OVL4: file = "%O.4", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL5ADDR: file = "%O.5", start = __OVERLAYSTART__ - 2, size = $0002;
OVL5: file = "%O.5", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL6ADDR: file = "%O.6", start = __OVERLAYSTART__ - 2, size = $0002;
OVL6: file = "%O.6", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL7ADDR: file = "%O.7", start = __OVERLAYSTART__ - 2, size = $0002;
OVL7: file = "%O.7", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL8ADDR: file = "%O.8", start = __OVERLAYSTART__ - 2, size = $0002;
OVL8: file = "%O.8", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL9ADDR: file = "%O.9", start = __OVERLAYSTART__ - 2, size = $0002;
OVL9: file = "%O.9", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
Added secondary linker config for C64 overlays (incl. demo program). git-svn-id: svn://svn.cc65.org/cc65/trunk@5679 b7a2c559-68d2-44c3-8de9-860c34a00d81
2012-06-03 16:16:11 +00:00
}
SEGMENTS {
Load INITBSS segment from disk. Conceptually the INITBSS segment is not initialized in any way. Therefore it makes sense to not load it from disk. However the INIT segment has to be loaded from disk and therefore moved to its run location above the INITBSS segment. The necessary move routine increases runtime RAM usage :-( Therefore we now "unnecessarily" load the INITBSS segment from disk too meaning that the INIT segment is loaded at its run location. Therefore there's no need for the move routine anymore. After all we trade disk space for (runtime) RAM space - an easy decision ;-) Notes: - The code allowing to re-run a program without re-load present so far could not have worked as far as I can see as it only avoided to re-run the move routine but still tried to re-run the code in the INIT segment that was clobbered by zeroing the BSS. Therefore I removed the code in question altogether. I'm personally not into this "dirty re-run" but if someone wants to add an actually working solution I won't block that. - INITBSS is intentionally not just merged with the DATA segment as ROM-based targets can't reuse the INIT segment for the BSS and therefore have no reason to place the INIT segment above INITBSS. - Because ROM-based targets don't copy INITBSS from the ROM (like it is done with the DATA segment) all users of INITBSS _MUST_NOT_ presume INITBSS to be initialized with zeros!
2016-02-28 18:29:37 +00:00
ZEROPAGE: load = ZP, type = zp;
LOADADDR: load = LOADADDR, type = ro;
EXEHDR: load = HEADER, type = ro;
STARTUP: load = MAIN, type = ro;
LOWCODE: load = MAIN, type = ro, optional = yes;
CODE: load = MAIN, type = ro;
RODATA: load = MAIN, type = ro;
DATA: load = MAIN, type = rw;
undo change of INIT to bss for configurations that were also using rw to reserve space, add a comment documenting the reason
2023-09-05 04:24:18 +00:00
INIT: load = MAIN, type = rw; # uninitialized, but reserves output space
Cleaned up C64 linker configs. The BSS segment and the ONCE segment share the same start address. So they need to be placed in two different memory areas. So far BSS was placed in the MAIN memory area and ONCE was placed in an additional memory area. Both memory areas were written to the output file. They just "happened" to be loadable and runnable at a stretch. Now ONCE is placed in the MAIN memory area and BSS is placed in an additional memory area. Only MAIN is written to the output file. It becomes more obvious that BSS is "just" defined to share memory with ONCE.
2016-03-13 13:32:07 +00:00
ONCE: load = MAIN, type = ro, define = yes;
BSS: load = BSS, type = bss, define = yes;
Load INITBSS segment from disk. Conceptually the INITBSS segment is not initialized in any way. Therefore it makes sense to not load it from disk. However the INIT segment has to be loaded from disk and therefore moved to its run location above the INITBSS segment. The necessary move routine increases runtime RAM usage :-( Therefore we now "unnecessarily" load the INITBSS segment from disk too meaning that the INIT segment is loaded at its run location. Therefore there's no need for the move routine anymore. After all we trade disk space for (runtime) RAM space - an easy decision ;-) Notes: - The code allowing to re-run a program without re-load present so far could not have worked as far as I can see as it only avoided to re-run the move routine but still tried to re-run the code in the INIT segment that was clobbered by zeroing the BSS. Therefore I removed the code in question altogether. I'm personally not into this "dirty re-run" but if someone wants to add an actually working solution I won't block that. - INITBSS is intentionally not just merged with the DATA segment as ROM-based targets can't reuse the INIT segment for the BSS and therefore have no reason to place the INIT segment above INITBSS. - Because ROM-based targets don't copy INITBSS from the ROM (like it is done with the DATA segment) all users of INITBSS _MUST_NOT_ presume INITBSS to be initialized with zeros!
2016-02-28 18:29:37 +00:00
OVL1ADDR: load = OVL1ADDR, type = ro;
OVERLAY1: load = OVL1, type = ro, define = yes, optional = yes;
OVL2ADDR: load = OVL2ADDR, type = ro;
OVERLAY2: load = OVL2, type = ro, define = yes, optional = yes;
OVL3ADDR: load = OVL3ADDR, type = ro;
OVERLAY3: load = OVL3, type = ro, define = yes, optional = yes;
OVL4ADDR: load = OVL4ADDR, type = ro;
OVERLAY4: load = OVL4, type = ro, define = yes, optional = yes;
OVL5ADDR: load = OVL5ADDR, type = ro;
OVERLAY5: load = OVL5, type = ro, define = yes, optional = yes;
OVL6ADDR: load = OVL6ADDR, type = ro;
OVERLAY6: load = OVL6, type = ro, define = yes, optional = yes;
OVL7ADDR: load = OVL7ADDR, type = ro;
OVERLAY7: load = OVL7, type = ro, define = yes, optional = yes;
OVL8ADDR: load = OVL8ADDR, type = ro;
OVERLAY8: load = OVL8, type = ro, define = yes, optional = yes;
OVL9ADDR: load = OVL9ADDR, type = ro;
OVERLAY9: load = OVL9, type = ro, define = yes, optional = yes;
Added secondary linker config for C64 overlays (incl. demo program). git-svn-id: svn://svn.cc65.org/cc65/trunk@5679 b7a2c559-68d2-44c3-8de9-860c34a00d81
2012-06-03 16:16:11 +00:00
}
FEATURES {
Just some beautification. git-svn-id: svn://svn.cc65.org/cc65/trunk@5984 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:55:19 +00:00
CONDES: type = constructor,
Added missing __CALLIRQ__ import attribute. git-svn-id: svn://svn.cc65.org/cc65/trunk@5983 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:22:27 +00:00
label = __CONSTRUCTOR_TABLE__,
Just some beautification. git-svn-id: svn://svn.cc65.org/cc65/trunk@5984 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:55:19 +00:00
count = __CONSTRUCTOR_COUNT__,
Renamed INITBSS to INIT and INIT to ONCE. The way we want to use the INITBSS segment - and especially the fact that it won't have the type bss on all ROM based targets - means that the name INITBSS is misleading. After all INIT is the best name from my perspective as it serves several purposes and therefore needs a rather generic name. Unfortunately this means that the current INIT segment needs to be renamed too. Looking for a short (ideally 4 letter) name I came up with ONCE as it contains all code (and data) accessed only once during initialization.
2016-03-06 20:26:22 +00:00
segment = ONCE;
Just some beautification. git-svn-id: svn://svn.cc65.org/cc65/trunk@5984 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:55:19 +00:00
CONDES: type = destructor,
Added missing __CALLIRQ__ import attribute. git-svn-id: svn://svn.cc65.org/cc65/trunk@5983 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:22:27 +00:00
label = __DESTRUCTOR_TABLE__,
Just some beautification. git-svn-id: svn://svn.cc65.org/cc65/trunk@5984 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:55:19 +00:00
count = __DESTRUCTOR_COUNT__,
segment = RODATA;
CONDES: type = interruptor,
Added missing __CALLIRQ__ import attribute. git-svn-id: svn://svn.cc65.org/cc65/trunk@5983 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:22:27 +00:00
label = __INTERRUPTOR_TABLE__,
count = __INTERRUPTOR_COUNT__,
Just some beautification. git-svn-id: svn://svn.cc65.org/cc65/trunk@5984 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:55:19 +00:00
segment = RODATA,
Added missing __CALLIRQ__ import attribute. git-svn-id: svn://svn.cc65.org/cc65/trunk@5983 b7a2c559-68d2-44c3-8de9-860c34a00d81
2013-02-12 20:22:27 +00:00
import = __CALLIRQ__;
Added secondary linker config for C64 overlays (incl. demo program). git-svn-id: svn://svn.cc65.org/cc65/trunk@5679 b7a2c559-68d2-44c3-8de9-860c34a00d81
2012-06-03 16:16:11 +00:00
}
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