1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2002-2003  David McCullough <davidm@snapgear.com>
4  * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
5  *                          The Silver Hammer Group, Ltd.
6  *
7  * This file provides the definitions and structures needed to
8  * support uClinux flat-format executables.
9  */
10 #ifndef _LINUX_FLAT_H
11 #define _LINUX_FLAT_H
12 
13 #define	FLAT_VERSION			0x00000004L
14 
15 /*
16  * To make everything easier to port and manage cross platform
17  * development,  all fields are in network byte order.
18  */
19 
20 struct flat_hdr {
21 	char	magic[4];
22 	__be32	rev;          /* version (as above) */
23 	__be32	entry;        /* Offset of first executable instruction
24 				 with text segment from beginning of file */
25 	__be32	data_start;   /* Offset of data segment from beginning of
26 				 file */
27 	__be32	data_end;     /* Offset of end of data segment from beginning
28 				 of file */
29 	__be32	bss_end;      /* Offset of end of bss segment from beginning
30 				 of file */
31 
32 	/* (It is assumed that data_end through bss_end forms the bss segment.) */
33 
34 	__be32	stack_size;   /* Size of stack, in bytes */
35 	__be32	reloc_start;  /* Offset of relocation records from beginning of
36 				 file */
37 	__be32	reloc_count;  /* Number of relocation records */
38 	__be32	flags;
39 	__be32	build_date;   /* When the program/library was built */
40 	__u32	filler[5];    /* Reservered, set to zero */
41 };
42 
43 #define FLAT_FLAG_RAM    0x0001 /* load program entirely into RAM */
44 #define FLAT_FLAG_GOTPIC 0x0002 /* program is PIC with GOT */
45 #define FLAT_FLAG_GZIP   0x0004 /* all but the header is compressed */
46 #define FLAT_FLAG_GZDATA 0x0008 /* only data/relocs are compressed (for XIP) */
47 #define FLAT_FLAG_KTRACE 0x0010 /* output useful kernel trace for debugging */
48 
49 /*
50  * While it would be nice to keep this header clean,  users of older
51  * tools still need this support in the kernel.  So this section is
52  * purely for compatibility with old tool chains.
53  *
54  * DO NOT make changes or enhancements to the old format please,  just work
55  *        with the format above,  except to fix bugs with old format support.
56  */
57 
58 #define	OLD_FLAT_VERSION			0x00000002L
59 #define OLD_FLAT_RELOC_TYPE_TEXT	0
60 #define OLD_FLAT_RELOC_TYPE_DATA	1
61 #define OLD_FLAT_RELOC_TYPE_BSS		2
62 
63 typedef union {
64 	u32		value;
65 	struct {
66 #if defined(__LITTLE_ENDIAN_BITFIELD) || \
67     (defined(mc68000) && !defined(CONFIG_COLDFIRE))
68 		s32	offset : 30;
69 		u32	type : 2;
70 # elif defined(__BIG_ENDIAN_BITFIELD)
71 		u32	type : 2;
72 		s32	offset : 30;
73 # else
74 #   	error "Unknown bitfield order for flat files."
75 # endif
76 	} reloc;
77 } flat_v2_reloc_t;
78 
79 #endif /* _LINUX_FLAT_H */
80