/****************************************************************************
* pexec.h
*
* Copyright (C) 2008 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.
*
****************************************************************************/
#ifndef __PEXEC_H
#define __PEXEC_H
/****************************************************************************
* Included Files
****************************************************************************/
/****************************************************************************
* Definitions
****************************************************************************/
#define BPERI 2
#define ITOBSTACK(i) ((i) << 1)
#define BTOISTACK(i) ((i) >> 1)
#define ROUNDBTOI(i) (((i) + 1) >> 1)
/****************************************************************************
* Type Definitions
****************************************************************************/
typedef uint32 ustack_t; /* Stack values are 16-bits in length */
typedef sint32 sstack_t;
typedef uint32 addr_t; /* Addresses are 16-bits in length */
typedef uint16 level_t; /* Limits to MAXUINT16 levels */
union stack_u
{
ustack_t *i;
ubyte *b;
};
typedef union stack_u stackType;
/* This structure describes the parameters needed to initialize the p-code
* interpreter.
*/
struct pexec_attr_s
{
/* Instruction space (I-Space) */
FAR ubyte *ispace; /* Allocated I-Space containing p-code data */
addr_t entry; /* Entry point */
addr_t maxpc; /* Last valid p-code address */
/* Read-only data block */
FAR ubyte *rodata; /* Address of read-only data block */
addr_t rosize; /* Size of read-only data block */
/* Allocate for variable storage */
addr_t varsize; /* Variable storage size */
addr_t strsize; /* String storage size */
};
/* This structure defines the current state of the p-code interpreter */
struct pexec_s
{
/* This is the emulated P-Machine stack (D-Space) */
stackType dstack;
/* This is the emulated P-Machine instruction space (I-Space) */
FAR ubyte *ispace;
/* Address of last valid P-Code */
addr_t maxpc;
/* These are the emulated P-Machine registers:
*
* spb: Base of the stack
* sp: The Pascal stack pointer
* lsp: Level stack pointer
* csp: The current top of the stack used to manage string
* storage
* fp: Base Register of the current stack frame. Holds the address
* of the base of the stack frame of the current block.
* fop: Pointer to section containing read-only data
* pc: Holds the current p-code location
*/
addr_t spb; /* Pascal stack base */
addr_t sp; /* Pascal stack pointer */
addr_t lsp; /* Level stack pointer */
addr_t csp; /* Character stack pointer */
addr_t fp; /* Base of the current frame */
addr_t rop; /* Read-only data pointer */
addr_t pc; /* Program counter */
/* Info needed to perform a simulated reset */
addr_t strsize; /* String stack size */
addr_t rosize; /* Read-only stack size */
addr_t entry; /* Entry point */
addr_t stacksize; /* (debug only) */
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
EXTERN FAR struct pexec_s *pload(const char *filename, addr_t varsize, addr_t strsize);
EXTERN FAR struct pexec_s *pexec_init(struct pexec_attr_s *attr);
EXTERN int pexec(FAR struct pexec_s *st);
EXTERN void pexec_reset(struct pexec_s *st);
EXTERN void pexec_release(struct pexec_s *st);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __PEXEC_H */
