rgblink —
linkerscript file format
The linkerscript is an external file that allows the user to specify the order
of sections without the need for doing so before assembling each object file.
The placement of sections specified in the linkerscript is done before the
sections whose placement is defined in the source code.
A linkerscript consists on a series of banks followed by a list of sections and,
optionally, commands. They can be lowercase or uppercase, it is ignored. Any
line can contain a comment starting with
‘
;’ that ends at the end of the line:
ROMX $F ; This is a comment
"Functions to read array"
ALIGN 8
"Array aligned to 256 bytes"
WRAMX 2
"Some variables"
Numbers can be in decimal or hexadecimal format (the prefix is
‘
$’). It is an error if any section name
or command are found before setting a bank.
Files can be included by using the
INCLUDE
keyword followed by a string with the path of the file that has to be
included.
The possible bank types are:
ROM0,
ROMX,
VRAM,
WRAM0,
WRAMX,
OAM and
HRAM. Types
ROMX,
VRAM,
WRAMX and
SRAM are
banked, which means that it is needed to specify a bank after the type.
When a new bank statement is found, sections found after it will be placed right
from the beginning of that bank. If the linkerscript switches to a different
bank and then it comes back to the previous one it will continue from the last
address that was used.
The only two commands are
ORG and
ALIGN:
- ORG sets the address in
which new sections will be placed. It can not be lower than the current
address.
- ALIGN will increase the
address until it is aligned to the specified boundary (it tries to set to
0 the number of bits specified after the command:
ALIGN 8 will align to $100).
Note: The bank, alignment, address and type of sections can be specified both in
the source code and in the linkerscript. For a section to be able to be placed
with the linkerscript the bank must be left unassigned in the source code or
be the same as the one specified in the linkerscript. The address and
alignment musn't be set.
rgbasm(1),
rgblink(1),
rgbfix(1),
rgbds(5),
rgbds(7)
rgblink was originally written by Carsten
Sørensen as part of the ASMotor package, and was later packaged in
RGBDS by Justin Lloyd. It is now maintained by a number of contributors at
https://github.com/rednex/rgbds.