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27 lines
1.1 KiB
Markdown
27 lines
1.1 KiB
Markdown
[< back to index](../doc_index.md)
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### A note about EasyFlash
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The `c64_ef_small` target defines a 128 kB Easyflash cartridge image, with 72 kB effective ROM space.
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The program is run directly from ROM;
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typical ROM programming guidelines apply, see [the ROM vs RAM guide](./rom-vs-ram.md).
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The LOROM segment ($8000-$9FFF) is fixed and is the main code segment.
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The HIROM segment ($A000-$BFFF) is banked (banks numbered from `hirom0` to `hirom7`).
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Initially, the `hirom0` bank is banked in.
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It contains the initialization code, the initial values for RAM, and the EAPI (if used).
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You can switch the bank using the `switch_hirom(0..7)` function.
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In order to use EAPI, you need to include the binary distribution of EAPI at $B800 in `hirom0`, e.g.:
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segment (hirom0) __eapi @ $B800 = file("eapi-am29f040-10")
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and call `eapi_init()`. It sets the `errno` value.
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The EAPI requires 768 bytes of RAM.
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You can choose the location of EAPI by defining the `EAPI_ADDR` feature,
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it should point to a page-aligned address in RAM, $200 or more.
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If you want to reinitialize the EAPI without copying it from ROM again, you can call `eapi_init_again()` instead. |