Get the location in the rom where graphics are loaded

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WWakerFAN
Junior Member
Posts: 1
Joined: Thu Aug 12, 2010 9:00 am

Get the location in the rom where graphics are loaded

Post by WWakerFAN »

From what I've gathered so far, the graphics are loaded from the rom into the vram which is then accessed by the oam and so on and so forth. What I don't understand is where in the code this interaction takes place. The reason I need this is so I can uniquely identify the graphics that are being loaded without having to resort to comparing checksums.

Darthatron
Junior Member
Posts: 3
Joined: Tue Jan 11, 2011 8:13 am

Get the location in the rom where graphics are loaded

Post by Darthatron »

Each ROM can use different methods of loading graphics. But, from what I've gathered, most use DMA0 or DMA3 or CpuSet (SWI 0xB) to load uncompressed graphics into the VRAM.

 

But if they are compressed (with LZ77) they are loaded directly into the VRAM with LZ77UnCompVram (SWI 0x12), which is kind of slow, or into the WRAM with LZ77UnCompWram (SWI 0x11) and then from the WRAM to the VRAM with CpuFastSet (SWI 0xC.)

 

But then again, it's possible it uses none of these methods and the game manually loads it using a looped routine (Final Fantasy Tactics Advance does this.)

 

Anyway, you can use the "Logging" option, located in the Tools menu to check if any of the above methods are used.

 

EDIT: I suggest you read gbatek if you don't understand me.

Last edited by Darthatron on Tue Jan 25, 2011 3:46 am, edited 1 time in total.
Squall Leonhart
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Joined: Tue Mar 18, 2008 9:21 am

Get the location in the rom where graphics are loaded

Post by Squall Leonhart »

gbatek isn't completely accurate.

Squall Leonhart
Posting Freak
Posts: 1223
Joined: Tue Mar 18, 2008 9:21 am

Get the location in the rom where graphics are loaded

Post by Squall Leonhart »

gbatek isn't 100% accurate

 

read the programming manual instead

 

http://www.scribd.com/doc/6930922/Gameboy-Advance-Programming-Manual-v11

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