If no softreset save registers are found on the hardware "bootcount" is stored in the environment. To prevent a saveenv on all reboots, the environment variable "upgrade_available" is introduced. If "upgrade_available" is 0, "bootcount" is always 0 therefore no need to save the environment on u-boot boot, if "upgrade_available" is 1 "bootcount" is incremented in the environment and environment gets written on u-boot start. So the Userspace Applikation must set the "upgrade_available" and "bootcount" variable to 0 (for example with fw_setenv), if a boot was successfully.
Signed-off-by: Heiko Schocher hs@denx.de
--- - changes for v3 rebase against current u-boot/master 509dca7a11aad394d781a9d31a7bfa6692562741 - changes for v2 none --- README | 16 ++++++++++++++++ drivers/bootcount/Makefile | 1 + drivers/bootcount/bootcount_env.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+) create mode 100644 drivers/bootcount/bootcount_env.c
diff --git a/README b/README index d06e7a0..1aeae7e 100644 --- a/README +++ b/README @@ -784,6 +784,22 @@ The following options need to be configured: as a convenience, when switching between booting from RAM and NFS.
+- Bootcount: + CONFIG_BOOTCOUNT_LIMIT + Implements a mechanism for detecting a repeating reboot + cycle, see: + http://www.denx.de/wiki/view/DULG/UBootBootCountLimit + + CONFIG_BOOTCOUNT_ENV + If no softreset save registers are found on the hardware + "bootcount" is stored in the environment. To prevent a + saveenv on all reboots, the environment variable + "upgrade_available" is used. If "upgrade_available" is + 0, "bootcount" is always 0, if "upgrade_available" is + 1 "bootcount" is incremented in the environment. + So the Userspace Applikation must set the "upgrade_available" + and "bootcount" variable to 0, if a boot was successfully. + - Pre-Boot Commands: CONFIG_PREBOOT
diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile index 2b517b6..8ec0423 100644 --- a/drivers/bootcount/Makefile +++ b/drivers/bootcount/Makefile @@ -11,6 +11,7 @@ COBJS-$(CONFIG_AT91SAM9XE) += bootcount_at91.o COBJS-$(CONFIG_BLACKFIN) += bootcount_blackfin.o COBJS-$(CONFIG_SOC_DA8XX) += bootcount_davinci.o COBJS-$(CONFIG_BOOTCOUNT_RAM) += bootcount_ram.o +COBJS-$(CONFIG_BOOTCOUNT_ENV) += bootcount_env.o
COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/bootcount/bootcount_env.c b/drivers/bootcount/bootcount_env.c new file mode 100644 index 0000000..2d6e8db --- /dev/null +++ b/drivers/bootcount/bootcount_env.c @@ -0,0 +1,29 @@ +/* + * (C) Copyright 2013 + * Heiko Schocher, DENX Software Engineering, hs@denx.de. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> + +void bootcount_store(ulong a) +{ + int upgrade_available = getenv_ulong("upgrade_available", 10, 0); + + if (upgrade_available) { + setenv_ulong("bootcount", a); + saveenv(); + } +} + +ulong bootcount_load(void) +{ + int upgrade_available = getenv_ulong("upgrade_available", 10, 0); + ulong val = 0; + + if (upgrade_available) + val = getenv_ulong("bootcount", 10, 0); + + return val; +}