3 * Reinhard Meyer, reinhard.meyer@emk-elektronik.de
5 * General Purpose Backup Registers
6 * Based on AT91SAM9XE datasheet
8 * SPDX-License-Identifier: GPL-2.0+
15 * The Atmel AT91SAM9 series has a small resource of 4 nonvolatile
16 * 32 Bit registers (buffered by the Vbu power).
18 * Please consider carefully before using this resource for tasks
19 * that do not really need nonvolatile registers. Maybe you can
20 * store information in EEPROM or FLASH instead.
22 * However, if you use a GPBR please document its use here and
23 * reference the define in your code!
25 * known typical uses of the GPBRs:
26 * GPBR[0]: offset for RTT timekeeping (u-boot, kernel)
29 * GPBR[3]: bootcount (u-boot)
31 #define AT91_GPBR_INDEX_TIMEOFF 0
32 #define AT91_GPBR_INDEX_BOOTCOUNT 3
36 typedef struct at91_gpbr {
40 #endif /* __ASSEMBLY__ */