In the FWU Multi Bank Update feature, the information about the updatable images is stored as part of the metadata, which is stored on a dedicated partition. Add the metadata structure, and a driver model uclass which provides functions to access the metadata. These are generic API's, and implementations can be added based on parameters like how the metadata partition is accessed and what type of storage device houses the metadata.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- Changes since V5: * Change the parameter to the function fwu_plat_get_alt_num to pass the FWU udevice pointer instead of passing the metadata device directly.

drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/fwu-mdata/Kconfig | 7 + drivers/fwu-mdata/Makefile | 6 + drivers/fwu-mdata/fwu-mdata-uclass.c | 458 +++++++++++++++++++++++++++ include/dm/uclass-id.h | 1 + include/fwu.h | 49 +++ include/fwu_mdata.h | 67 ++++ 8 files changed, 591 insertions(+) create mode 100644 drivers/fwu-mdata/Kconfig create mode 100644 drivers/fwu-mdata/Makefile create mode 100644 drivers/fwu-mdata/fwu-mdata-uclass.c create mode 100644 include/fwu.h create mode 100644 include/fwu_mdata.h

diff --git a/drivers/Kconfig b/drivers/Kconfig index b26ca8cf70..adc6079ecf 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -42,6 +42,8 @@ source "drivers/firmware/Kconfig"

source "drivers/fpga/Kconfig"

+source "drivers/fwu-mdata/Kconfig" + source "drivers/gpio/Kconfig"

source "drivers/hwspinlock/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 67c8af7442..901150bb35 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -83,6 +83,7 @@ obj-y += cache/ obj-$(CONFIG_CPU) += cpu/ obj-y += crypto/ obj-$(CONFIG_FASTBOOT) += fastboot/ +obj-$(CONFIG_DM_FWU_MDATA) += fwu-mdata/ obj-y += misc/ obj-$(CONFIG_MMC) += mmc/ obj-$(CONFIG_NVME) += nvme/ diff --git a/drivers/fwu-mdata/Kconfig b/drivers/fwu-mdata/Kconfig new file mode 100644 index 0000000000..d6a21c8e19 --- /dev/null +++ b/drivers/fwu-mdata/Kconfig @@ -0,0 +1,7 @@ +config DM_FWU_MDATA + bool "Driver support for accessing FWU Metadata" + depends on DM + help + Enable support for accessing FWU Metadata partitions. The + FWU Metadata partitions reside on the same storage device + which contains the other FWU updatable firmware images. diff --git a/drivers/fwu-mdata/Makefile b/drivers/fwu-mdata/Makefile new file mode 100644 index 0000000000..e53a8c9983 --- /dev/null +++ b/drivers/fwu-mdata/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# +# Copyright (c) 2022, Linaro Limited +# + +obj-$(CONFIG_DM_FWU_MDATA) += fwu-mdata-uclass.o diff --git a/drivers/fwu-mdata/fwu-mdata-uclass.c b/drivers/fwu-mdata/fwu-mdata-uclass.c new file mode 100644 index 0000000000..2092fcfc23 --- /dev/null +++ b/drivers/fwu-mdata/fwu-mdata-uclass.c @@ -0,0 +1,458 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2022, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <efi_loader.h> +#include <fwu.h> +#include <fwu_mdata.h> +#include <log.h> +#include <malloc.h> + +#include <linux/errno.h> +#include <linux/types.h> +#include <u-boot/crc.h> + +#define IMAGE_ACCEPT_SET BIT(0) +#define IMAGE_ACCEPT_CLEAR BIT(1) + +static int fwu_get_dev_ops(struct udevice **dev, + const struct fwu_mdata_ops **ops) +{ + int ret; + + ret = uclass_get_device(UCLASS_FWU_MDATA, 0, dev); + if (ret) { + log_debug("Cannot find fwu device\n"); + return ret; + } + + if ((*ops = device_get_ops(*dev)) == NULL) { + log_debug("Cannot get fwu device ops\n"); + return -ENOSYS; + } + + return 0; +} + +/** + * fwu_verify_mdata() - Verify the FWU metadata + * @mdata: FWU metadata structure + * @pri_part: FWU metadata partition is primary or secondary + * + * Verify the FWU metadata by computing the CRC32 for the metadata + * structure and comparing it against the CRC32 value stored as part + * of the structure. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_verify_mdata(struct fwu_mdata *mdata, bool pri_part) +{ + u32 calc_crc32; + void *buf; + + buf = &mdata->version; + calc_crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32)); + + if (calc_crc32 != mdata->crc32) { + log_err("crc32 check failed for %s FWU metadata partition\n", + pri_part ? "primary" : "secondary"); + return -1; + } + + return 0; +} + +/** + * fwu_get_active_index() - Get active_index from the FWU metadata + * @active_idx: active_index value to be read + * + * Read the active_index field from the FWU metadata and place it in + * the variable pointed to be the function argument. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_get_active_index(u32 *active_idx) +{ + int ret; + struct fwu_mdata *mdata = NULL; + + ret = fwu_get_mdata(&mdata); + if (ret < 0) { + log_err("Unable to get valid FWU metadata\n"); + goto out; + } + + /* + * Found the FWU metadata partition, now read the active_index + * value + */ + *active_idx = mdata->active_index; + if (*active_idx > CONFIG_FWU_NUM_BANKS - 1) { + log_err("Active index value read is incorrect\n"); + ret = -EINVAL; + } + +out: + free(mdata); + + return ret; +} + +/** + * fwu_update_active_index() - Update active_index from the FWU metadata + * @active_idx: active_index value to be updated + * + * Update the active_index field in the FWU metadata + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_update_active_index(u32 active_idx) +{ + int ret; + struct fwu_mdata *mdata = NULL; + + if (active_idx > CONFIG_FWU_NUM_BANKS - 1) { + log_err("Active index value to be updated is incorrect\n"); + return -1; + } + + ret = fwu_get_mdata(&mdata); + if (ret < 0) { + log_err("Unable to get valid FWU metadata\n"); + goto out; + } + + /* + * Update the active index and previous_active_index fields + * in the FWU metadata + */ + mdata->previous_active_index = mdata->active_index; + mdata->active_index = active_idx; + + /* + * Now write this updated FWU metadata to both the + * FWU metadata partitions + */ + ret = fwu_update_mdata(mdata); + if (ret < 0) { + log_err("Failed to update FWU metadata partitions\n"); + ret = -EIO; + } + +out: + free(mdata); + + return ret; +} + +/** + * fwu_get_image_alt_num() - Get the dfu alt number to be used for capsule update + * @image_type_id: pointer to the image guid as passed in the capsule + * @update_bank: Bank to which the update is to be made + * @alt_num: The alt_num for the image + * + * Based on the guid value passed in the capsule, along with the bank to which the + * image needs to be updated, get the dfu alt number which will be used for the + * capsule update + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_get_image_alt_num(efi_guid_t *image_type_id, u32 update_bank, + int *alt_num) +{ + int ret, i; + efi_guid_t *image_guid; + struct udevice *dev = NULL; + struct fwu_mdata *mdata = NULL; + struct fwu_image_entry *img_entry; + const struct fwu_mdata_ops *ops = NULL; + struct fwu_image_bank_info *img_bank_info; + + ret = fwu_get_dev_ops(&dev, &ops); + if (ret) + return ret; + + ret = fwu_get_mdata(&mdata); + if (ret) { + log_err("Unable to get valid FWU metadata\n"); + goto out; + } + + /* + * The FWU metadata has been read. Now get the image_uuid for the + * image with the update_bank. + */ + for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) { + if (!guidcmp(image_type_id, + &mdata->img_entry[i].image_type_uuid)) { + img_entry = &mdata->img_entry[i]; + img_bank_info = &img_entry->img_bank_info[update_bank]; + image_guid = &img_bank_info->image_uuid; + ret = fwu_plat_get_alt_num(dev, image_guid, alt_num); + break; + } + } + + if (i == CONFIG_FWU_NUM_IMAGES_PER_BANK) { + log_err("Partition with the image type %pUs not found\n", + image_type_id); + ret = -EINVAL; + goto out; + } + + if (!ret) { + log_debug("alt_num %d for partition %pUs\n", + *alt_num, image_guid); + } else { + log_err("alt_num not found for partition with GUID %pUs\n", + image_guid); + ret = -EINVAL; + } + +out: + free(mdata); + + return ret; +} + +/** + * fwu_mdata_check() - Check if the FWU metadata is valid + * + * Validate both copies of the FWU metadata. If one of the copies + * has gone bad, restore it from the other bad copy. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_mdata_check(void) +{ + int ret; + struct udevice *dev = NULL; + const struct fwu_mdata_ops *ops = NULL; + + ret = fwu_get_dev_ops(&dev, &ops); + if (ret) + return ret; + + if (!ops->mdata_check) { + log_err("mdata_check() method not defined\n"); + return -ENOSYS; + } + + return ops->mdata_check(dev); +} + +/** + * fwu_revert_boot_index() - Revert the active index in the FWU metadata + * + * Revert the active_index value in the FWU metadata, by swapping the values + * of active_index and previous_active_index in both copies of the + * FWU metadata. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_revert_boot_index(void) +{ + int ret; + u32 cur_active_index; + struct fwu_mdata *mdata = NULL; + + ret = fwu_get_mdata(&mdata); + if (ret < 0) { + log_err("Unable to get valid FWU metadata\n"); + goto out; + } + + /* + * Swap the active index and previous_active_index fields + * in the FWU metadata + */ + cur_active_index = mdata->active_index; + mdata->active_index = mdata->previous_active_index; + mdata->previous_active_index = cur_active_index; + + /* + * Now write this updated FWU metadata to both the + * FWU metadata partitions + */ + ret = fwu_update_mdata(mdata); + if (ret < 0) { + log_err("Failed to update FWU metadata partitions\n"); + ret = -EIO; + } + +out: + free(mdata); + + return ret; +} + +/** + * fwu_set_clear_image_accept() - Set or Clear the Acceptance bit for the image + * @img_type_id: Guid of the image type for which the accepted bit is to be + * set or cleared + * @bank: Bank of which the image's Accept bit is to be set or cleared + * @action: Action which specifies whether image's Accept bit is to be set or + * cleared + * + * Set/Clear the accepted bit for the image specified by the img_guid parameter. + * This indicates acceptance or rejection of image for subsequent boots by some + * governing component like OS(or firmware). + * + * Return: 0 if OK, -ve on error + * + */ +static int fwu_set_clear_image_accept(efi_guid_t *img_type_id, + u32 bank, u8 action) +{ + int ret, i; + u32 nimages; + struct fwu_mdata *mdata = NULL; + struct fwu_image_entry *img_entry; + struct fwu_image_bank_info *img_bank_info; + + ret = fwu_get_mdata(&mdata); + if (ret < 0) { + log_err("Unable to get valid FWU metadata\n"); + goto out; + } + + nimages = CONFIG_FWU_NUM_IMAGES_PER_BANK; + img_entry = &mdata->img_entry[0]; + for (i = 0; i < nimages; i++) { + if (!guidcmp(&img_entry[i].image_type_uuid, img_type_id)) { + img_bank_info = &img_entry[i].img_bank_info[bank]; + if (action == IMAGE_ACCEPT_SET) + img_bank_info->accepted |= FWU_IMAGE_ACCEPTED; + else + img_bank_info->accepted = 0; + + ret = fwu_update_mdata(mdata); + goto out; + } + } + + /* Image not found */ + ret = -EINVAL; + +out: + free(mdata); + + return ret; +} + +/** + * fwu_accept_image() - Set the Acceptance bit for the image + * @img_type_id: Guid of the image type for which the accepted bit is to be + * cleared + * @bank: Bank of which the image's Accept bit is to be set + * + * Set the accepted bit for the image specified by the img_guid parameter. This + * indicates acceptance of image for subsequent boots by some governing component + * like OS(or firmware). + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_accept_image(efi_guid_t *img_type_id, u32 bank) +{ + return fwu_set_clear_image_accept(img_type_id, bank, + IMAGE_ACCEPT_SET); +} + +/** + * fwu_clear_accept_image() - Clear the Acceptance bit for the image + * @img_type_id: Guid of the image type for which the accepted bit is to be + * cleared + * @bank: Bank of which the image's Accept bit is to be cleared + * + * Clear the accepted bit for the image type specified by the img_type_id parameter. + * This function is called after the image has been updated. The accepted bit is + * cleared to be set subsequently after passing the image acceptance criteria, by + * either the OS(or firmware) + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank) +{ + return fwu_set_clear_image_accept(img_type_id, bank, + IMAGE_ACCEPT_CLEAR); +} + +/** + * fwu_get_mdata() - Get a FWU metadata copy + * @mdata: Copy of the FWU metadata + * + * Get a valid copy of the FWU metadata. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_get_mdata(struct fwu_mdata **mdata) +{ + int ret; + struct udevice *dev = NULL; + const struct fwu_mdata_ops *ops = NULL; + + ret = fwu_get_dev_ops(&dev, &ops); + if (ret) + return ret; + + if (!ops->get_mdata) { + log_err("get_mdata() method not defined\n"); + return -ENOSYS; + } + + return ops->get_mdata(dev, mdata); +} + +/** + * fwu_update_mdata() - Update the FWU metadata + * @mdata: Copy of the FWU metadata + * + * Update the FWU metadata structure by writing to the + * FWU metadata partitions. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_update_mdata(struct fwu_mdata *mdata) +{ + int ret; + void *buf; + struct udevice *dev = NULL; + const struct fwu_mdata_ops *ops = NULL; + + ret = fwu_get_dev_ops(&dev, &ops); + if (ret) + return ret; + + if (!ops->update_mdata) { + log_err("get_mdata() method not defined\n"); + return -ENOSYS; + } + + /* + * Calculate the crc32 for the updated FWU metadata + * and put the updated value in the FWU metadata crc32 + * field + */ + buf = &mdata->version; + mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32)); + + return ops->update_mdata(dev, mdata); +} + +UCLASS_DRIVER(fwu_mdata) = { + .id = UCLASS_FWU_MDATA, + .name = "fwu-mdata", +}; diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 3ba69ad9a0..7da719c048 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -57,6 +57,7 @@ enum uclass_id { UCLASS_ETH_PHY, /* Ethernet PHY device */ UCLASS_FIRMWARE, /* Firmware */ UCLASS_FS_FIRMWARE_LOADER, /* Generic loader */ + UCLASS_FWU_MDATA, /* FWU Metadata Access */ UCLASS_GPIO, /* Bank of general-purpose I/O pins */ UCLASS_HASH, /* Hash device */ UCLASS_HWSPINLOCK, /* Hardware semaphores */ diff --git a/include/fwu.h b/include/fwu.h new file mode 100644 index 0000000000..e03cfff800 --- /dev/null +++ b/include/fwu.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2022, Linaro Limited + */ + +#if !defined _FWU_H_ +#define _FWU_H_ + +#include <blk.h> +#include <efi.h> + +#include <linux/types.h> + +struct fwu_mdata; +struct udevice; + +/** + * @mdata_check: check the validity of the FWU metadata partitions + * @get_mdata() - Get a FWU metadata copy + * @update_mdata() - Update the FWU metadata copy + */ +struct fwu_mdata_ops { + int (*mdata_check)(struct udevice *dev); + + int (*get_mdata)(struct udevice *dev, struct fwu_mdata **mdata); + + int (*update_mdata)(struct udevice *dev, struct fwu_mdata *mdata); +}; + +#define FWU_MDATA_VERSION 0x1 + +#define FWU_MDATA_GUID \ + EFI_GUID(0x8a7a84a0, 0x8387, 0x40f6, 0xab, 0x41, \ + 0xa8, 0xb9, 0xa5, 0xa6, 0x0d, 0x23) + +int fwu_get_mdata(struct fwu_mdata **mdata); +int fwu_update_mdata(struct fwu_mdata *mdata); +int fwu_get_active_index(u32 *active_idx); +int fwu_update_active_index(u32 active_idx); +int fwu_get_image_alt_num(efi_guid_t *image_type_id, u32 update_bank, + int *alt_num); +int fwu_mdata_check(void); +int fwu_revert_boot_index(void); +int fwu_accept_image(efi_guid_t *img_type_id, u32 bank); +int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank); + +int fwu_plat_get_alt_num(struct udevice *dev, efi_guid_t *image_guid, + int *alt_num); +#endif /* _FWU_H_ */ diff --git a/include/fwu_mdata.h b/include/fwu_mdata.h new file mode 100644 index 0000000000..72e3edab43 --- /dev/null +++ b/include/fwu_mdata.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2022, Linaro Limited + */ + +#if !defined _FWU_MDATA_H_ +#define _FWU_MDATA_H_ + +#include <efi.h> + +/** + * struct fwu_image_bank_info - firmware image information + * @image_uuid: Guid value of the image in this bank + * @accepted: Acceptance status of the image + * @reserved: Reserved + * + * The structure contains image specific fields which are + * used to identify the image and to specify the image's + * acceptance status + */ +struct fwu_image_bank_info { + efi_guid_t image_uuid; + uint32_t accepted; + uint32_t reserved; +} __attribute__((__packed__)); + +/** + * struct fwu_image_entry - information for a particular type of image + * @image_type_uuid: Guid value for identifying the image type + * @location_uuid: Guid of the storage volume where the image is located + * @img_bank_info: Array containing properties of images + * + * This structure contains information on various types of updatable + * firmware images. Each image type then contains an array of image + * information per bank. + */ +struct fwu_image_entry { + efi_guid_t image_type_uuid; + efi_guid_t location_uuid; + struct fwu_image_bank_info img_bank_info[CONFIG_FWU_NUM_BANKS]; +} __attribute__((__packed__)); + +/** + * struct fwu_mdata - FWU metadata structure for multi-bank updates + * @crc32: crc32 value for the FWU metadata + * @version: FWU metadata version + * @active_index: Index of the bank currently used for booting images + * @previous_active_inde: Index of the bank used before the current bank + * being used for booting + * @img_entry: Array of information on various firmware images that can + * be updated + * + * This structure is used to store all the needed information for performing + * multi bank updates on the platform. This contains info on the bank being + * used to boot along with the information needed for identification of + * individual images + */ +struct fwu_mdata { + uint32_t crc32; + uint32_t version; + uint32_t active_index; + uint32_t previous_active_index; + + struct fwu_image_entry img_entry[CONFIG_FWU_NUM_IMAGES_PER_BANK]; +} __attribute__((__packed__)); + +#endif /* _FWU_MDATA_H_ */

The FWU metadata structure is accessed through the driver model interface. On the stm32mp157c-dk2 board, the FWU metadata is stored on the uSD card. Add the fwu-mdata node on the u-boot specifc dtsi file for accessing the metadata structure.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Patrick Delaunay patrick.delaunay@foss.st.com --- Changes since V5: None

arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi b/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi index 06ef3a4095..24f86209db 100644 --- a/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi +++ b/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi @@ -4,3 +4,10 @@ */

#include "stm32mp157a-dk1-u-boot.dtsi" + +/ { + fwu-mdata { + compatible = "u-boot,fwu-mdata-gpt"; + fwu-mdata-store = <&sdmmc1>; + }; +};

The FWU Multi Bank Update feature supports updation of firmware images to one of multiple sets(also called banks) of images. The firmware images are clubbed together in banks, with the system booting images from the active bank. Information on the images such as which bank they belong to is stored as part of the metadata structure, which is stored on the same storage media as the firmware images on a dedicated partition.

At the time of update, the metadata is read to identify the bank to which the images need to be flashed(update bank). On a successful update, the metadata is modified to set the updated bank as active bank to subsequently boot from.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- Changes since V5: * Use u"TrialStateCtr" as suggested by Patrick

include/fwu.h | 10 ++ lib/Kconfig | 6 + lib/Makefile | 1 + lib/efi_loader/efi_capsule.c | 231 ++++++++++++++++++++++++++++++++++- lib/efi_loader/efi_setup.c | 3 +- lib/fwu_updates/Kconfig | 31 +++++ lib/fwu_updates/Makefile | 3 +- lib/fwu_updates/fwu.c | 26 ++++ 8 files changed, 304 insertions(+), 7 deletions(-) create mode 100644 lib/fwu_updates/Kconfig

diff --git a/include/fwu.h b/include/fwu.h index b374fd1179..7ff1cd75d3 100644 --- a/include/fwu.h +++ b/include/fwu.h @@ -32,13 +32,23 @@ struct fwu_mdata_ops { };

#define FWU_MDATA_VERSION 0x1 +#define FWU_IMAGE_ACCEPTED 0x1

#define FWU_MDATA_GUID \ EFI_GUID(0x8a7a84a0, 0x8387, 0x40f6, 0xab, 0x41, \ 0xa8, 0xb9, 0xa5, 0xa6, 0x0d, 0x23)

+#define FWU_OS_REQUEST_FW_REVERT_GUID \ + EFI_GUID(0xacd58b4b, 0xc0e8, 0x475f, 0x99, 0xb5, \ + 0x6b, 0x3f, 0x7e, 0x07, 0xaa, 0xf0) + +#define FWU_OS_REQUEST_FW_ACCEPT_GUID \ + EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \ + 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8) + u8 fwu_update_checks_pass(void); int fwu_boottime_checks(void); +int fwu_trial_state_ctr_start(void);

int fwu_get_mdata(struct fwu_mdata **mdata); int fwu_update_mdata(struct fwu_mdata *mdata); diff --git a/lib/Kconfig b/lib/Kconfig index acc0ac081a..4ca6ea226b 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -966,3 +966,9 @@ config PHANDLE_CHECK_SEQ phandles in fdtdec_get_alias_seq() function.

endmenu + +menu "FWU Multi Bank Updates" + +source lib/fwu_updates/Kconfig + +endmenu diff --git a/lib/Makefile b/lib/Makefile index d9b1811f75..0cf8527c2d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_EFI) += efi/ obj-$(CONFIG_EFI_LOADER) += efi_driver/ obj-$(CONFIG_EFI_LOADER) += efi_loader/ obj-$(CONFIG_CMD_BOOTEFI_SELFTEST) += efi_selftest/ +obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu_updates/ obj-$(CONFIG_LZMA) += lzma/ obj-$(CONFIG_BZIP2) += bzip2/ obj-$(CONFIG_TIZEN) += tizen/ diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c index a6b98f066a..18a356ba08 100644 --- a/lib/efi_loader/efi_capsule.c +++ b/lib/efi_loader/efi_capsule.c @@ -14,6 +14,7 @@ #include <env.h> #include <fdtdec.h> #include <fs.h> +#include <fwu.h> #include <hang.h> #include <malloc.h> #include <mapmem.h> @@ -32,6 +33,17 @@ static const efi_guid_t efi_guid_firmware_management_capsule_id = EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID; const efi_guid_t efi_guid_firmware_management_protocol = EFI_FIRMWARE_MANAGEMENT_PROTOCOL_GUID; +const efi_guid_t fwu_guid_os_request_fw_revert = + FWU_OS_REQUEST_FW_REVERT_GUID; +const efi_guid_t fwu_guid_os_request_fw_accept = + FWU_OS_REQUEST_FW_ACCEPT_GUID; + +#define FW_ACCEPT_OS (u32)0x8000 + +__maybe_unused static u32 update_index; +__maybe_unused static bool capsule_update; +__maybe_unused static bool fw_accept_os; +static bool image_index_check = true;

#ifdef CONFIG_EFI_CAPSULE_ON_DISK /* for file system access */ @@ -205,7 +217,8 @@ efi_fmp_find(efi_guid_t *image_type, u8 image_index, u64 instance, log_debug("+++ desc[%d] index: %d, name: %ls\n", j, desc->image_index, desc->image_id_name); if (!guidcmp(&desc->image_type_id, image_type) && - (desc->image_index == image_index) && + (!image_index_check || + desc->image_index == image_index) && (!instance || !desc->hardware_instance || desc->hardware_instance == instance)) @@ -388,6 +401,87 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s } #endif /* CONFIG_EFI_CAPSULE_AUTHENTICATE */

+static bool fwu_empty_capsule(struct efi_capsule_header *capsule) +{ + return !guidcmp(&capsule->capsule_guid, + &fwu_guid_os_request_fw_revert) || + !guidcmp(&capsule->capsule_guid, + &fwu_guid_os_request_fw_accept); +} + +static efi_status_t fwu_empty_capsule_process( + struct efi_capsule_header *capsule) +{ + int status; + u32 active_idx; + efi_status_t ret; + efi_guid_t *image_guid; + + if (!guidcmp(&capsule->capsule_guid, + &fwu_guid_os_request_fw_revert)) { + /* + * One of the previously updated image has + * failed the OS acceptance test. OS has + * requested to revert back to the earlier + * boot index + */ + status = fwu_revert_boot_index(); + if (status < 0) { + log_err("Failed to revert the FWU boot index\n"); + if (status == -ENODEV || + status == -ERANGE || + status == -EIO) + ret = EFI_DEVICE_ERROR; + else if (status == -EINVAL) + ret = EFI_INVALID_PARAMETER; + else + ret = EFI_OUT_OF_RESOURCES; + } else { + ret = EFI_SUCCESS; + log_err("Reverted the FWU active_index. Recommend rebooting the system\n"); + } + } else { + /* + * Image accepted by the OS. Set the acceptance + * status for the image. + */ + image_guid = (void *)(char *)capsule + + capsule->header_size; + + status = fwu_get_active_index(&active_idx); + if (status < 0) { + log_err("Unable to get the active_index from the FWU metadata\n"); + if (status == -ENODEV || + status == -ERANGE || + status == -EIO) + ret = EFI_DEVICE_ERROR; + else if (status == -EINVAL) + ret = EFI_INVALID_PARAMETER; + else + ret = EFI_OUT_OF_RESOURCES; + + return ret; + } + + status = fwu_accept_image(image_guid, active_idx); + if (status < 0) { + log_err("Unable to set the Accept bit for the image %pUs\n", + image_guid); + if (status == -ENODEV || + status == -ERANGE || + status == -EIO) + ret = EFI_DEVICE_ERROR; + else if (status == -EINVAL) + ret = EFI_INVALID_PARAMETER; + else + ret = EFI_OUT_OF_RESOURCES; + } else { + ret = EFI_SUCCESS; + } + } + + return ret; +}

/** * efi_capsule_update_firmware - update firmware from capsule @@ -407,10 +501,42 @@ static efi_status_t efi_capsule_update_firmware( void *image_binary, *vendor_code; efi_handle_t *handles; efi_uintn_t no_handles; - int item; + int item, alt_no; struct efi_firmware_management_protocol *fmp; u16 *abort_reason; + efi_guid_t image_type_id; efi_status_t ret = EFI_SUCCESS; + int status; + u8 image_index; + + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) { + if (!fwu_empty_capsule(capsule_data) && + !fwu_update_checks_pass()) { + log_err("FWU checks failed. Cannot start update\n"); + return EFI_INVALID_PARAMETER; + } + + if (fwu_empty_capsule(capsule_data)) { + capsule_update = false; + return fwu_empty_capsule_process(capsule_data); + } else { + capsule_update = true; + } + + /* Obtain the update_index from the platform */ + status = fwu_plat_get_update_index(&update_index); + if (status < 0) { + log_err("Failed to get the FWU update_index value\n"); + return EFI_DEVICE_ERROR; + } + + fw_accept_os = capsule_data->flags & FW_ACCEPT_OS ? 0x1 : 0x0; + /* + * For Multi Bank updates, the image index is determined at + * runtime based on the value of the update bank. + */ + image_index_check = false; + }

/* sanity check */ if (capsule_data->header_size < sizeof(*capsule) || @@ -485,8 +611,36 @@ static efi_status_t efi_capsule_update_firmware( goto out; }

+ if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) { + /* + * Based on the value of update_image_type_id, + * derive the alt number value. This will be + * passed as update_image_index to the + * set_image function. + */ + image_type_id = image->update_image_type_id; + status = fwu_get_image_alt_num(&image_type_id, + update_index, + &alt_no); + if (status < 0) { + log_err("Unable to get the alt no for the image type %pUs\n", + &image_type_id); + if (status == -ENODEV || status == -EIO) + ret = EFI_DEVICE_ERROR; + else if (status == -ENOMEM) + ret = EFI_OUT_OF_RESOURCES; + else if (status == -ERANGE || status == -EINVAL) + ret = EFI_INVALID_PARAMETER; + goto out; + } + log_debug("alt_no %u for Image Type Id %pUs\n", + alt_no, &image_type_id); + image_index = alt_no + 1; + } else { + image_index = image->update_image_index; + } abort_reason = NULL; - ret = EFI_CALL(fmp->set_image(fmp, image->update_image_index, + ret = EFI_CALL(fmp->set_image(fmp, image_index, image_binary, image_binary_size, vendor_code, NULL, @@ -497,6 +651,38 @@ static efi_status_t efi_capsule_update_firmware( efi_free_pool(abort_reason); goto out; } + + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) { + if (!fw_accept_os) { + /* + * The OS will not be accepting the firmware + * images. Set the accept bit of all the + * images contained in this capsule. + */ + status = fwu_accept_image(&image_type_id, + update_index); + } else { + status = fwu_clear_accept_image(&image_type_id, + update_index); + } + + if (status < 0) { + log_err("Unable to %s the accept bit for the image %pUs\n", + fw_accept_os ? "clear" : "set", + &image_type_id); + if (status == -ENODEV || status == -EIO) + ret = EFI_DEVICE_ERROR; + else if (status == -ENOMEM) + ret = EFI_OUT_OF_RESOURCES; + else if (status == -ERANGE || status == -EINVAL) + ret = EFI_INVALID_PARAMETER; + goto out; + } + log_debug("%s the accepted bit for Image %pUs\n", + fw_accept_os ? "Cleared" : "Set", + &image_type_id); + } + }

out: @@ -1102,8 +1288,10 @@ efi_status_t efi_launch_capsules(void) { struct efi_capsule_header *capsule = NULL; u16 **files; + int status; unsigned int nfiles, index, i; efi_status_t ret; + bool update_status = true;

if (check_run_capsules() != EFI_SUCCESS) return EFI_SUCCESS; @@ -1131,12 +1319,14 @@ efi_status_t efi_launch_capsules(void) ret = efi_capsule_read_file(files[i], &capsule); if (ret == EFI_SUCCESS) { ret = efi_capsule_update_firmware(capsule); - if (ret != EFI_SUCCESS) + if (ret != EFI_SUCCESS) { log_err("Applying capsule %ls failed.\n", files[i]); - else + update_status = false; + } else { log_info("Applying capsule %ls succeeded.\n", files[i]); + }

/* create CapsuleXXXX */ set_capsule_result(index, capsule, ret); @@ -1144,6 +1334,7 @@ efi_status_t efi_launch_capsules(void) free(capsule); } else { log_err("Reading capsule %ls failed\n", files[i]); + update_status = false; } /* delete a capsule either in case of success or failure */ ret = efi_capsule_delete_file(files[i]); @@ -1151,7 +1342,37 @@ efi_status_t efi_launch_capsules(void) log_err("Deleting capsule %ls failed\n", files[i]); } + efi_capsule_scan_done(); + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) { + if (update_status == true && capsule_update == true) { + /* + * All the capsules have been updated successfully, + * update the FWU metadata. + */ + log_debug("Update Complete. Now updating active_index to %u\n", + update_index); + status = fwu_update_active_index(update_index); + if (status < 0) { + log_err("Failed to update FWU metadata index values\n"); + if (status == -EINVAL || status == -ERANGE) + ret = EFI_INVALID_PARAMETER; + else if (status == -ENODEV || status == -EIO) + ret = EFI_DEVICE_ERROR; + else if (status == -ENOMEM) + ret = EFI_OUT_OF_RESOURCES; + } else { + log_debug("Successfully updated the active_index\n"); + status = fwu_trial_state_ctr_start(); + if (status < 0) + ret = EFI_DEVICE_ERROR; + else + ret = EFI_SUCCESS; + } + } else if (capsule_update == true && update_status == false) { + log_err("All capsules were not updated. Not updating FWU metadata\n"); + } + }

for (i = 0; i < nfiles; i++) free(files[i]); diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c index 492ecf4cb1..5010a0836e 100644 --- a/lib/efi_loader/efi_setup.c +++ b/lib/efi_loader/efi_setup.c @@ -350,7 +350,8 @@ efi_status_t efi_init_obj_list(void) goto out;

/* Execute capsules after reboot */ - if (IS_ENABLED(CONFIG_EFI_CAPSULE_ON_DISK) && + if (!IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE) && + IS_ENABLED(CONFIG_EFI_CAPSULE_ON_DISK) && !IS_ENABLED(CONFIG_EFI_CAPSULE_ON_DISK_EARLY)) ret = efi_launch_capsules(); out: diff --git a/lib/fwu_updates/Kconfig b/lib/fwu_updates/Kconfig new file mode 100644 index 0000000000..6de28e0c9c --- /dev/null +++ b/lib/fwu_updates/Kconfig @@ -0,0 +1,31 @@ +config FWU_MULTI_BANK_UPDATE + bool "Enable FWU Multi Bank Update Feature" + depends on EFI_HAVE_CAPSULE_SUPPORT + select PARTITION_TYPE_GUID + select EFI_SETUP_EARLY + help + Feature for updating firmware images on platforms having + multiple banks(copies) of the firmware images. One of the + bank is selected for updating all the firmware components + +config FWU_NUM_BANKS + int "Number of Banks defined by the platform" + depends on FWU_MULTI_BANK_UPDATE + help + Define the number of banks of firmware images on a platform + +config FWU_NUM_IMAGES_PER_BANK + int "Number of firmware images per bank" + depends on FWU_MULTI_BANK_UPDATE + help + Define the number of firmware images per bank. This value + should be the same for all the banks. + +config FWU_TRIAL_STATE_CNT + int "Number of times system boots in Trial State" + depends on FWU_MULTI_BANK_UPDATE + default 3 + help + With FWU Multi Bank Update feature enabled, number of times + the platform is allowed to boot in Trial State after an + update. diff --git a/lib/fwu_updates/Makefile b/lib/fwu_updates/Makefile index 5a59e4a833..1993088e5b 100644 --- a/lib/fwu_updates/Makefile +++ b/lib/fwu_updates/Makefile @@ -1,6 +1,7 @@ -# SPDX-License-Identifier: GPL-2.0+ +# SPDX-License-Identifier: GPL-2.0-or-later # # Copyright (c) 2022, Linaro Limited #

+obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu.o obj-$(CONFIG_FWU_MDATA_GPT_BLK) += fwu_gpt.o diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c index 10a0522333..390afe5f6f 100644 --- a/lib/fwu_updates/fwu.c +++ b/lib/fwu_updates/fwu.c @@ -113,6 +113,32 @@ u8 fwu_update_checks_pass(void) return !trial_state && boottime_check; }

+int fwu_trial_state_ctr_start(void) +{ + int ret; + u32 var_attributes; + efi_status_t status; + efi_uintn_t var_size; + u16 trial_state_ctr; + + var_size = (efi_uintn_t)sizeof(trial_state_ctr); + var_attributes = EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS; + + trial_state_ctr = ret = 0; + status = efi_set_variable_int(u"TrialStateCtr", + &efi_global_variable_guid, + var_attributes, + var_size, + &trial_state_ctr, false); + if (status != EFI_SUCCESS) { + log_err("Unable to increment TrialStateCtr variable\n"); + ret = -1; + } + + return ret; +} + int fwu_boottime_checks(void) { int ret;

The Dependable Boot specification[1] describes the structure of the firmware accept and revert capsules. These are empty capsules which are used for signalling the acceptance or rejection of the updated firmware by the OS. Add support for generating these empty capsules.

[1] - https://git.codelinaro.org/linaro/dependable-boot/mbfw/uploads/6f7ddfe3be24e...

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- Changes since V5: * Use capsule_type instead of capsule variable that was created earlier to check for the type of capsule * Remove use of payload variable in create_empty_capsule() as suggested by Etienne * Initialise the struct efi_capsule_header as suggested by Etienne

doc/mkeficapsule.1 | 29 ++++++++++---- tools/eficapsule.h | 8 ++++ tools/mkeficapsule.c | 92 ++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 115 insertions(+), 14 deletions(-)

diff --git a/doc/mkeficapsule.1 b/doc/mkeficapsule.1 index 09bdc24295..77ca061efd 100644 --- a/doc/mkeficapsule.1 +++ b/doc/mkeficapsule.1 @@ -8,7 +8,7 @@ mkeficapsule - Generate EFI capsule file for U-Boot

.SH SYNOPSIS .B mkeficapsule -.RI [ options "] " image-blob " " capsule-file +.RI [ options ] " " [ image-blob ] " " capsule-file

.SH "DESCRIPTION" .B mkeficapsule @@ -23,8 +23,13 @@ Optionally, a capsule file can be signed with a given private key. In this case, the update will be authenticated by verifying the signature before applying.

+Additionally, an empty capsule file can be generated for acceptance or +rejection of firmware images by a governing component like an Operating +System. The empty capsules do not require an image-blob input file. + + .B mkeficapsule -takes any type of image files, including: +takes any type of image files when generating non empty capsules, including: .TP .I raw image format is a single binary blob of any type of firmware. @@ -36,18 +41,16 @@ multiple binary blobs in a single capsule file. This type of image file can be generated by .BR mkimage .

-.PP -If you want to use other types than above two, you should explicitly -specify a guid for the FMP driver. - .SH "OPTIONS" + .TP .BI "-g\fR,\fB --guid " guid-string Specify guid for image blob type. The format is: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

The first three elements are in little endian, while the rest -is in big endian. +is in big endian. The option must be specified for all non empty and +image acceptance capsules

.TP .BI "-i\fR,\fB --index " index @@ -57,6 +60,18 @@ Specify an image index .BI "-I\fR,\fB --instance " instance Specify a hardware instance

+.PP +For generation of firmware accept empty capsule +.BR --guid +is mandatory +.TP +.BI "-A\fR,\fB --fw-accept " +Generate a firmware acceptance empty capsule + +.TP +.BI "-R\fR,\fB --fw-revert " +Generate a firmware revert empty capsule + .TP .BR -h ", " --help Print a help message diff --git a/tools/eficapsule.h b/tools/eficapsule.h index d63b831443..072a4b5598 100644 --- a/tools/eficapsule.h +++ b/tools/eficapsule.h @@ -41,6 +41,14 @@ typedef struct { EFI_GUID(0x4aafd29d, 0x68df, 0x49ee, 0x8a, 0xa9, \ 0x34, 0x7d, 0x37, 0x56, 0x65, 0xa7)

+#define FW_ACCEPT_OS_GUID \ + EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \ + 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8) + +#define FW_REVERT_OS_GUID \ + EFI_GUID(0xacd58b4b, 0xc0e8, 0x475f, 0x99, 0xb5, \ + 0x6b, 0x3f, 0x7e, 0x07, 0xaa, 0xf0) + /* flags */ #define CAPSULE_FLAGS_PERSIST_ACROSS_RESET 0x00010000

diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c index 5f74d23b9e..244c80e1f7 100644 --- a/tools/mkeficapsule.c +++ b/tools/mkeficapsule.c @@ -29,7 +29,13 @@ static const char *tool_name = "mkeficapsule"; efi_guid_t efi_guid_fm_capsule = EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID; efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;

-static const char *opts_short = "g:i:I:v:p:c:m:dh"; +static const char *opts_short = "g:i:I:v:p:c:m:dhAR"; + +enum { + CAPSULE_NORMAL_BLOB = 0, + CAPSULE_ACCEPT, + CAPSULE_REVERT, +} capsule_type;

static struct option options[] = { {"guid", required_argument, NULL, 'g'}, @@ -39,6 +45,8 @@ static struct option options[] = { {"certificate", required_argument, NULL, 'c'}, {"monotonic-count", required_argument, NULL, 'm'}, {"dump-sig", no_argument, NULL, 'd'}, + {"fw-accept", no_argument, NULL, 'A'}, + {"fw-revert", no_argument, NULL, 'R'}, {"help", no_argument, NULL, 'h'}, {NULL, 0, NULL, 0}, }; @@ -55,6 +63,8 @@ static void print_usage(void) "\t-c, --certificate <cert file> signer's certificate file\n" "\t-m, --monotonic-count <count> monotonic count\n" "\t-d, --dump_sig dump signature (*.p7)\n" + "\t-A, --fw-accept firmware accept capsule, requires GUID, no image blob\n" + "\t-R, --fw-revert firmware revert capsule, takes no GUID, no image blob\n" "\t-h, --help print a help message\n", tool_name); } @@ -564,6 +574,49 @@ void convert_uuid_to_guid(unsigned char *buf) buf[7] = c; }

+static int create_empty_capsule(char *path, efi_guid_t *guid, bool fw_accept) +{ + struct efi_capsule_header header = { 0 }; + FILE *f = NULL; + int ret = -1; + efi_guid_t fw_accept_guid = FW_ACCEPT_OS_GUID; + efi_guid_t fw_revert_guid = FW_REVERT_OS_GUID; + efi_guid_t capsule_guid; + + f = fopen(path, "w"); + if (!f) { + fprintf(stderr, "cannot open %s\n", path); + goto err; + } + + capsule_guid = fw_accept ? fw_accept_guid : fw_revert_guid; + + memcpy(&header.capsule_guid, &capsule_guid, sizeof(efi_guid_t)); + header.header_size = sizeof(header); + header.flags = 0; + + header.capsule_image_size = fw_accept ? + sizeof(header) + sizeof(efi_guid_t) : sizeof(header); + + if (write_capsule_file(f, &header, sizeof(header), + "Capsule header")) + goto err; + + if (fw_accept) { + if (write_capsule_file(f, guid, sizeof(*guid), + "FW Accept Capsule Payload")) + goto err; + } + + ret = 0; + +err: + if (f) + fclose(f); + + return ret; +} + /** * main - main entry function of mkeficapsule * @argc: Number of arguments @@ -592,6 +645,7 @@ int main(int argc, char **argv) privkey_file = NULL; cert_file = NULL; dump_sig = 0; + capsule_type = CAPSULE_NORMAL_BLOB; for (;;) { c = getopt_long(argc, argv, opts_short, options, &idx); if (c == -1) @@ -639,22 +693,46 @@ int main(int argc, char **argv) case 'd': dump_sig = 1; break; - case 'h': + case 'A': + capsule_type |= CAPSULE_ACCEPT; + break; + case 'R': + capsule_type |= CAPSULE_REVERT; + break; + default: print_usage(); exit(EXIT_SUCCESS); } }

+ if (capsule_type == (CAPSULE_ACCEPT | CAPSULE_REVERT)) { + fprintf(stderr, + "Select either of Accept or Revert capsule generation\n"); + exit(EXIT_FAILURE); + } + /* check necessary parameters */ - if ((argc != optind + 2) || !guid || - ((privkey_file && !cert_file) || - (!privkey_file && cert_file))) { + if ((capsule_type == CAPSULE_NORMAL_BLOB && + ((argc != optind + 2) || !guid || + ((privkey_file && !cert_file) || + (!privkey_file && cert_file)))) || + (capsule_type != CAPSULE_NORMAL_BLOB && + ((argc != optind + 1) || + ((capsule_type == CAPSULE_ACCEPT) && !guid) || + ((capsule_type == CAPSULE_REVERT) && guid)))) { print_usage(); exit(EXIT_FAILURE); }

- if (create_fwbin(argv[argc - 1], argv[argc - 2], guid, index, instance, - mcount, privkey_file, cert_file) < 0) { + if (capsule_type != CAPSULE_NORMAL_BLOB) { + if (create_empty_capsule(argv[argc - 1], guid, + capsule_type == CAPSULE_ACCEPT) < 0) { + fprintf(stderr, "Creating empty capsule failed\n"); + exit(EXIT_FAILURE); + } + } else if (create_fwbin(argv[argc - 1], argv[argc - 2], guid, + index, instance, mcount, privkey_file, + cert_file) < 0) { fprintf(stderr, "Creating firmware capsule failed\n"); exit(EXIT_FAILURE); }

Add documentattion for the FWU Multi Bank Update feature. The document describes the steps needed for setting up the platform for the feature, as well as steps for enabling the feature on the platform.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- Changes since V5: * Add some description about the reasoning for accept capsule needing image GUID as suggested by Takahiro

doc/develop/uefi/fwu_updates.rst | 156 +++++++++++++++++++++++++++++++ doc/develop/uefi/index.rst | 1 + doc/develop/uefi/uefi.rst | 2 + 3 files changed, 159 insertions(+) create mode 100644 doc/develop/uefi/fwu_updates.rst

diff --git a/doc/develop/uefi/fwu_updates.rst b/doc/develop/uefi/fwu_updates.rst new file mode 100644 index 0000000000..57d1b5b703 --- /dev/null +++ b/doc/develop/uefi/fwu_updates.rst @@ -0,0 +1,156 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (c) 2022 Linaro Limited + +FWU Multi Bank Updates in U-Boot +================================ + +The FWU Multi Bank Update feature implements the firmware update +mechanism described in the PSA Firmware Update for A-profile Arm +Architecture specification[1]. Certain aspects of the Dependable +Boot specification[2] are also implemented. The feature provides a +mechanism to have multiple banks of updatable firmware images and for +updating the firmware images on the non-booted bank. On a successful +update, the platform boots from the updated bank on subsequent +boot. The UEFI capsule-on-disk update feature is used for performing +the actual updates of the updatable firmware images. + +The bookkeeping of the updatable images is done through a structure +called metadata. Currently, the FWU metadata supports identification +of images based on image GUIDs stored on a GPT partitioned storage +media. There are plans to extend the metadata structure for non GPT +partitioned devices as well. + +Accessing the FWU metadata is done through generic API's which are +defined in a driver which complies with the u-boot's driver model. A +new uclass UCLASS_FWU_MDATA has been added for accessing the FWU +metadata. Individual drivers can be added based on the type of storage +media, and it's partitioning method. Details of the storage device +containing the FWU metadata partitions are specified through a U-Boot +specific device tree property `fwu-mdata-store`. Please refer to +U-Boot `doc <doc/device-tree-bindings/firmware/fwu-mdata.txt>`__ for +the device tree bindings. + +Enabling the FWU Multi Bank Update feature +------------------------------------------ + +The feature can be enabled by specifying the following configs:: + + CONFIG_EFI_CAPSULE_ON_DISK=y + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y + CONFIG_EFI_CAPSULE_FIRMWARE=y + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y + + CONFIG_FWU_MULTI_BANK_UPDATE=y + CONFIG_CMD_FWU_METADATA=y + CONFIG_DM_FWU_MDATA=y + CONFIG_FWU_MDATA_GPT_BLK=y + CONFIG_FWU_NUM_BANKS=<val> + CONFIG_FWU_NUM_IMAGES_PER_BANK=<val> + +in the .config file + +The first group of configs enable the UEFI capsule-on-disk update +functionality. The second group of configs enable the FWU Multi Bank +Update functionality. Please refer to the section +:ref:`uefi_capsule_update_ref` for more details on generation of the +UEFI capsule. + +Setting up the device for GPT partitioned storage +------------------------------------------------- + +Before enabling the functionality in U-Boot, certain changes are +required to be done on the storage device. Assuming a GPT partitioned +storage device, the storage media needs to be partitioned with the +correct number of partitions, given the number of banks and number of +images per bank that the platform is going to support. Each updatable +firmware image will be stored on an separate partition. In addition, +the two copies of the FWU metadata will be stored on two separate +partitions. + +As an example, a platform supporting two banks with each bank +containing three images would need to have 2 * 3 = 6 parititions plus +the two metadata partitions, or 8 partitions. In addition the storage +media can have additional partitions of non-updatable images, like the +EFI System Partition(ESP), a partition for the root file system etc. + +When generating the partitions, a few aspects need to be taken care +of. Each GPT partition entry in the GPT header has two GUIDs:: + + *PartitionTypeGUID* + *UniquePartitionGUID* + +The PartitionTypeGUID value should correspond to the *image_type_uuid* +field of the FWU metadata. This field is used to identify a given type +of updatable firmware image, e.g. u-boot, op-tee, FIP etc. This GUID +should also be used for specifying the `--guid` parameter when +generating the capsule. + +The UniquePartitionGUID value should correspond to the *image_uuid* +field in the FWU metadata. This GUID is used to identify images of a +given image type in different banks. + +Similarly, the FWU specifications defines the GUID value to be used +for the metadata partitions. This would be the PartitionTypeGUID for +the metadata partitions. + +When generating the metadata, the *image_type_uuid* and the +*image_uuid* values should match the *PartitionTypeGUID* and the +*UniquePartitionGUID* values respectively. + +Performing the Update +--------------------- + +Once the storage media has been partitioned and populated with the +metadata partitions, the UEFI capsule-on-disk update functionality can +be used for performing the update. Refer to the section +:ref:`uefi_capsule_update_ref` for details on how the update can be +invoked. + +On a successful update, the FWU metadata gets updated to reflect the +bank from which the platform would be booting on subsequent boot. + +Based on the value of bit15 of the Flags member of the capsule header, +the updated images would either be accepted by the u-boot's UEFI +implementation, or by the Operating System. If the Operating System is +accepting the firmware images, it does so by generating an empty +*accept* capsule. The Operating System can also reject the updated +firmware by generating a *revert* capsule. The empty capsule can be +applied by using the exact same procedure used for performing the +capsule-on-disk update. + +The task of accepting the different firmware images, post an update +may be done by multiple, separate components in the Operating +System. To help identify the firmware image that is being accepted, +the accept capsule passes the image GUID of the firmware image being +accepted. The relevant code in u-boot then sets the Accept bit of the +corresponding firmware image for which the accept capsule was +found. Only when all the firmware components in a bank have been +accepted does the platform transition to the regular state from trial +state. + +The revert capsule on the other hand does not pass any image GUID, +since reverting any image of the bank has the same result of the +platform booting from the other bank on subsequent boot. + +Generating an empty capsule +--------------------------- + +The empty capsule can be generated using the mkeficapsule utility. To +build the tool, enable:: + + CONFIG_TOOLS_MKEFICAPSULE=y + +Run the following commands to generate the accept/revert capsules:: + +.. code-block:: bash + + $ ./tools/mkeficapsule \ + [--fw-accept --guid <image guid>] | \ + [--fw-revert] \ + <capsule_file_name> + +Links +----- + +* [1] https://developer.arm.com/documentation/den0118/a/ - FWU Specification +* [2] https://git.codelinaro.org/linaro/dependable-boot/mbfw/uploads/6f7ddfe3be24e... - Dependable Boot Specification diff --git a/doc/develop/uefi/index.rst b/doc/develop/uefi/index.rst index 7e65dbc5d5..e26b1fbe05 100644 --- a/doc/develop/uefi/index.rst +++ b/doc/develop/uefi/index.rst @@ -13,3 +13,4 @@ can be run an UEFI payload. uefi.rst u-boot_on_efi.rst iscsi.rst + fwu_updates.rst diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst index 941e427093..536b278dd9 100644 --- a/doc/develop/uefi/uefi.rst +++ b/doc/develop/uefi/uefi.rst @@ -277,6 +277,8 @@ Enable ``CONFIG_OPTEE``, ``CONFIG_CMD_OPTEE_RPMB`` and ``CONFIG_EFI_MM_COMM_TEE`

[1] https://optee.readthedocs.io/en/latest/building/efi_vars/stmm.html

+.. _uefi_capsule_update_ref: + Enabling UEFI Capsule Update feature ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~