This section contains information that may be useful to know or important when upgrading to a newer GBDK release.
GBDK 2020 versions
Porting to GBDK 2020 4.0.2
- The default font has been reduced from 256 to 96 characters. Code using special characters may need to be updated.
Porting to GBDK 2020 4.0.1
- Important! : The
WRAM
memory region is no longer automatically initialized to zeros during startup.
- Any variables which are declared without being initialized may have indeterminate values instead of 0 on startup. This might reveal previously hidden bugs in your code.
- Check your code for variables that are not initialized before use.
- In BGB you can turn on triggering exceptions (options panel) reading from unitialized RAM. This allows for some additional runtime detection of uninitialized vars.
- In .ihx files, multiple writes to the same ROM address are now warned about using ihxcheck.
set_*_tiles()
now wrap maps around horizontal and vertical boundaries correctly. Code relying on it not wrapping correctly may be affected.
Porting to GBDK 2020 4.0
- GBDK now requires SDCC 4.0.3 or higher
- The old linker
link-gbz80
has been REMOVED, the linker sdldgb from SDCC is used.
- Due to the linker change, there are no longer warnings about multiple writes to the same ROM address.
- GBDK now generates .ihx files, those are converted to a ROM using makebin (lcc can do this automatically in some use cases)
- Setting ROM bytes directly with
-Wl-yp0x<address>=0x<value>
is no longer supported. Instead use makebin flags. For example, use -Wm-yC
instead of -Wl-yp0x143=0xC0
.
- OAM symbol has been renamed to _shadow_OAM, that allows accessing shadow OAM directly from C code
Porting to GBDK 2020 3.2
- No significant changes required
Porting to GBDK 2020 3.1.1
- No significant changes required
Porting to GBDK 2020 3.1
- No significant changes required
Porting to GBDK 2020 3.0.1
- LCC was upgraded to use SDCC v4.0. Makefile changes may be required
- The symbol format changed. To get usable symbols turn on
.noi
output (LCC argument: -Wl-j
)can be enabled and you can use noi2sym
- ?? Suggested: With LCC argument:
-Wa-l
(sdasgb:-a All user symbols made global
)
- In SDCC 3.6.0, the default for char changed from signed to unsigned.
- If you want the old behavior use
--fsigned-char
.
- lcc includes
--fsigned-char
by default
- Explicit declaration of unsigned vars is encouraged (for example, '15U' instead of '15')
.init
address has been removed
Historical GBDK versions
GBDK 1.1 to GBDK 2.0
- Change your int variables to long if they have to be bigger than 255. If they should only contain values between 0 and 255, use an unsigned int.
- If your application uses the delay function, you'll have to adapt your delay values.
- Several functions have new names. In particular some of them have been changed to macros (e.g. show_bkg() is now SHOW_BKG).
- You will probably have to change the name of the header files that you include.