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

21 Dec 2021

On Tue, 21 Dec 2021 at 11:46, AKASHI Takahiro takahiro.akashi@linaro.org
wrote:
...
On Tue, Dec 21, 2021 at 11:17:47AM +0530, Sughosh Ganu wrote:
...
On Tue, 21 Dec 2021 at 10:33, AKASHI Takahiro <
takahiro.akashi@linaro.org>
...
wrote:
...
On Tue, Dec 21, 2021 at 10:05:57AM +0530, Sughosh Ganu wrote:
...
hi Masami,
On Tue, 21 Dec 2021 at 05:40, Masami Hiramatsu <
masami.hiramatsu@linaro.org>
...
wrote:
...
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.
Okay. WIll do it.
...
...



+/**


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.
I have moved the function declarations to fwu.h. The one function
prototype
...
that I have in fwu_mdata.h is the one which has the metadata
structure as
...
...
...
one of it's parameters. Same for the ops as well. The get_mdata
function
...
...
...
has the metadata structure as its parameter. Are you facing any
issues
...
...
with
...
the current structure of the files.
struct fwu_mdata;
int fwu_get_mdata(struct fwu_**mdata);
would be good enough?
Yes, I had considered putting this kind of declaration in fwu.h. But I
decided against it thinking that any function declaration that involved
the
...
fwu metadata structure can be put in one file. But I just want to
understand if there is some issue in putting these declarations in the
fwu_mdata.h. The rest of the function declarations and symbols are put in
the fwu.h header. If you see, I only include the fwu.h in the
efi_firmware.c and efi_capsule.c.
...
I'm not sure whether it is a good idea that we re-use the *same* file
in other software, but I would suggest you to use standard POSIX types
like 'uint32_t' instead of 'u32' anyway.
Hmm, this is on the same lines to the types used in the capsule code.
That
...
was the primary reason that I stuck with u<size> types. Any issue with
using the short type? The Linux kernel seems to be using it.
That is my point. Why should we use linux-specific types in
other software, especially when we want to import a generic
header, which is essentially platform agnostic?
Well, I was not aware that the header was to be imported in other software,
till Masami explained. I will change the types in the fwu_mdata.h header.
-sughosh
...
-Takahiro Akashi
...
-sughosh
...
-Takahiro Akashi
...
-sughosh
...
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

    