Re: [RFC PATCH v2 1/8] FWU: Add FWU metadata structure and functions for accessing metadata

[Masami Hiramatsu <masami.hiramatsu@linaro.org>]

Hi Sughosh,

2021年12月19日(日) 16:06 Sughosh Ganu <sughosh.ganu@linaro.org>:
>
> 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 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 V1:
> * Move all function declarations to a separate header fwu.h
> * Rename metadata with mdata for all symbols
> * Drop the parameter in the function fwu_revert_boot_index
>   as suggested by Etienne
>
>  include/fwu.h               |  28 +++++
>  include/fwu_mdata.h         | 102 ++++++++++++++++
>  lib/fwu_updates/fwu_mdata.c | 236 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 366 insertions(+)
>  create mode 100644 include/fwu.h
>  create mode 100644 include/fwu_mdata.h
>  create mode 100644 lib/fwu_updates/fwu_mdata.c
>
> diff --git a/include/fwu.h b/include/fwu.h
> new file mode 100644
> index 0000000000..e6bc3e6b73
> --- /dev/null
> +++ b/include/fwu.h
> @@ -0,0 +1,28 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (c) 2021, Linaro Limited
> + */
> +
> +#if !defined _FWU_H_
> +#define _FWU_H_
> +
> +#include <efi.h>
> +
> +#include <linux/types.h>
> +
> +#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_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);
> +int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank);
> +
> +#endif /* _FWU_H_ */
> diff --git a/include/fwu_mdata.h b/include/fwu_mdata.h
> new file mode 100644
> index 0000000000..11eb570012
> --- /dev/null
> +++ b/include/fwu_mdata.h
> @@ -0,0 +1,102 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (c) 2021, Linaro Limited
> + */
> +
> +#if !defined _FWU_MDATA_H_
> +#define _FWU_MDATA_H_
> +
> +#include <efi.h>
> +#include <uuid.h>
> +
> +#include <linux/types.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;
> +       u32 accepted;
> +       u32 reserved;
> +};

Could you explicitly pack these metadata data structures?
Since these metadata will be shared among bootloaders (TF-A, SCP-firmware),
it is better to ensure that those are packed and fixed offset for each field.

> +
> +/**
> + * 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];
> +};
> +
> +/**
> + * 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 {
> +       u32 crc32;
> +       u32 version;
> +       u32 active_index;
> +       u32 previous_active_index;
> +
> +       struct fwu_image_entry img_entry[CONFIG_FWU_NUM_IMAGES_PER_BANK];
> +};
> +
> +/**
> + * @get_active_index: get the current active_index value
> + * @update_active_index: update the active_index value
> + * @get_image_alt_num: get the alt number to be used for the image
> + * @mdata_check: check the validity of the FWU metadata partitions
> + * @revert_boot_index: set the active_index to previous_active_index
> + * @set_accept_image: set the accepted bit for the image
> + * @clear_accept_image: clear the accepted bit for the image
> + * @get_mdata() - Get a FWU metadata copy
> + */
> +struct fwu_mdata_ops {
> +       int (*get_active_index)(u32 *active_idx);
> +
> +       int (*update_active_index)(u32 active_idx);
> +
> +       int (*get_image_alt_num)(efi_guid_t image_type_id, u32 update_bank,
> +                                int *alt_num);
> +
> +       int (*mdata_check)(void);
> +
> +       int (*revert_boot_index)(void);
> +
> +       int (*set_accept_image)(efi_guid_t *img_type_id);
> +
> +       int (*clear_accept_image)(efi_guid_t *img_type_id, u32 bank);
> +
> +       int (*get_mdata)(struct fwu_mdata **mdata);
> +};
> +
> +int fwu_get_mdata(struct fwu_mdata **mdata);
> +struct fwu_mdata_ops *get_plat_fwu_mdata_ops(void);

Also, could you also move these function prototypes and operators to
fwu? I would like to copy this header file to the boot loaders as is.
In that case, I just need the definition of the metadata data structure,
but no function prototypes.

Thank you,

> +
> +#endif /* _FWU_MDATA_H_ */
> diff --git a/lib/fwu_updates/fwu_mdata.c b/lib/fwu_updates/fwu_mdata.c
> new file mode 100644
> index 0000000000..348e9c85f7
> --- /dev/null
> +++ b/lib/fwu_updates/fwu_mdata.c
> @@ -0,0 +1,236 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2021, Linaro Limited
> + */
> +
> +#include <fwu_mdata.h>
> +
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +
> +static struct fwu_mdata_ops *get_fwu_mdata_ops(void)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops =  get_plat_fwu_mdata_ops();
> +       if (!ops) {
> +               log_err("Unable to get fwu ops\n");
> +               return NULL;
> +       }
> +
> +       return ops;
> +}
> +
> +/**
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->get_active_index) {
> +               log_err("get_active_index() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->get_active_index(active_idx);
> +}
> +
> +/**
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->update_active_index) {
> +               log_err("update_active_index() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->update_active_index(active_idx);
> +}
> +
> +/**
> + * fwu_get_image_alt_num() - Get the dfu alt number to be used for capsule update
> + * @image_type_id: 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->get_image_alt_num) {
> +               log_err("get_image_alt_num() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->get_image_alt_num(image_type_id, update_bank, alt_num);
> +}
> +
> +/**
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->mdata_check) {
> +               log_err("mdata_check() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->mdata_check();
> +}
> +
> +/**
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->revert_boot_index) {
> +               log_err("revert_boot_index() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->revert_boot_index();
> +}
> +
> +/**
> + * 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
> + *
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->set_accept_image) {
> +               log_err("set_accept_image() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->set_accept_image(img_type_id);
> +}
> +
> +/**
> + * 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
> + *
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->clear_accept_image) {
> +               log_err("clear_accept_image() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->clear_accept_image(img_type_id, bank);
> +}
> +
> +/**
> + * 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)
> +{
> +       struct fwu_mdata_ops *ops;
> +
> +       ops = get_fwu_mdata_ops();
> +       if (!ops)
> +               return -EPROTONOSUPPORT;
> +
> +       if (!ops->get_mdata) {
> +               log_err("get_mdata() method not defined for the platform\n");
> +               return -ENOSYS;
> +       }
> +
> +       return ops->get_mdata(mdata);
> +}
> --
> 2.17.1
>


-- 
Masami Hiramatsu