/* chkmch.c */

/*
 *  Copyright (C) 2001-2026  Alan R. Baldwin
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Alan R. Baldwin
 * 721 Berkeley St.
 * Kent, Ohio  44240
 */

#include "asxxxx.h"
#include "chk.h"

char	*cpu	= "ASxxxx Test Assembler";
char	*dsft	= "asm";

/*
 * Opcode Cycle Definitions
 */
#define	OPCY_SDP	((char) (0xFF))
#define	OPCY_ERR	((char) (0xFE))

#define	OPCY_NONE	((char) (0x80))
#define	OPCY_MASK	((char) (0x7F))

#define	OPCY_CPU	((char) (OPCY_NONE | 0xFD))

#define	UN		((char) (OPCY_NONE | 0x00))


static char  chkpg1[256] = {
/*--*--* 0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F */
/*--*--* -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  - */
/*00*/   0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,
/*10*/  UN, 1,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,
/*20*/  UN,UN, 2,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,
/*30*/  UN,UN,UN, 3,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,
/*40*/  UN,UN,UN,UN, 4,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,
/*50*/  UN,UN,UN,UN,UN, 5,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,
/*60*/  UN,UN,UN,UN,UN,UN, 6,UN,UN,UN,UN,UN,UN,UN,UN,UN,
/*70*/  UN,UN,UN,UN,UN,UN,UN, 7,UN,UN,UN,UN,UN,UN,UN,UN,
/*80*/  UN,UN,UN,UN,UN,UN,UN,UN, 8,UN,UN,UN,UN,UN,UN,UN,
/*90*/  UN,UN,UN,UN,UN,UN,UN,UN,UN, 9,UN,UN,UN,UN,UN,UN,
/*A0*/  UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,10,UN,UN,UN,UN,UN,
/*B0*/  UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,11,UN,UN,UN,UN,
/*C0*/  UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,12,UN,UN,UN,
/*D0*/  UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,13,UN,UN,
/*E0*/  UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,14,UN,
/*F0*/  UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,UN,15
};

int	mchtyp;
struct	area *zpg;
/*
 * Process a machine op.
 */
void
machine(struct mne *mp)
{
	int c;
	a_uint op;
	struct expr e1;
	char id[NCPS];

	/*
	 * Using Internal Format
	 * For Cycle Counting
	 */
	opcycles = OPCY_NONE;

	clrexpr(&e1);
	op = mp->m_valu;
	switch (mp->m_type) {

	case S_CPU:
		opcycles = OPCY_CPU;
		mchtyp = (int) op;
		sym[2].s_addr = op;
		lmode = SLIST;
		break;

	case S_SDP:
		opcycles = OPCY_SDP;
		zpg = dot.s_area;
		if (more()) {
			expr(&e1);
			if (e1.e_flag == 0 && e1.e_base.e_ap == NULL) {
				if (e1.e_addr & 0xFF) {
					xerr('a', "A 256 Byte Boundary Required.");
				}
			}
			if ((c = getnb()) == ',') {
				getid(id, -1);
				zpg = alookup(id);
				if (zpg == NULL) {
					xerr('u', "Undefined Area.");
				}
			} else {
				unget(c);
			}
		}
		outdp(zpg, &e1, 0);
		lmode = SLIST;
		break;

	case S_BITS:
		exprmasks((int) mp->m_valu);
		lmode = SLIST;
		break;

	case S_OPCODE:
		expr(&e1);
		abscheck(&e1);
		outab(e1.e_addr);
		break;

	default:
		opcycles = OPCY_ERR;
		xerr('o', "Internal Opcode Error.");
		break;
	}

	if (opcycles == OPCY_NONE) {
		opcycles = chkpg1[cb[0] & 0xFF];
	}
 	/*
	 * Translate To External Format
	 */
	if (opcycles == OPCY_NONE) { opcycles  =  CYCL_NONE; } else
	if (opcycles  & OPCY_NONE) { opcycles |= (CYCL_NONE | 0x3F00); }

	/*
	 * Dumby Operation
	 */
	op += 1;
}

/*
 * Branch/Jump PCR Mode Check
 */
int
mchpcr(struct expr *esp, int *v, int n)
{
	if (esp->e_base.e_ap == dot.s_area) {
		if (v != NULL) {
#if 1
			/* Allows branching from top-to-bottom and bottom-to-top */
 			*v = (int) (esp->e_addr - dot.s_addr - n);
			/* only bits 'a_mask' are significant, make circular */
			if (*v & s_mask) {
				*v |= (int) ~a_mask;
			}
			else {
				*v &= (int) a_mask;
			}
#else
			/* Disallows branching from top-to-bottom and bottom-to-top */
			*v = (int) ((esp->e_addr & a_mask) - (dot.s_addr & a_mask) - n);
#endif
		}
		return(1);
	}
	if (esp->e_flag==0 && esp->e_base.e_ap==NULL) {
		/*
		 * Absolute Destination
		 *
		 * Use the global symbol '.__.ABS.'
		 * of value zero and force the assembler
		 * to use this absolute constant as the
		 * base value for the relocation.
		 */
		esp->e_flag = 1;
		esp->e_base.e_sp = &sym[1];
	}
	return(0);
}

/*
 * Machine dependent initialization
 */
void
minit(void)
{
	if (pass == 0) {
		hilo = 1;
		mchtyp = X_NOCPU;
		sym[2].s_addr = X_NOCPU;
	}

	/*
	 * Zero Page
	 */
	zpg = NULL;
}
