3 * Reinhard Meyer, reinhard.meyer@emk-elektronik.de
5 * General Purpose Backup Registers
6 * Based on AT91SAM9XE datasheet
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
18 * The Atmel AT91SAM9 series has a small resource of 4 nonvolatile
19 * 32 Bit registers (buffered by the Vbu power).
21 * Please consider carefully before using this resource for tasks
22 * that do not really need nonvolatile registers. Maybe you can
23 * store information in EEPROM or FLASH instead.
25 * However, if you use a GPBR please document its use here and
26 * reference the define in your code!
28 * known typical uses of the GPBRs:
29 * GPBR[0]: offset for RTT timekeeping (u-boot, kernel)
32 * GPBR[3]: bootcount (u-boot)
34 #define AT91_GPBR_INDEX_TIMEOFF 0
35 #define AT91_GPBR_INDEX_BOOTCOUNT 3
39 typedef struct at91_gpbr {
43 #endif /* __ASSEMBLY__ */