Settings

The top-level settings attribute specifies many options to customize the generated linker script. Note that many of these options can be customized per segment too.

All the settings are optional. Unspecified options will use the default value for it. Note that using certain settings may require specifying other options as well.

Settings

`base_path`

All the emitted paths are relative to this path. Useful when all the files are relative to the same directory, like a build folder.

Example

settings:
  base_path: build/us

Valid values

Any valid path.

Default value

Defaults to empty path.

`linker_symbols_style`

The styling used for the automatically generated linker symbols.

These symbols correspond to the vram and rom address of the segments and the vram address of the sections of the corresponding segment.

To be precise, symbols are generated for the following:

Segment's rom start, end and size.
Segment's vram start, end and size.
Segment's allocatable vram start, end and size.
Segment's noload vram start, end and size.
Section's vram start, end and size.
File's linker offset.
Vram's class's start, end and size.

Example

settings:
  linker_symbols_style: makerom

Valid values

splat: Produces SCREAMING_CASE symbols. Given a segment named boot:
- Segment rom: boot_ROM_START, boot_ROM_END and boot_ROM_SIZE.
- Segment vram: boot_VRAM, boot_VRAM_END and boot_VRAM_SIZE.
- Segment allocatable: boot_alloc_VRAM, boot_alloc_VRAM_END and boot_alloc_VRAM_SIZE.
- Segment noload: boot_noload_VRAM, boot_noload_VRAM_END and boot_noload_VRAM_SIZE.
- Section vram (not limited to the foloowing examples):
  - .text: boot_TEXT_START, boot_TEXT_END and boot_TEXT_SIZE.
  - .data: boot_DATA_START, boot_DATA_END and boot_DATA_SIZE.
  - .bss: boot_BSS_START, boot_BSS_END and boot_BSS_SIZE.
- File linker_offset_name: {name}_OFFSET.
- Vram class: {name}_VRAM_CLASS_START, {name}_VRAM_CLASS_END and {name}_VRAM_CLASS_SIZE.
makerom: Produces _camelCase symbols. Given a segment named boot:
- Segment rom: _bootSegmentRomStart, _bootSegmentRomEnd and _bootSegmentRomSize.
- Segment vram: _bootSegmentStart, _bootSegmentEnd and _bootSegmentSize.
- Section vram (not limited to the foloowing examples):
  - .text: _bootSegmentTextStart, _bootSegmentTextEnd and _bootSegmentTextSize.
  - .data: _bootSegmentDataStart, _bootSegmentDataEnd and _bootSegmentDataSize.
  - .bss: _bootSegmentBssStart, _bootSegmentBssEnd and _bootSegmentBssSize.
- File linker_offset_name: _{name}Offset.
- Vram class: _{name}VramClassStart, _{name}VramClassEnd and _{name}VramClassSize.

Default value

splat

`hardcoded_gp_value`

Emits a _gp symbol with the specified value, essentially hardcoding the value.

_gp is requiered for initializing the $gp register.

This can be useful for decomp projects on the discovering step, but it would be problematic on shiftable builds.

It is strongly recommended to use the gp_info field of the corresponding segment instead of hardcoding the _gp value, since this will this value to shift properly when modifying the code of the builds.

Providing both gp_info and a hardcoded_gp_value is not a valid combination and slinky will refuse to process the file.

Example

settings:
  hardcoded_gp_value: 0x800E4090

Valid values

A positive integer or null.

Default value

null

`d_path`

Output path for the .d (dependencies) file.

A dependencies file consists on a file that lists required files to build a given file. This kind of dependency files can be consumed by build systems like make or ninja.

The generated .d file will list all the paths listed by every segment as required to build a given target_path.

This file will also contain an -include directive for every path listed, but replacing their extensions with .d.

This file is generated only if d_path is specified.

This option requires target_path.

Example

settings:
  d_path: linker_scripts/game.d
  target_path: build/game.elf

Valid values

Non-empty path.

`target_path`

The path to the file that will result of linking, usually an .elf file.

Currently only used by the d_path setting.

Example

settings:
  d_path: linker_scripts/game.d
  target_path: build/game.elf

Valid values

Non-empty path.

`symbols_header_path`

Path to output a C header containing the generated linker symbols.

The symbols are declared as extern and their type can be customized with symbols_header_type and symbols_header_as_array.

This file is generated only if symbols_header_path is specified.

Example

settings:
  symbols_header_path: include/linker_symbols.h

Valid values

Non-empty path.

`symbols_header_type`

The type used for every linker symbol on the generated header.

This option is ignored if symbols_header_path was not set.

Example

settings:
  symbols_header_path: include/linker_symbols.h
  symbols_header_type: u32

Generates entries like:

extern u32 main_BSS_START[];

Valid values

String

Default value

char

`symbols_header_as_array`

Allows customizing if the entries from the generated symbols header should be declared as arrays or not.

This option is ignored if symbols_header_path was not set.

Example

settings:
  symbols_header_path: include/linker_symbols.h
  symbols_header_type: Addr
  symbols_header_as_array: False

Generates entries like:

extern Addr main_BSS_START;

Valid values

Boolean

Default value

True

`paths_list_path`

Path to output a plain text file listing every path listed in the input file.

This is useful for generating a list of files to pass to a linker with the @path/to/file.list syntax.

Example

settings:
  paths_list_path: build/game.us.o_files.list

Valid values

Non-empty path.

`sections_allowlist`

A list of sections to that should be preserved during linking.

Usually used to avoid discarding debugging sections.

Example

settings:
  sections_allowlist: [.mdebug, .note, .comment]

Valid values

List of strings.

Default value

[]

`sections_allowlist_extra`

A list of sections to that should be preserved during linking.

This setting works the same as same as sections_allowlist. This option exists as a way to have a default list of sections to be preserved that won't be overrided if the user wants to specify their own allow list by setting sections_allowlist.

These defaults exists because some linkers (like clang's lld) complain if some sections like .shstrtab are not listed explicitly and a wildcard was used on the /DISCARD/ section (see discard_wildcard_section), seemingly producing lld to discard those sections. So to avoid issues when wanting to use other linkers we emit the section by default.

Example

settings:
  sections_allowlist_extra:
    - .shstrtab
    - .strtab
    - .symtab

Valid values

List of strings.

Default value

[.symtab, .strtab, .shstrtab]

`sections_denylist`

List of sections to be discarded.

This option work independently from discard_wildcard_section.

Example

settings:
  sections_denylist: [.reginfo, .got]

Valid values

List of strings.

Default value

[.reginfo, .MIPS.abiflags, .MIPS.options, .note.gnu.build-id, .interp, .eh_frame]

`discard_wildcard_section`

Toggles emitting a discard section with a wildcard (*) entry, essentially discarding every section and file that is not explicitly listed on the linker script.

This option work independently from sections_denylist.

GNU LD docs for /DISCARD/: https://sourceware.org/binutils/docs/ld/Output-Section-Discarding.html#index-_002fDISCARD_002f

Example

settings:
  discard_wildcard_section: False

Valid values

Boolean.

Default value

True

`single_segment_mode`

Change linker script generation to be more similar to an standard linker script, removing the multi-segment handling logic that is used mainly for N64 projects.

With this mode active the emitted sections will correspond directly to alloc_sections and noload_sectionss.

This requires the YAML document to have exactly 1 segment under the [segments.md#segments](segments.md#segments) section.

The segments.md#fixed_vram property is used to specify the vram for the first section, then the following sections' vram grow accordingly.

Example

settings:
  single_segment_mode: True

Valid values

Boolean.

Default value

False

`partial`

Configuration for partial linking support.

For more information about this field see the dedicated partial.md document.

Example

settings:
  partial:
    build_segments_folder: segments/
    scripts_folder: linker_scripts/partial/

Valid values

See partial.md to see the structure.

Default value

null

`alloc_sections`

List of allocatable sections (the ones that take ROM space).

The sections from this list will be emitted for each file in the specified order.

A null value can be used to signal that no allocatable sections should be emitted. Setting to null will avoid emitting linker symbols for allocatable sections too.

This option can be overriden per segment, see segments.md#alloc_sections for more info.

Example

settings:
  alloc_sections: [.rodata, .text, .data]

Valid values

List of strings or null.

Default value

[.text, .data, .rodata, .sdata]

`noload_sections`

List of noload sections (the ones that don't take ROM space).

The sections from this list will be emitted for each file in the specified order.

A null value can be used to signal that no noload sections should be emitted. Setting to null will avoid emitting linker symbols for noload sections too.

This option can be overriden per segment, see segments.md#noload_sections for more info.

Example

settings:
  noload_sections: [.bss]

Valid values

List of strings or null.

Default value

[.sbss, .scommon, .bss, COMMON]

`subalign`

The value to use in the SUBALIGN directives.

If the value is null then disables using SUBALIGN directives.

GNU LD docs for SUBALIGN: https://sourceware.org/binutils/docs/ld/Forced-Input-Alignment.html#index-SUBALIGN_0028subsection_005falign_0029

This option can be overriden per segment, see segments.md#subalign for more info.

Example

settings:
  subalign: 4

Valid values

Positive integers or null.

Default value

null

`segment_start_align`

Force aligning the beginning of the segment to the specified value.

If the value is null then no alignment will be forced.

This option can be overriden per segment, see segments.md#segment_start_align for more info.

Example

settings:
  segment_start_align: 0x10

Valid values

Positive integers or null.

Default value

null

`segment_end_align`

Force aligning the end of the segment to the specified value.

If the value is null then no alignment will be forced.

This option can be overriden per segment, see segments.md#segment_end_align for more info.

Example

settings:
  segment_end_align: 0x10

Valid values

Positive integers or null.

Default value

null

`section_start_align`

Force aligning the start of each section to the specified value.

If the value is null then no alignment will be forced on the start of the sections.

Note that this field and sections_start_alignment does not override each other, meaning that if this field is non-null and a section is specified in sections_start_alignment then both alignments will be applied to given section.

This option can be overriden per segment, see segments.md#section_start_align for more info.

Example

settings:
  section_start_align: 0x10

Valid values

Positive integers or null.

Default value

null

`section_end_align`

Force aligning the end of each section to the specified value.

If the value is null then no alignment will be forced on the end of the sections.

Note that this field and sections_end_alignment does not override each other, meaning that if this field is non-null and a section is specified in sections_end_alignment then both alignments will be applied to given section.

This option can be overriden per segment, see segments.md#section_end_align for more info.

Example

settings:
  section_end_align: 0x10

Valid values

Positive integers or null.

Default value

null

`sections_start_alignment`

Allows to specify different alignments for the start of every section.

If a specific section is not pressent on this mapping then no alignment will be forced on the given section.

Note that this field and section_start_align does not override each other, meaning that if a section is specified in this field and section_start_align is non-null then both alignments will be applied to the section.

This option can be overriden per segment, see segments.md#sections_start_alignment for more info.

Example

settings:
  sections_start_alignment: { .text: 128, .rodata: 0x40, .sdata: 0x8 }

Valid values

A mapping of strings as keys and positive numbers as values.

Default value

Empty mapping.

`sections_end_alignment`

Allows to specify different alignments for the end of every section.

If a specific section is not pressent on this mapping then no alignment will be forced on the given section.

Note that this field and section_end_align does not override each other, meaning that if a section is specified in this field and section_end_align is non-null then both alignments will be applied to the section.

This option can be overriden per segment, see segments.md#sections_end_alignment for more info.

Example

settings:
  sections_end_alignment: { .text: 128, .rodata: 0x40, .sdata: 0x8 }

Valid values

A mapping of strings as keys and positive numbers as values.

Default value

Empty mapping.

`wildcard_sections`

Toggles using wildcards (*) as suffix in the emitted sections.

For example the .rodata section would be emitted as .rodata* if this option is enabled.

This option can be overriden per segment, see segments.md#wildcard_sections for more info.

Example

settings:
  wildcard_sections: False

Valid values

Boolean

Default value

True

`fill_value`

Allows to specify the value of the FILL statement emitted for every segment of the linker script.

If the value is null then no FILL statements will be emitted.

GNU LD docs for FILL: https://sourceware.org/binutils/docs/ld/Output-Section-Data.html#index-FILL_0028expression_0029

This option can be overriden per segment, see segments.md#fill_value for more info.

Example

settings:
  fill_value: 0xA1F

Which emits the following FILL statement:

FILL(0x00000A1F);

Valid values

Positive integers or null.

Default value

0

`sections_subgroups`

Allows to specify one or multiple sections that should be emitted alongside another section for each file, instead of getting their own "proper" section.

This setting can be overriden per segment. See the sections_subgroups on the segments document.

Example

settings:
  sections_subgroups: { .rodata: [.rdata], .text: [.ctor, .dtor] }

segments:
  - name: boot
    files:
      - { path: boot_main.o }
      - { path: utils.o }

The above example produces output like the following (stripped a bit for demostrative reasons):

        /* -- SNIP -- */

        boot_TEXT_START = .;
        boot_main.o(.text*);
        boot_main.o(.ctor*);
        boot_main.o(.dtor*);
        utils.o(.text*);
        utils.o(.ctor*);
        utils.o(.dtor*);
        boot_TEXT_END = .;
        boot_TEXT_SIZE = ABSOLUTE(boot_TEXT_END - boot_TEXT_START);

        /* -- SNIP -- */

        boot_RODATA_START = .;
        boot_main.o(.rodata*);
        boot_main.o(.rdata*);
        utils.o(.rodata*);
        utils.o(.rdata*);
        boot_RODATA_END = .;
        boot_RODATA_SIZE = ABSOLUTE(boot_RODATA_END - boot_RODATA_START);

        /* -- SNIP -- */

Note how .ctor and .dtor sections are emitted alongside the .text sections and they are emitted within the TEXT group. Same for .rdata being emitted alongside .rodata sections.

Valid values

A mapping of sections (strings) as keys and a list of sections (strings) as values.

Default value

Empty mapping.

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Settings

Table of Contents

base_path

Example

Valid values

Default value

linker_symbols_style

Example

Valid values

Default value

hardcoded_gp_value

Example

Valid values

Default value

d_path

Example

Valid values

target_path

Example

Valid values

symbols_header_path

Example

Valid values

symbols_header_type

Example

Valid values

Default value

symbols_header_as_array

Example

Valid values

Default value

paths_list_path

Example

Valid values

sections_allowlist

Example

Valid values

Default value

sections_allowlist_extra

Example

Valid values

Default value

sections_denylist

Example

Valid values

Default value

discard_wildcard_section

Example

Valid values

Default value

single_segment_mode

Example

Valid values

Default value

partial

Example

Valid values

Default value

alloc_sections

Example

Valid values

Default value

noload_sections

Example

Valid values

Default value

subalign

Example

Valid values

Default value

segment_start_align

Example

Valid values

`base_path`

`linker_symbols_style`

`hardcoded_gp_value`

`d_path`

`target_path`

`symbols_header_path`

`symbols_header_type`

`symbols_header_as_array`

`paths_list_path`

`sections_allowlist`

`sections_allowlist_extra`

`sections_denylist`

`discard_wildcard_section`

`single_segment_mode`

`partial`

`alloc_sections`

`noload_sections`

`subalign`

`segment_start_align`

`segment_end_align`

`section_start_align`

`section_end_align`

`sections_start_alignment`

`sections_end_alignment`

`wildcard_sections`

`fill_value`

`sections_subgroups`