px4-firmware/misc/pascal/insn16/libinsn/preloc.c

150 lines
4.6 KiB
C

/**********************************************************************
* preloc.c
* Perform P-Code relocations
*
* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
**********************************************************************/
/**********************************************************************
* Included Files
**********************************************************************/
#include <stdint.h>
#include "keywords.h"
#include "pdefs.h"
#include "pedefs.h"
#include "podefs.h"
#include "pinsn16.h"
#include "pofflib.h"
#include "perr.h"
#include "pinsn.h"
/**********************************************************************
* Definitions
**********************************************************************/
/**********************************************************************
* Private Type Definitions
**********************************************************************/
/**********************************************************************
* Private Function Prototypes
**********************************************************************/
/**********************************************************************
* Global Variables
**********************************************************************/
/**********************************************************************
* Private Variables
**********************************************************************/
/**********************************************************************
* Private Functions
**********************************************************************/
int insn_Relocate(OPTYPE *op, uint32_t pcOffset, uint32_t roOffset)
{
switch (op->op)
{
/* Catch each instruction that references the read-only data
* section.
*/
case oLAC:
/* Add the offset to the read-only data section */
op->arg2 += roOffset;
break;
/* Catch each instruction that references the text section
* data via an offset.
*/
case oPCAL: /* Procedure / Function calls */
case oJMP: /* Unconditional jump */
case oJEQUZ: /* Jump on unary comparisons with zero */
case oJNEQZ:
case oJLTZ:
case oJGTEZ:
case oJGTZ:
case oJLTEZ:
case oJEQU: /* Jump on binary comparisons */
case oJNEQ:
case oJLT:
case oJGTE:
case oJGT:
case oJLTE:
/* Add the offset to the text section */
op->arg2 += pcOffset;
break;
/* Return an end of file indication if oEND encountered */
case oEND:
return 1;
/* Otherwise, it is not an interesting opcode */
default:
break;
}
/* Return 0 on all opcodes other than oEND */
return 0;
}
/***********************************************************************/
void insn_FixupProcedureCall(uint8_t *progData, uint32_t symValue)
{
/* Sanity checking */
if (progData[0] != oPCAL)
fatal(ePOFFCONFUSION);
if (symValue > 0xffff)
fatal(eBADSHORTINT);
/* Perform the relocation */
progData[2] = symValue >> 8;
progData[3] = symValue & 0xff;
}
/***********************************************************************/