/****************************************************************************
* include/nxflat.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NXFLAT_H
#define __INCLUDE_NXFLAT_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define NXFLAT_MAX_STRING_SIZE 64 /* Largest size of string (w/zterminator) */
#define NXFLAT_MAGIC "NxFT" /* NXFLAT magic number */
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* The NXFLAT file header
*
* The elements within this structure are stored in network order (i.e.,
* ntohs() and ntohl() should be used to access fields within the
* header.
****************************************************************************/
struct nxflat_hdr_s
{
/* The "magic number" identifying the file type. This field should contain
* "NxFT". NOTE that there is no other versioning information other than
* this magic number.
*/
char h_magic[4];
/* The following fields provide the memory map for the nxflat binary.
*
* h_entry - Offset to the first executable insruction from
* the beginning of the file.
* h_datastart - Offset to the beginning of the data segment from
* the beginning of the file. This field can also
* interpreted as the size of the ISpace segment.
* h_dataend - Offset to the end of the data segment from the
* beginning of the file.
* h_bssend - Offset to the end of bss segment from the beginning
* of the file.
*
* The text segment can be considered to be the contiguous (unrelocated)
* address space range from address zero through (but not including)
* h_datastart.
*
* The size of the data/bss segment includes (as a minimum) the data
* and bss regions (bss_end - data_start) as well as the size of the
* stack. At run time, this region will also include program arguments
* and environment variables.
*
* The bss segment is data_end through bss_end.
*/
uint32_t h_entry;
uint32_t h_datastart;
uint32_t h_dataend;
uint32_t h_bssend;
/* Size of stack, in bytes */
uint32_t h_stacksize;
/* Relocation entries:
*
* h_relocstart - Offset to the beginning of an array of relocation
* records (struct nxflat_reloc). The offset is
* relative to the start of the file
*/
uint32_t h_relocstart; /* Offset of relocation records */
/* Imported symbol table (NOTE no symbols are exported):
*
* h_importsymbols - Offset to the beginning of an array of imported
* symbol structures (struct nxflat_import_s). The
* h_importsymbols offset is relative to the
* beginning of the file. Each entry of the
* array contains an uint32_t offset (again from
* the beginning of the file) to the name of
* a symbol string. This string is null-terminated.
*/
uint32_t h_importsymbols; /* Offset to list of imported symbols */
/* 16-bit counts
*
* h_reloccount - The number of relocation records in the array
* h_importcount - The number of records in the h_importsymbols array.
*/
uint16_t h_reloccount; /* Number of relocation records */
uint16_t h_importcount; /* Number of imported symbols */
};
/****************************************************************************
* NXFLAT Relocation types.
*
* The relocation records are an array of the following type.
****************************************************************************/
struct nxflat_reloc_s
{
uint32_t r_info; /* Bit-encoded relocation info */
};
/* Pack the type and the offset into one 32-bit value */
#define NXFLAT_RELOC(t,o) (((uint32_t)((t) & 3) << 30) | ((o) & 0x3fffffff))
/* The top three bits of the relocation info is the relocation type (see the
* NXFLAT_RELOC_TYPE_* definitions below. This is an unsigned value.
*/
#define NXFLAT_RELOC_TYPE(r) ((uint32_t)(r) >> 30)
/* The bottom 28 bits of the relocation info is the (non-negative) offset
* into the D-Space that needs the fixup.
*/
#define NXFLAT_RELOC_OFFSET(r) ((uint32_t)(r) & 0x3fffffff)
/* These are possible values for the relocation type:
*
* NXFLAT_RELOC_TYPE_REL32I Meaning: Object file contains a 32-bit offset
* into I-Space at the offset.
* Fixup: Add mapped I-Space address to the
* offset.
* NXFLAT_RELOC_TYPE_REL32D Meaning: Object file contains a 32-bit offset
* into D-Space at the offset.
* Fixup: Add allocated D-Space address to the
* offset.
* NXFLAT_RELOC_TYPE_REL32ID Meaning: Object file contains a 32-bit offset
* into I-Space at the offset that will
* unfortunately be references relative
* to the GOT
* Fixup: Add allocated the mapped I-Space
* address MINUS the allocated D-Space
* address to the offset.
*/
#define NXFLAT_RELOC_TYPE_REL32I 0
#define NXFLAT_RELOC_TYPE_REL32D 1
#undef NXFLAT_RELOC_TYPE_REL32ID /* May not need */
#define NXFLAT_RELOC_TYPE_NUM 2 /* Number of relocation types */
/****************************************************************************
* NXFLAT Imported symbol type
*
* The imported symbols are an array of the following type. The fields
* in each element are stored in native machine order.
****************************************************************************/
struct nxflat_import_s
{
uint32_t i_funcname; /* Offset to name of imported function */
uint32_t i_funcaddress; /* Resolved address of imported function */
};
#endif /* __INCLUDE_NXFLAT_H */