// Provided under the GPL v2 license. See the included LICENSE.txt for details.

// 7800rmt2asm - Reads in either a SAP wrapped RMT file, or an RMT file, and

// creates relocatable assembly code from it.

// The program does what it says, but could use some source clean-up and

// options.

// Format info: https://github.com/VinsCool/RASTER-Music-Tracker/blob/main/asm_src/Patch-16/rmtformat.txt

#define HEADER_VERSION_INFO "7800rmt2asm 0.1"

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <stdint.h>

#pragma pack(push, 1)

struct rmtheader {

};

struct upoint {

uint16_t pointer;

};

#pragma pack(pop)

int main (int argc, char **argv)

{

long t,rmtstart,size;

FILE *in,*out;

char outname[1024];

unsigned char *buffer;

struct rmtheader *rmthead;

struct upoint *myupoint;

uint8_t *lo,*hi;

uint16_t val;

fprintf(stderr, "%s %s %s\n", HEADER_VERSION_INFO, __DATE__, __TIME__);

if(argc==1)

{

fprintf(stderr,"Usage:\n%s [RMT or SAP filename]\n",argv[0]);

return(1);

}

strncpy(outname,argv[1],1024);

int len=strlen(outname);

// strip the first extension found in the original filename

for(t=len;t>0;t--)

{

if(outname[t]=='.')

{

outname[t]=0;

break;

}

if((outname[t]=='/')||(outname[t]=='/'))

break;

}

strcat(outname,".rmta");

in=fopen(argv[1],"rb");

if(in==NULL)

{

fprintf(stderr,"ERR: couldn't open file '%s' for reading.\n",argv[1]);

return(2);

}

fseek(in,0,SEEK_END);

size=ftell(in);

fseek(in,0,SEEK_SET);

if(size<16)

{

fprintf(stderr,"ERR: file size of '%s' is %ld bytes.\n",argv[1],size);

return(3);

}

buffer=malloc(size 6);

if(fread(buffer 6,1,size,in) == 0)

{

fprintf(stderr,"ERR: couldn't read from '%s'.\n",argv[1]);

return(4);

}

fclose(in);

// Search for our RMT4 header...

for(t=0;t<size-10;t )

{

if ( (buffer[t]=='R') && (buffer[t 1]=='M') && (buffer[t 2]=='T') && (buffer[t 3]=='4'))

break;

}

if(t==size-10)

{

fprintf(stderr,"ERR: no RMT4 header was found in '%s'.\n",argv[1]);

return(5);

}

// Try to create our output file...

out=fopen(outname,"wb");

if(out==NULL)

{

fprintf(stderr,"ERR: couldn't open '%s' for writing.\n",outname);

return(4);

}

rmtstart=t;

rmthead=(void *)buffer rmtstart-6;

uint16_t memstart;

uint16_t startrange,endrange;

// If the RMT4 file doesn't have the load vector, than calculate the RMT load location.

// This isn't normally a problem, but rmt files prepped for 7800 may have the vectors

// stripped, since it doesn't use them.

if((unsigned char *)rmthead<buffer)

memstart = rmthead->pointer_to_instrument_pointers - 0x10;

else

memstart = rmthead->vect2_start;

int i;

// The header...

fprintf(out,";RMTA - This line is required for 7800basic autodetection. Don't remove.\n");

fprintf(out,";#### %s - converted by %s %s %s\n\n", outname, HEADER_VERSION_INFO, __DATE__, __TIME__);

fprintf(out,".RMTSTART SET .\n");

fprintf(out,"\n");

fprintf(out,"\n");

fprintf(out," ; #### RMT header...\n");

fprintf(out," .byte \"RMT4\" ; magic\n");

fprintf(out," .byte $x ; tracklen\n",rmthead->track_len);

fprintf(out," .byte $x ; song speed\n",rmthead->song_speed);

fprintf(out," .byte $x ; player freq\n",rmthead->player_freq);

fprintf(out," .byte $x ; format version number\n",rmthead->format_version_number);

fprintf(out," .word (.RMTSTART $x) ; pointer to instrument pointers\n",(rmthead->pointer_to_instrument_pointers)-memstart);

fprintf(out," .word (.RMTSTART $x) ; pointer to track pointers, lo\n",(rmthead->pointer_to_track_pointers_lo)-memstart);

fprintf(out," .word (.RMTSTART $x) ; pointer to track pointers, hi\n",(rmthead->pointer_to_track_pointers_hi)-memstart);

fprintf(out," .word (.RMTSTART $x) ; pointer to song\n",(rmthead->pointer_to_song)-memstart);

fprintf(out,"\n");

fprintf(out," ; #### Instrument Pointer Table...\n");

// output the instrument pointers, which are consecutive words...

startrange=(rmthead->pointer_to_instrument_pointers)-memstart;

endrange=(rmthead->pointer_to_track_pointers_lo)-memstart;

for(t=startrange;t<endrange;t=t 2)

{

myupoint=(void *)(rmthead->magic) t;

if((myupoint->pointer)!=0)

fprintf(out," .word (.RMTSTART $x)\n",(myupoint->pointer) - memstart);

else

fprintf(out," .word ( $0000 )\n");

}

fprintf(out,"\n\n");

// output the track pointers, which are split into 2 separate LO and HI byte tables

fprintf(out," ; #### Track Pointer Table, Lo...\n");

startrange=(rmthead->pointer_to_track_pointers_lo)-memstart;

endrange=(rmthead->pointer_to_track_pointers_hi)-memstart;

for(t=startrange;t<endrange;t )

{

lo = buffer rmtstart t;

hi = buffer rmtstart t endrange-startrange;

if ((*lo == 0) && (*hi == 0)) // don't relocate 0x0000 flag

{

fprintf(out," .byte $00\n");

continue;

}

val = *lo (*hi << 8) - memstart;

fprintf(out," .byte <(.RMTSTART $x)\n",val);

}

fprintf(out,"\n");

fprintf(out," ; #### Track Pointer Table, Hi...\n");

startrange=(rmthead->pointer_to_track_pointers_lo)-memstart;

endrange=(rmthead->pointer_to_track_pointers_hi)-memstart;

for(t=startrange;t<endrange;t )

{

uint8_t *lo,*hi;

uint16_t val;

lo = buffer rmtstart t;

hi = buffer rmtstart t endrange-startrange;

if ((*lo == 0) && (*hi == 0)) // don't relocate 0x0000 flag

{

fprintf(out," .byte $00\n");

continue;

}

val = *lo (*hi << 8) - memstart;

fprintf(out," .byte >(.RMTSTART $x)\n",val);

}

fprintf(out,"\n");

fprintf(out," ; #### Track Instrument Data...\n");

startrange=endrange (endrange-startrange); // past the end of the trackpointer table

endrange=(rmthead->pointer_to_song)-memstart;

fprintf(out," .byte ");

i=0;

for(t=startrange;t<endrange;t )

{

if(i>0)

fprintf(out,",");

fprintf(out,"$x",buffer[t rmtstart]);

i ;

if((i==16)&&((t 2)<endrange))

{

fprintf(out,"\n .byte ");

i=0;

}

}

fprintf(out,"\n\n");

fprintf(out," ; #### Song Data...\n");

// ...

startrange=(rmthead->pointer_to_song)-memstart rmtstart;

endrange=size-2;

fprintf(out," .byte ");

i=0;

for(t=startrange;t<endrange;t )

{

// if the 4 byte command starts with 0xFE it's a GOTO

if( (buffer[t]==0xFE) && (!((t-startrange)&3)))

{

val = buffer[t 2] (buffer[t 3] << 8) - memstart;

fprintf(out,"\n");

fprintf(out," .word $XFE,(.RMTSTART $x) ; GOTO",buffer[t 1],val);

t=t 3;

i=16;

continue;

}

if((i==16)&&((t 1)<endrange))

{

fprintf(out,"\n .byte ");

i=0;

}

if(i>0)

fprintf(out,",");

fprintf(out,"$x",buffer[t]);

i ;

}

fprintf(out,"\n\n");

fclose(out);

}