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cc65:parameter_and_return_stacks [2010-10-30 02:53] polluks better number |
cc65:parameter_and_return_stacks [2012-03-13 08:41] (current) polluks [Accessing data on the parameter stack] Greg King |
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| + | ==== Moving the stack ==== | ||
| + | The stack isn't put in a segment; it's put into a separate memory area. | ||
| + | That area isn't named; it's implied by two expressions. The first one | ||
| + | is in the ld65 configuration file. For example, "c64.cfg" has | ||
| + | "size = $C7F3 - __STACKSIZE__". The second one is in the start-up code. | ||
| + | For example, "c64/crt0.s" has "(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)". | ||
| + | |||
| + | If it were named explicitly (it //should// be!), | ||
| + | then they would look like this: | ||
| + | |||
| + | <code> | ||
| + | HEADER: file=%O, define=yes, start=$0801, size=$000C; | ||
| + | STACK: file="", define=yes, start=$d000-__STACKSIZE__, size=__STACKSIZE__; | ||
| + | RAM: file=%O, define=yes, start=__HEADER_LAST__, size=__STACK_START__-__RAM_START__; | ||
| + | </code> | ||
| + | |||
| + | And, sp would be set to "(__STACK_START__ + __STACK_SIZE__)". | ||
| + | |||
| + | If you do want to put your stack into a segment, then you simply | ||
| + | assemble a big buffer, put a label at the end of it, and store that | ||
| + | label in sp. | ||