view lwasm/os9.c @ 352:fd96bb4a9c8d lwtools-4.11

Remove manual building targets from Makefile Since the manual is distributed prebuilt in the repository, there is no need to include documentation building rules in the top level make file.
author William Astle <lost@l-w.ca>
date Mon, 13 Apr 2015 13:18:38 -0600
parents 244f1227f2b5
children 8764142b3192
line wrap: on
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/*
os9.c
Copyright © 2009 William Astle

This file is part of LWASM.

LWASM 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/>.


This file implements the various pseudo operations related to OS9 target
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <lw_expr.h>

#include "lwasm.h"
#include "instab.h"


// OS9 syscall
PARSEFUNC(pseudo_parse_os9)
{
	lw_expr_t e;
	
	if (as -> output_format != OUTPUT_OS9 && as -> output_format != OUTPUT_OBJ)
	{
		lwasm_register_error(as, l, "os9 directive only valid for OS9 target");
		return;
	}
	
	// fetch immediate value
	e = lwasm_parse_expr(as, p);
	if (!e)
	{
		lwasm_register_error(as, l, "Bad operand");
		return;
	}
	lwasm_save_expr(l, 0, e);
	l -> len = 3;
}

EMITFUNC(pseudo_emit_os9)
{
	lw_expr_t e;
	
	e = lwasm_fetch_expr(l, 0);

	lwasm_emitop(l, 0x103f);
	lwasm_emitexpr(l, e, 1);
}

PARSEFUNC(pseudo_parse_mod)
{
	lw_expr_t e;
	int i;
	
	if (as -> output_format != OUTPUT_OS9)
	{
		lwasm_register_error(as, l,  "mod directive only valid for OS9 target");
		skip_operand(p);
		return;
	}
	
	if (as -> inmod)
	{
		lwasm_register_error(as, l,  "Already in a module!");
		skip_operand(p);
		return;
	}

	// parse 6 expressions...
	for (i = 0; i < 5; i++)
	{
		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, "Bad operand");
			return;
		}

		lwasm_save_expr(l, i, e);

		if (**p != ',')
		{
			lwasm_register_error(as, l, "Bad operand");
			return;
		}
		(*p)++;
	}

	e = lwasm_parse_expr(as, p);
	if (!e)
	{
		lwasm_register_error(as, l, "Bad operand");
		return;
	}
	lwasm_save_expr(l, 5, e);

	l -> inmod = 1;
	
	// we have an implicit ORG 0 with "mod"
	lw_expr_destroy(l -> addr);
	l -> addr = lw_expr_build(lw_expr_type_int, 0);

	// likewise for data pointer
	lw_expr_destroy(l -> daddr);
	l -> daddr = lw_expr_build(lw_expr_type_int, 0);

	// init crc
	as -> inmod = 1;
	
	l -> len = 13;
}

EMITFUNC(pseudo_emit_mod)
{
	lw_expr_t e1, e2, e3, e4;
	int csum;
	
	as -> crc[0] = 0xff;
	as -> crc[1] = 0xff;
	as -> crc[2] = 0xff;

	// sync bytes
	lwasm_emit(l, 0x87);
	lwasm_emit(l, 0xcd);
	
	// mod length
	lwasm_emitexpr(l, e1 = lwasm_fetch_expr(l, 0), 2);
	
	// name offset
	lwasm_emitexpr(l, e2 = lwasm_fetch_expr(l, 1), 2);
	
	// type
	lwasm_emitexpr(l, e3 = lwasm_fetch_expr(l, 2), 1);
	
	// flags/rev
	lwasm_emitexpr(l, e4 = lwasm_fetch_expr(l, 3), 1);
	
	// header check
	csum = ~(0x87 ^ 0xCD ^(lw_expr_intval(e1) >> 8) ^ (lw_expr_intval(e1) & 0xff)
		^ (lw_expr_intval(e2) >> 8) ^ (lw_expr_intval(e2) & 0xff)
		^ lw_expr_intval(e3) ^ lw_expr_intval(e4));
	lwasm_emit(l, csum);

	// module type specific output
	// note that these are handled the same for all so
	// there need not be any special casing
	
	// exec offset or fmgr name offset
	lwasm_emitexpr(l, lwasm_fetch_expr(l, 4), 2);
	
	// data size or drvr name offset
	lwasm_emitexpr(l, lwasm_fetch_expr(l, 5), 2);
}

PARSEFUNC(pseudo_parse_emod)
{
	skip_operand(p);
	if (as -> output_format != OUTPUT_OS9)
	{
		lwasm_register_error(as, l, "emod directive only valid for OS9 target");
		return;
	}
	
	if (!(as -> inmod))
	{
		lwasm_register_error(as, l, "not in a module!");
		return;
	}
	
	as -> inmod = 0;
	l -> len = 3;
}

EMITFUNC(pseudo_emit_emod)
{
	unsigned char tcrc[3];
	
	// don't mess with CRC!
	tcrc[0] = as -> crc[0] ^ 0xff;
	tcrc[1] = as -> crc[1] ^ 0xff;
	tcrc[2] = as -> crc[2] ^ 0xff;
	lwasm_emit(l, tcrc[0]);
	lwasm_emit(l, tcrc[1]);
	lwasm_emit(l, tcrc[2]);
}