Re: [PATCH 1/2] bootcount: add bootcount flash driver

Am 22.04.20 um 12:46 schrieb Arnaud Ferraris:

In order to save the bootcounter on raw flash device, this commit introduces a new bootcount driver, enabled using the CONFIG_BOOTCOUNT_FLASH option.

The bootcounter is stored at address CONFIG_SYS_BOOTCOUNT_FLASH_ADDR (absolute address, can also be computed from CONFIG_SYS_BOOTCOUNT_FLASH_OFFSET), and it uses a data structure providing several useful enhancements:

• a `flags` field, used to check whether the bootcounter should be written to flash (similar to the `upgrade_available` environment variable)
• a `crc` field to ensure integrity of the structure, which will be used later on when adding redundancy support
• a `data` field, which can be used to store and pass user data between u-boot and the OS (e.g boot partition selection)

Signed-off-by: Arnaud Ferraris arnaud.ferraris@collabora.com

drivers/bootcount/Kconfig | 14 ++++++ drivers/bootcount/Makefile | 1 + drivers/bootcount/bootcount_flash.c | 78 +++++++++++++++++++++++++++++ include/bootcount.h | 12 +++++ scripts/config_whitelist.txt | 2 + 5 files changed, 107 insertions(+) create mode 100644 drivers/bootcount/bootcount_flash.c

diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig index 0e506c9ea2..94de3f5ef8 100644 --- a/drivers/bootcount/Kconfig +++ b/drivers/bootcount/Kconfig @@ -66,6 +66,20 @@ config BOOTCOUNT_I2C CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for the bootcounter.

+config BOOTCOUNT_FLASH

• bool "Boot counter on flash device"
• help

•  Store the bootcounter on raw flash. The bootcounter will be stored
  

•  as a structure using one flash sector, and will only be written when
  

•  a specific flag is set in the structure. Additionnally, this driver
  

•  relies on one of the following to be defined:
  

•  CONFIG_SYS_BOOTCOUNT_FLASH_ADDR = address used for storing the
  

•                                    bootcounter on flash.
  

•    or
  

•  CONFIG_SYS_BOOTCOUNT_FLASH_OFFSET = bootcounter offset on flash
  

•                                      (relative to SYS_FLASH_BASE).
  

config BOOTCOUNT_AT91 bool "Boot counter for Atmel AT91SAM9XE" depends on AT91SAM9XE diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile index 73ccfb5a08..bddcd136f3 100644 --- a/drivers/bootcount/Makefile +++ b/drivers/bootcount/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_BOOTCOUNT_RAM) += bootcount_ram.o obj-$(CONFIG_BOOTCOUNT_ENV) += bootcount_env.o obj-$(CONFIG_BOOTCOUNT_I2C) += bootcount_i2c.o obj-$(CONFIG_BOOTCOUNT_EXT) += bootcount_ext.o +obj-$(CONFIG_BOOTCOUNT_FLASH) += bootcount_flash.o

obj-$(CONFIG_DM_BOOTCOUNT) += bootcount-uclass.o obj-$(CONFIG_DM_BOOTCOUNT_RTC) += rtc.o diff --git a/drivers/bootcount/bootcount_flash.c b/drivers/bootcount/bootcount_flash.c new file mode 100644 index 0000000000..1222bb4ae0 --- /dev/null +++ b/drivers/bootcount/bootcount_flash.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • Copyright (c) 2020 Collabora Ltd. All rights reserved.
• */

+#include <bootcount.h> +#include <common.h> +#include <asm/io.h> +#include <u-boot/crc.h> +#include <flash.h>

+#ifndef CONFIG_SYS_BOOTCOUNT_FLASH_ADDR +# ifdef CONFIG_SYS_BOOTCOUNT_FLASH_OFFSET +# define CONFIG_SYS_BOOTCOUNT_FLASH_ADDR \

• (CONFIG_SYS_FLASH_BASE + CONFIG_SYS_BOOTCOUNT_FLASH_OFFSET)
  

+# else +# error "Either CONFIG_SYS_BOOTCOUNT_FLASH_ADDR or " \

•   "CONFIG_SYS_BOOTCOUNT_FLASH_OFFSET should be defined!"
  

+# endif +#endif

+#define BOOTCOUNT_CRC_SIZE (sizeof(*bootcount) - sizeof(bootcount->crc))

+static struct bootcount *bootcount = (void *)CONFIG_SYS_BOOTCOUNT_ADDR; +static ulong bc_flash = CONFIG_SYS_BOOTCOUNT_FLASH_ADDR; +static ulong bc_flash_end =

• CONFIG_SYS_BOOTCOUNT_FLASH_ADDR + CONFIG_SYS_FLASH_SECT_SIZE - 1;

+static void bootcount_write(void) +{

• if (flash_sect_protect(0, bc_flash, bc_flash_end))

• return;
  

• puts("Erasing Flash...\n");
• if (flash_sect_erase(bc_flash, bc_flash_end))

• return;
  

• puts("Writing bootcount to Flash...\n");
• if (flash_write((char *)bootcount, bc_flash, sizeof(*bootcount)))

• return;
  

• flash_sect_protect(1, bc_flash, bc_flash_end);

Why don't you build this on top of the MTD layer to make it compatible with all flash media types? Nowadays no one uses parallel NOR flash devices anymore ;)

Also why don't you continously write new entries until the sector is full? Erasing the sector on every boot kills the flash sector early.

+}

+static void bootcount_init(void) +{

• memset(bootcount, 0, sizeof(*bootcount));
• bootcount->magic = CONFIG_SYS_BOOTCOUNT_MAGIC;
• bootcount->crc = crc32(0, (uchar *)bootcount, BOOTCOUNT_CRC_SIZE);
• bootcount_write();

+}

+void bootcount_store(ulong a) +{

• bootcount->count = a;
• bootcount->crc = crc32(0, (uchar *)bootcount, BOOTCOUNT_CRC_SIZE);
• if (bootcount->flags & BOOTCOUNT_FLAGS_UPDATE)

• bootcount_write();
  

+}

+ulong bootcount_load(void) +{

• static int initialized;
• u32 crc;
• if (!initialized) {

• memcpy(bootcount, (void *)bc_flash, sizeof(*bootcount));
  

• initialized = 1;
  

• }
• crc = crc32(0, (uchar *)bootcount, BOOTCOUNT_CRC_SIZE);
• if (bootcount->magic != CONFIG_SYS_BOOTCOUNT_MAGIC ||

•    bootcount->crc != crc) {
  

• bootcount_init();
  

• }
• return bootcount->count;

+} diff --git a/include/bootcount.h b/include/bootcount.h index cd30403984..5698bd3239 100644 --- a/include/bootcount.h +++ b/include/bootcount.h @@ -79,6 +79,18 @@ ulong bootcount_load(void); # endif #endif

+#ifdef CONFIG_BOOTCOUNT_FLASH +struct bootcount {

• u32 magic;
• u32 count;
• u32 flags;
• u32 data;
• u32 crc;

+};

+#define BOOTCOUNT_FLAGS_UPDATE 0x1 +#endif

#ifdef CONFIG_SYS_BOOTCOUNT_LE static inline void raw_bootcount_store(volatile u32 *addr, u32 data) { diff --git a/scripts/config_whitelist.txt b/scripts/config_whitelist.txt index 6908431d03..672483f040 100644 --- a/scripts/config_whitelist.txt +++ b/scripts/config_whitelist.txt @@ -1829,6 +1829,8 @@ CONFIG_SYS_BOARD_NAME CONFIG_SYS_BOARD_OMAP3_HA CONFIG_SYS_BOOK3E_HV CONFIG_SYS_BOOTCOUNT_BE +CONFIG_SYS_BOOTCOUNT_FLASH_ADDR +CONFIG_SYS_BOOTCOUNT_FLASH_OFFSET CONFIG_SYS_BOOTCOUNT_LE CONFIG_SYS_BOOTFILE_PREFIX CONFIG_SYS_BOOTMAPSZ