Sega Genesis Dev Kit (SGDK)

[djcouchycouch]

Hi Stef!

When running on Everdrive, the firmware already initializes RAM. That means that any unintentionally uninitialised variables in rom might be initialized by accident and subtle bugs not found until run as a real cart.

Would it be possible to have the SGDK set all the memory to a known debug value at start up before any code is run? Like a series of 0xdedbeef0xdeadbeef. That way it would be much easier to find variables with bad values.

Thanks!
DJCC

[djcouchycouch]

Also!

How do I build with SGDK so that I can get the watch variable window working in Gens? I lost the instructions to do this.

[Stef]

You can easily modify SGDK so it resets memory with a specific pattern, just replace line 83 of sega.s file :

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        moveq   #0,%d0

by

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        move.l  #0xDEADBEEF,%d0

sega.s is recompiled every time in your own project so you don't even need to recompile the whole library
Also i prefer to avoid doing that modification in the official version as it can lead to undesirable effect for people expecting SGDK to reset memory to 0.

For the watch variables, you have the 'debug' and 'debugall' target in the makefile but honestly support is not good enough yet in GensKMod++
You have also some watch support in GensKMod but i thing it's all manual (don't need any specific debug option in GCC).

[djcouchycouch]

Thanks!

For the watch variables, you have the 'debug' and 'debugall' target in the makefile but honestly support is not good enough yet in GensKMod++
You have also some watch support in GensKMod but i thing it's all manual (don't need any specific debug option in GCC).

I remember seeing a thing where GensKMod would show the correct variable names in the watch window. You had to compile your project in a certain way to get a file out with the names and locations. And GensKMod would load it.

[Stef]

Using the "debug" target you will obtain a rom.wch file, i guess KMod use it for variable watch but i think you specify which variable you want to watch directly for GensKMod then you can save watchs so it restore them automatically on next session. Honestly i never used this feature in KMod so i'm not sure about how use it but i guess Kaneda could help you there

[djcouchycouch]

Using the "debug" target you will obtain a rom.wch file

Yes, it's a noob question: How do you compile the debug target?

[Stef]

SGDK use makefile to build project.
Are you using command line compilation or Code::blocks IDE ?
For command line compilation just use :

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make -f makefile.gen debug

So it will choose the "debug" target instead of the default one.
In Code::Blocks you can define severals project build target, just create a debug one and modify the makefile "Build project/target" command by appending "debug" to the command line :



In the CB tutorial i just created a "default" project configuration which the default makefile setting (optimized) but usually we have "release" and "debug" configurations.

[KanedaFr]

Using the "debug" target you will obtain a rom.wch file, i guess KMod use it for variable watch but i think you specify which variable you want to watch directly for GensKMod then you can save watchs so it restore them automatically on next session. Honestly i never used this feature in KMod so i'm not sure about how use it but i guess Kaneda could help you there

err... nobody read the help file, no ?

So...on GensKMod > Option > Debug, be sure to check "Auto load watchers & structures"
if you open a rom, it will search for <romname>.wch and will load it
Then, you'll be able to play with Cpu>Debug>Watcher

note that you could also include kdebug.h and get some trace output in Cpu>Debug > Messages

I found some times ago a better version of watchers and messages windows that my own (GensSomethingElse) if you're interested

EDIT : it's called Gens11svn304, google for it
Menu Tools > RAM Watch

[Stef]

I tried to load the wch file generated from NM file which has been converted by NM2WCH but i guess this is something totally different as it end up with some invalid variables in GensKMod :p

[Stef]

Version 0.94 released
Checkout the first page !

[Chilly Willy]

Version 0.94 released

New bitmap support works great! Works fine on real hardware and is faster than ever, even if just 1 FPS.

[Stef]

Thanks
1 FPS ? Ah yeah it's what you gain from the previous version... not that much but still better than nothing

[Chilly Willy]

Thanks
1 FPS ? Ah yeah it's what you gain from the previous version... not that much but still better than nothing

It's not as much on the top end, 10 goes to 11 FPS, but it's much more on the low end where 5 goes to 6.

[peekpoke]

There was some not important question about genres sprites support Just figured everything by myself - and was impressed by great possibilities that SGDK offers! Thank you very much for your work!

[POLYGAMe]

Is it possible to use SGDK with XCode? My main dev system is my Mac...