sd_file_list_reader's list_namelen is always 8'h00

[fjpolo]

I'm trying to parse a custom binary file to be used for a cheat module. To do that I wanted to detect the extension of the file inside SDLoader module to see if a cheat file is availabe for the selected ROM file. To do that, I thought about doing something like this:

               if (fn + file_start == sd_list_file) begin
                    if (FONT[sd_list_name[ch]][ny[2:0]][nx[2:0]])
                            if( 
                                sd_list_name[sd_list_namelen - 8] == "." &&
                                sd_list_name[sd_list_namelen - 7] == "c" &&
                                sd_list_name[sd_list_namelen - 6] == "h" && 
                                sd_list_name[sd_list_namelen - 5] == "e" &&
                                sd_list_name[sd_list_namelen - 4] == "a" &&
                                sd_list_name[sd_list_namelen - 3] == "t" &&
                                sd_list_name[sd_list_namelen - 2] == "e" &&
                                sd_list_name[sd_list_namelen - 1] == "x" && 
                                sd_list_name[sd_list_namelen] == "t"
                               ) begin
                                     color <= COLOR_TEXT_CHEAT;
                               end else begin
                                     color <= COLOR_TEXT;    // yellow
                               end

Test code was supposed to change text colour to gray if there's a *.cheatext file. I realised it wasn't changing any filename colour so I tried substracting 1, 2 and 3 to the indices, with the same result.

After that I tried something different, to check what sd_list_namelen actually was:

                if (fn + file_start == sd_list_file) begin
                    if (FONT[sd_list_name[ch]][ny[2:0]][nx[2:0]])
                        if(ch == sd_list_namelen) begin  
                            color <= COLOR_TEXT_CHEAT;
                        end else begin
                            color <= COLOR_TEXT;    // yellow
                        end

The result was that every first letter of every filename is being changed to gray colour, meaning that sd_list_namelen is always 8'h00. At least that's my interpretation given my results.

If there's a more direct and easy way to detect the end of the filename, or the extension, then I'd appreciate any support 🙂

[nand2mario]

SNESTang has a new version of sd_file_list_reader that streams the file name byte by byte. If you want you can try that. I may use that for NESTang later too.