Lynx cart access

[Igor]

Hi All, I'm stuck on a cart access issue with the current git version of CC65 and was wondering if anyone else was able to get cart access working.

 

I have code like this...

 

lseek(1, 0, SEEK_SET);
read(1, &buffer[0], 1024*16);

 

What seems to happen is that the first 1024 bytes are read ok, but then the remaining 15k is just junk.

When I try to put this into a loop to read 1024 bytes 16 times into my buffer, it still gives me the same result as if I was trying to read all 16k in one go.

 

I have __BLOCKSIZE__ set to 1024 in lynx.cfg

 

Any ideas what's wrong or is there a different way to read cart memory starting at a particular offset and reading a number of bytes?

[Igor]

Figured out the issue 😅

Looks like I didn't think and set the block sizes incorrectly...

 

I had __BANK0BLOCKSIZE__ set to 2048 and __BLOCKSIZE__ set to 1024, which in retrospect should have been obvious!

The git version seems to have not ported all of the code to use the correct symbols, which is a little annoying.

 

SYMBOLS {
    __STACKSIZE__:        type = export, value = 128;   # stack size in bytes
    __STARTOFDIRECTORY__: type = export, value = 203;   # start just after loader
    __BANK0BLOCKSIZE__:   type = export, value = 2048;  # Bank 0 cart block size (2048=512k ROM, 1024=256k ROM)
    __BANK1BLOCKSIZE__:   type = export, value = 0;     # Bank 1 block size
    __BLOCKSIZE__:        type = export, value = 2048;  # __BANK0BLOCKSIZE__; # backwards compatibility for older code
    __EXEHDRUSR__:        type = import;                # LNX file header, see lnxhdr.s to customise
    __BOOTLDR__:          type = import;                # Lynx boot loader
    __DEFDIR__:           type = import;                # Lynx file system directory
}