ROM padding question

[matteus]

My Sonic Mania FMV ROM is 4,096KB. I removed 10 216x120 images of black from the ROM and the size was still 4,096KB is there any way of knowing what the true size is and how much space I have left? I'd like to try and squeeze a VGM file in if I can

[Stef]

Using an hexa editor to see how much 0 filled space you have at the end ? :p

[matteus]

Stef... really now lol I'm crap at that stuff lol okay what hex editor should I use?

[Stef]

Whatever free hexa editor should do the job, myself i'm using FrHed

[matteus]

From Address 003ee4e0 to 00effff0 its nothing but "00"

[Staffan]

Just google "html5 hex editor", and you get a browser version. I used it to reverse engineer the old ansi bbs image protocol. . You can just drag the file you want to open to your browser.

[Sik]

From Address 003ee4e0 to 00effff0 its nothing but "00"

The end of the ROM should be 003FFFFF =P

[HardWareMan]

From Address 003ee4e0 to 00effff0 its nothing but "00"

The end of the ROM should be 003FFFFF =P

The ROM windows should be $000000-$3FFFFF, but ROM itself not required to be up to $3FFFFF.

[Sik]

It's a padded ROM. And the issue was going up to $EFFFFF which is definitely way beyond ROM area. Something went wrong there.

I'm assuming the actual padding is from $3EE4E0 to $3FFFFF.

[matteus]

Sorry TYPO! last address in the ROM file is 003ffff0. I know zero about hex and ROM addresses so feel free to give me a bit of an education in them!

So addresses $3EE80 to $3FFFF0

[matteus]

Okay I was using the HEX editor in Notepad++ which clearly isn't that great! Now download Frhed

[Manveru]

In the makefile the rom is aligned according to a value.
SGDK size is 128kb: out/rom.bin -sizealign 131072
You can remove that alignment or reduce it to see where you are.

[Stef]

ROM padding is here for some reason though, unpadded ROM won't work on some flash cart.

[Manveru]

yeah i know, but is a good way to know the real size of a game rom.

[cero]

size -t *.o

The totals dec field will be very close to the used ROM size.