//----------------------------------------------------------------
//	newipl86.cpp	
//
//	This utility creates 'boilerplate' source-text for a new
//	bootsector program, written in 'as86' assembly language. 
//
//		usage:	$ newipl86 <appname>
//
//	programmer: ALLAN CRUSE
//	written on: 10 FEB 2004 
//----------------------------------------------------------------

#include <stdio.h>	// for fprintf(), fopen(), etc
#include <string.h>	// for strncpy(), strncat()
#include <time.h>	// for time(), localtime()

char authorname[] = "ALLAN CRUSE"; // substitute YOUR name 
char monthlist[] = "JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC";

int main( int argc, char *argv[] )
{
	// check for module-name as command-line argument
	if ( argc == 1 ) 
		{
		fprintf( stderr, "Must specify module-name\n" );
		return	-1;
		}

	// prepare program name 
	char	appname[33] = "";
	strncpy( appname, argv[1], 28 );

	// prepare code-file name
	char	srcname[33] = "";
	strncpy( srcname, argv[1], 28 );
	strncat( srcname, ".s", 22 );

	// announce this program's purpose 
	printf( "\nCreating skeleton for program " );
	printf( "named \'%s\' \n", srcname );

	// insure source-file doesn't already exist
	FILE	*fp = fopen( srcname, "rb" );
	if ( fp != NULL )
		{
		fclose( fp );
		fprintf( stderr, "File \'%s\' already exists\n", srcname );
		return	-1;
		}

	// create the new source-file
	fp = fopen( srcname, "wb" );
	if ( fp == NULL )
		{
		fprintf( stderr, "Cannot create source-file\n" );
		return	-1;
		}

	// obtain today's date (in DD MMM YYYY format)
	time_t		now = time( (time_t *)NULL );
	struct tm	*t = localtime( &now );
	char	month[4] = "";
	strncpy( month, monthlist+3*t->tm_mon, 3 );
	month[3] = '\0';

	char	when[16] = "";
	sprintf( when, "%02d %3s %04d", t->tm_mday, month, 1900+t->tm_year );	

	char	border[68] = "";
	memset( border, '-', 65 );

	fprintf( fp, ";//%s\n", border+2 );
	fprintf( fp, ";//\t%s\n", srcname );
	fprintf( fp, ";//\n" );
	fprintf( fp, ";//\n" );
	fprintf( fp, ";//\n" );
	fprintf( fp, ";//\t   assemble with:  " );
	fprintf( fp, "$ as86 %s -b %s.b \n", srcname, appname );
	fprintf( fp, ";//\t   install using:  " );
	fprintf( fp, "$ dd if=%s.b of=/dev/fd0 \n", appname );
	fprintf( fp, ";//\n" );
	fprintf( fp, ";//\tNOTE: This code begins executing " );
	fprintf( fp, "with CS:IP = 0000:7C00. \n" );
	fprintf( fp, ";//\n" );
	fprintf( fp, ";//\tprogrammer: %s\n", authorname );
	fprintf( fp, ";//\tdate begun: %s\n", when );
	fprintf( fp, ";//%s\n", border+2 );

	fprintf( fp, "\n" );
	fprintf( fp, "\n\t.SECT\t.TEXT\n" );
	fprintf( fp, ";%s\n", border );
	fprintf( fp, "start:" );
	fprintf( fp, "\tcli\t\t\t\t" );
	fprintf( fp, "; enter critical section \n" );

	fprintf( fp, "\tmov\tax, cs\t\t\t" );
	fprintf( fp, ";  address zero segment \n" );	
	fprintf( fp, "\tmov\tss, ax\t\t\t" );
	fprintf( fp, ";    with SS register   \n" );	
	fprintf( fp, "\tmov\tsp, #0x7C00\t\t" );
	fprintf( fp, ";  stacktop at BOOT_LOCN \n" );	

	fprintf( fp, "\tsti\t\t\t\t" );
	fprintf( fp, "; leave critical section \n" );
	
	fprintf( fp, "\tjmpf\t#main, #0x07C0\t\t" );
	fprintf( fp, "; re-normalize CS and IP \n" );
	fprintf( fp, ";%s\n", border );

	fprintf( fp, ";%s\n", border );
	fprintf( fp, "main:\t \n" );
	fprintf( fp, "\t; setup sement-registers " );
	fprintf( fp, "to address our program data \n" );
	fprintf( fp, "\n" );
	fprintf( fp, "\tmov\tax, cs \t\t\t; address this segment \n" );
	fprintf( fp, "\tmov\tds, ax \t\t\t;   with DS register   \n" );
	fprintf( fp, "\tmov\tes, ax \t\t\t;   also ES register   \n" );
	fprintf( fp, "\n" );
	fprintf( fp, "\n\t; await user keypress \n" );
	fprintf( fp, "\n" );
	fprintf( fp, "\txor\tah, ah \t\t\t; get_keyboard_input \n" );
	fprintf( fp, "\tint\t0x16 \t\t\t; invoke BIOS service \n" );
	fprintf( fp, "\tint\t0x19 \t\t\t; then reboot machine \n" );
	fprintf( fp, ";%s\n", border );

	fprintf( fp, ";%s\n", border );
	fprintf( fp, "\t.ORG\t510\t\t\t; boot-signature's offset \n " );
	fprintf( fp, "\t.BYTE\t0x55, 0xAA\t\t; value of boot-signature \n " );
	fprintf( fp, ";%s\n", border );
	fprintf( fp, "\tEND\n" );

	printf( "\n" );
}