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/****************************************************************************
* libnxflat/lib/nxflat_stack.c
*
* Copyright (C) 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 <nuttx/config.h>
#include <sys/types.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/nxflat.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxflat_adjuststacksize
****************************************************************************/
void nxflat_adjuststacksize(struct nxflat_loadinfo_s *load_info,
int argc, int envc, int system_usage)
{
uint32 total_usage = system_usage;
/* For argc, we will store the array (argc elements), the argc
* value itself, plus a null pointer.
*/
total_usage += (argc + 2) * sizeof(uint32);
/* For envc, we will store the array (envc elements) plus a null
* pointer.
*/
total_usage += (envc + 1) * sizeof(uint32);
/* And we will store six additional words described the memory
* layout.
*/
total_usage += 6 * sizeof(uint32);
/* Add this to the previously determined stack size */
load_info->stack_size += total_usage;
}
/****************************************************************************
* Name: nxflat_initstack
*
* Description:
* When we enter the NXFLAT_ loader, it will expect to see a stack frame
* like the following. NOTE: This logic assumes a push down stack
* (i.e., we decrement the stack pointer to go from the "BOTTOM" to
* the "TOP").
*
*
* TOP->argc Argument count (integer)
* argv[0...(argc-1)] Program arguments (pointers)
* NULL Marks end of arguments
* env[0...N] Environment variables (pointers)
* NULL Marks end of environment variables
* loader ispace Address of loader ISpace (NXFLAT_ header)
* loader dspace Address of loader DSpace
* loader dspace size Size of the allocated loader DSpace
* program ispace Address of program ISpace (NXFLAT_ header)
* program dspace Address of program DSpace
* BOTTOM->program dspace size Size of the allocated program DSpace
*
****************************************************************************/
uint32 nxflat_initstack(struct nxflat_loadinfo_s *prog_load_info,
struct nxflat_loadinfo_s *lib_load_info,
int argc, int envc, char *p)
{
uint32 *argv;
uint32 *envp;
uint32 *sp;
char dummy;
/* p points to the beginning of the array of arguments;
* sp points to the "bottom" of a push down stack.
*/
sp = (uint32*)((-(uint32)sizeof(char*))&(uint32) p);
/* Place program information on the stack */
if (prog_load_info)
{
*sp-- = (uint32)prog_load_info->dspace_size;
*sp-- = (uint32)prog_load_info->dspace;
*sp-- = (uint32)prog_load_info->ispace;
}
else
{
dbg("No program load info provided\n");
return -EINVAL;
}
/* Place loader information on the stack */
if (lib_load_info)
{
*sp-- = (uint32)lib_load_info->dspace_size;
*sp-- = (uint32)lib_load_info->dspace;
*sp-- = (uint32)lib_load_info->ispace;
}
else
{
*sp-- = (uint32)0;
*sp-- = (uint32)0;
*sp-- = (uint32)0;
}
/* Allocate space on the stack for the envp array contents
* (including space for a null terminator).
*/
sp -= envc+1;
envp = sp;
/* Allocate space on the stack for the argv array contents
* (including space for a null terminator).
*/
sp -= argc+1;
argv = sp;
/* Put argc on the stack. sp now points to the "top" of the
* stack as it will be received by the new task.
*/
*sp-- = (uint32)argc;
/* Copy argv pointers into the stack frame (terminated with
* a null pointer).
*/
prog_load_info->arg_start = (uint32)p;
while (argc-->0)
{
/* Put the address of the beginning of the string */
*argv++ = (uint32)p;
/* Search for the end of the string */
do
{
dummy = *p++;
}
while (dummy);
}
*argv = (uint32)NULL,argv;
/* Copy envp pointers into the stack frame (terminated with
* a null pointer).
*/
prog_load_info->env_start = (uint32)p;
while (envc-->0)
{
/* Put the address of the beginning of the string */
*envp++ = (uint32)p;
/* Search for the end of the string */
do
{
dummy = *p++;
}
while (dummy);
}
*envp = (uint32)NULL;
prog_load_info->env_end = (uint32)p;
return (uint32)sp;
}
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