mirror of
https://github.com/KarolS/millfork.git
synced 2024-07-27 13:28:59 +00:00
27 lines
1.1 KiB
Markdown
27 lines
1.1 KiB
Markdown
|
[< back to index](../doc_index.md)
|
||
|
|
|
||
|
|
### A note about EasyFlash
|
||
|
|
|
||
|
|
The `c64_ef_small` target defines a 128 kB Easyflash cartridge image, with 72 kB effective ROM space.
|
||
|
|
The program is run directly from ROM;
|
||
|
|
typical ROM programming guidelines apply, see [the ROM vs RAM guide](./rom-vs-ram.md).
|
||
|
|
|
||
|
|
The LOROM segment ($8000-$9FFF) is fixed and is the main code segment.
|
||
|
|
|
||
|
|
The HIROM segment ($A000-$BFFF) is banked (banks numbered from `hirom0` to `hirom7`).
|
||
|
|
|
||
|
|
Initially, the `hirom0` bank is banked in.
|
||
|
|
It contains the initialization code, the initial values for RAM, and the EAPI (if used).
|
||
|
|
|
||
|
|
You can switch the bank using the `switch_hirom(0..7)` function.
|
||
|
|
|
||
|
|
In order to use EAPI, you need to include the binary distribution of EAPI at $B800 in `hirom0`, e.g.:
|
||
|
|
|
||
|
|
segment (hirom0) __eapi @ $B800 = file("eapi-am29f040-10")
|
||
|
|
|
||
|
|
and call `eapi_init()`. It sets the `errno` value.
|
||
|
|
The EAPI requires 768 bytes of RAM.
|
||
|
|
You can choose the location of EAPI by defining the `EAPI_ADDR` feature,
|
||
|
|
it should point to a page-aligned address in RAM, $200 or more.
|
||
|
|
|
||
|
|
If you want to reinitialize the EAPI without copying it from ROM again, you can call `eapi_init_again()` instead.
|