xref: /openbmc/u-boot/include/environment.h (revision 4c15ef55)
1 /*
2  * (C) Copyright 2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #ifndef _ENVIRONMENT_H_
25 #define _ENVIRONMENT_H_	1
26 
27 /**************************************************************************
28  *
29  * The "environment" is stored as a list of '\0' terminated
30  * "name=value" strings. The end of the list is marked by a double
31  * '\0'. New entries are always added at the end. Deleting an entry
32  * shifts the remaining entries to the front. Replacing an entry is a
33  * combination of deleting the old value and adding the new one.
34  *
35  * The environment is preceeded by a 32 bit CRC over the data part.
36  *
37  **************************************************************************
38  */
39 
40 #if defined(CFG_ENV_IS_IN_FLASH)
41 # ifndef  CFG_ENV_ADDR
42 #  define CFG_ENV_ADDR	(CFG_FLASH_BASE + CFG_ENV_OFFSET)
43 # endif
44 # ifndef  CFG_ENV_OFFSET
45 #  define CFG_ENV_OFFSET (CFG_ENV_ADDR - CFG_FLASH_BASE)
46 # endif
47 # if !defined(CFG_ENV_ADDR_REDUND) && defined(CFG_ENV_OFFSET_REDUND)
48 #  define CFG_ENV_ADDR_REDUND	(CFG_FLASH_BASE + CFG_ENV_OFFSET_REDUND)
49 # endif
50 # if defined(CFG_ENV_SECT_SIZE) || defined(CFG_ENV_SIZE)
51 #  ifndef  CFG_ENV_SECT_SIZE
52 #   define CFG_ENV_SECT_SIZE	CFG_ENV_SIZE
53 #  endif
54 #  ifndef  CFG_ENV_SIZE
55 #   define CFG_ENV_SIZE	CFG_ENV_SECT_SIZE
56 #  endif
57 # else
58 #  error "Both CFG_ENV_SECT_SIZE and CFG_ENV_SIZE undefined"
59 # endif
60 # if defined(CFG_ENV_ADDR_REDUND) && !defined(CFG_ENV_SIZE_REDUND)
61 #  define CFG_ENV_SIZE_REDUND	CFG_ENV_SIZE
62 # endif
63 # if (CFG_ENV_ADDR >= CFG_MONITOR_BASE) && \
64      (CFG_ENV_ADDR+CFG_ENV_SIZE) <= (CFG_MONITOR_BASE + CFG_MONITOR_LEN)
65 #  define ENV_IS_EMBEDDED	1
66 # endif
67 # if defined(CFG_ENV_ADDR_REDUND) || defined(CFG_ENV_OFFSET_REDUND)
68 #  define CFG_REDUNDAND_ENVIRONMENT	1
69 # endif
70 #endif	/* CFG_ENV_IS_IN_FLASH */
71 
72 #if defined(CFG_ENV_IS_IN_NAND)
73 # ifndef CFG_ENV_OFFSET
74 #  error "Need to define CFG_ENV_OFFSET when using CFG_ENV_IS_IN_NAND"
75 # endif
76 # ifndef CFG_ENV_SIZE
77 #  error "Need to define CFG_ENV_SIZE when using CFG_ENV_IS_IN_NAND"
78 # endif
79 # ifdef CFG_ENV_OFFSET_REDUND
80 #  define CFG_REDUNDAND_ENVIRONMENT
81 # endif
82 #endif /* CFG_ENV_IS_IN_NAND */
83 
84 
85 #ifdef CFG_REDUNDAND_ENVIRONMENT
86 # define ENV_HEADER_SIZE	(sizeof(unsigned long) + 1)
87 #else
88 # define ENV_HEADER_SIZE	(sizeof(unsigned long))
89 #endif
90 
91 
92 #define ENV_SIZE (CFG_ENV_SIZE - ENV_HEADER_SIZE)
93 
94 typedef	struct environment_s {
95 	unsigned long	crc;		/* CRC32 over data bytes	*/
96 #ifdef CFG_REDUNDAND_ENVIRONMENT
97 	unsigned char	flags;		/* active/obsolete flags	*/
98 #endif
99 	unsigned char	data[ENV_SIZE]; /* Environment data		*/
100 } env_t;
101 
102 #endif	/* _ENVIRONMENT_H_ */
103