[< back to index](../doc_index.md) ## Adding a custom platform Every platform is defined in an `.ini` file with an appropriate name. As an extension, multiline entries are supported: if a line ends with a backslash character, the value continues to the next line. #### `[compilation]` section * `arch` – CPU architecture. It defines which instructions are available. Available values: * `nmos` (original 6502) * `strict` (NMOS without illegal instructions) * `ricoh` (Ricoh 2A03/2A07, NMOS without decimal mode) * `strictricoh` (Ricoh 2A03/2A07 without illegal instructions) * `cmos` (WDC 65C02 or 65SC02) * `65ce02` (CSG 65CE02; experimental) * `huc6280` (Hudson HuC6280; experimental) * `65816` (WDC 65816/65802; experimental; currently only programs that use only 16-bit addressing are supported) * `z80` (Zilog Z80) * `strictz80` (Z80 without illegal instructions) * `z80next` (Z80 core from ZX Spectrum Next) * `i8080` (Intel 8080) * `i8085` (Intel 8085) * `strict8085` (Intel 8085 without illegal instructions) * `gameboy` (Sharp LR35902; experimental) * `i8086` (Intel 8086; very experimental, very buggy and very, very incomplete – see the [8086 support disclaimer](../lang/x86disclaimer.md)) * `6809` (Motorola 6809; very experimental, very buggy and very, very incomplete – many language features simply do not work at all for this target) * `encoding` – default encoding for console I/O. Default: `ascii`. See [the list of available encodings](../lang/text.md). * `screen_encoding` – default encoding for screencodes (literals with encoding specified as `scr`). Default: the same as `encoding`. * `modules` – comma-separated list of modules that will be automatically imported * other compilation options (they can be overridden using commandline options): * `emit_illegals` – whether the compiler should emit illegal instructions, default `false` * `emit_cmos` – whether the compiler should emit 65C02 instructions, default is `true` on compatible processors and `false` elsewhere * `emit_65816` – which 65816 instructions should the compiler emit, either `no`, `emulation` or `native` * `decimal_mode` – whether the compiler should emit decimal instructions, default is `false` on `ricoh` and `strictricoh` and `true` elsewhere; if disabled, a software decimal mode will be used * `emit_8085` – whether the compiler should emit Intel 8085 instructions, default is `true` on compatible processors and `false` elsewhere * `emit_x80` – whether the compiler should emit instructions present on Sharp LR35902 and Z80, but absent on Intel 8080, default is `true` on compatible processors and `false` elsewhere * `emit_z80` – whether the compiler should emit Zilog Z80 instructions not covered by `emit_x80`, default is `true` on compatible processors and `false` elsewhere * `prevent_jmp_indirect_bug` – whether the compiler should try to avoid the indirect JMP bug, default is `false` on 65C02-compatible or non-6502 processors and `true` elsewhere * `compact_dispatch_params` – whether parameter values in return dispatch statements may overlap other objects, default is `true`. This may cause problems if the parameter table is stored next to a hardware register that has side effects when reading. * `lunix` – generate relocatable code for LUnix/LNG, default is `false` * `zeropage_register` – reserve a certain amount of bytes of zero page as a pseudoregister to increase language features. Default: `4` if targeting a 6502-based architecture, `0` otherwise. `true` is a synonym of the current compiler default (currently: 4) and `false` is a synonym for 0. * `inline` - inline functions automatically by default, default is `false`. * `ipo` - enable interprocedural optimization, default is `false`. * `function_fallthrough` – whether should replace a tail call by simply putting one function after another, default is `true`. * `function_deduplication` – whether identical functions should be merged into one function, default is `true`. * `subroutine_extraction` – whether identical fragments of functions should be extracted into subroutines, default is `false`. * `lenient_encoding` - allow for automatic substitution of invalid characters in string literals using the default encodings, default is `false`. * `use_shadow_registers_for_irq` – use Z80 shadow registers in interrupt routines, default is `true` for Z80 and `false` otherwise * `ix_stack` – use the IX register to access stack variables, default is `true` for Z80 and 8086, `false` otherwise * `iy_stack` – use the IY register to access stack variables, default is `false` * `ix_scratch` – allow using the IY register for other purposes, default is `false` * `iy_scratch` – allow using the IY register for other purposes, default is `false` * `software_stack` – use software stack for stack variables, default is `false`. Applicable only to 6502-based targets. * `output_intel_syntax` – use Intel syntax instead of Zilog syntax, default is `true` for Intel 8080/8085 and `false` otherwise #### `[define]` section This section defines values of features of the target. See the [preprocessor documentation](../lang/preprocessor.md) for more info. #### `[allocation]` section * `zp_pointers` – either a list of comma separated zeropage addresses that can be used by the program as zeropage pointers, or `all` for all. Each value should be the address of the first of two free bytes in the zeropage. Only used for 6502-based targets. Cannot be used together with `zp_bytes`. * `zp_bytes` – either a list of comma separated zeropage byte addresses or address ranges that can be used by the program in zeropage, or `all` for all. Only used for 6502-based targets. Cannot be used together with `zp_pointers`. * `segments` – a comma-separated list of segment names. A segment named `default` is always required. Default: `default`. In all options below, `NAME` refers to a segment name. * `default_code_segment` – the default segment for code and const arrays. Note that the default segment for writable arrays and variables is always `default`. Default: `default` * `ram_init_segment` – the segment storing a copy of initial values for preinitialized writable arrays and variables. The segment cannot be `default`. See [the ROM vs RAM guide](./rom-vs-ram.md) for more information. Default: none. * `segment_NAME_start` – the first address used for automatic allocation in the segment. Note that on 6502-like targets, the `default` segment shouldn't start before $200, as the $0-$1FF range is reserved for the zeropage and the stack. The first object defined in `segment_NAME_layout` (usually the `main` function) will be placed as close to the beginning of its segment as possible, but not necessarily at `segment_NAME_start` * `segment_NAME_end` – the last address in the segment * `segment_NAME_codeend` – the last address in the segment for code and const arrays. Only uninitialized variables are allowed between `segment_NAME_codeend` and `segment_NAME_end`. Default: the same as `segment_NAME_end`. * `segment_NAME_datastart` – the first address used for non-zeropage variables, or `after_code` if the variables should be allocated after the code. Default: `after_code`. * `segment_NAME_bank` – the bank number the segment belongs to. Default: `0`. For better debugging on NES, RAM segments should use bank number `$ff`. * `segment_NAME_fill` – the byte value used to fill gaps and other unused space in the bank. Default: `0`. * `segment_NAME_layout` – a comma-separated list of object names that defines in what order the objects are laid out in the segment. One item has to be `*`, it means "all the other objects". For example, `a,b,*,c,d` means that the output will contain `a` first, then `b`, then everything else except for `c` and `d`, then `c` and finally `d`. If an object from that list does not exist, it is ignored. Default: `main,*` #### `[output]` section * `style` – how multi-segment programs should be output: * `single` – output a single file, based mostly, but not necessarily only on data in the `default` segment (the default) * `lunix` – like `single`, but add data necessary for relocation between code and data (requires `lunix` option in the `compilation` section) * `per_segment` – generate a separate file with each segment * `format` – output file format; a comma-separated list of tokens: * literal byte values * `startaddr` – little-endian 16-bit address of the first used byte of the compiled output (not necessarily the segment start) * `startaddr_be` – the same, but big-endian * `endaddr` – little-endian 16-bit address of the last used byte of the compiled output (usually not the segment end) * `endaddr_be` – the same, but big-endian * `startaddr+123`, `startaddr_be+123`, `endaddr+123`, `endaddr_be+123` – the same, but incremented by the given number * `startaddr-123`, `startaddr_be-123`, `endaddr-123`, `endaddr_be-123` – the same, but decremented by the given number * `startpage` – the high byte of `startaddr` * `length` – little-endian 16-bit length of the compiled output; `endaddr - startaddr + 1` * `length_be` – the same, but big-endian * `length+123`, `length_be+123` – the same, but incremented by the given number * `length-123`, `length_be-123` – the same, but decremented by the given number * `allocated` – all used bytes * `pagecount` – the number of pages used by all used bytes (including partially filled pages) * `:` - inclusive range of bytes * `::` - inclusive range of bytes in a given segment * `d88` - a D88 floppy disk image for PC-88 * `tap` - a tape disk image for ZX Spectrum * `extension` – target file extension, with or without the dot * `bbc_inf` – should the `.inf` file with file metadata for BBC Micro be created * `gb_checksum` – should the main output file be patched with Game Boy-compatible checksums * `labels` – format of the label file: * `vice` (the default) – format compatible with the Vice emulator. The extension is `.lbl`. * `nesasm` – format used by the NESASM assembler. The extension is `.fns`. * `sym` – format used by the WLA/DX assembler. The extension is `.sym`. * `fceux` – multi-file format used by the FCEUX emulator. The extension is `.nl`.