Commit Graph

11 Commits

Author SHA1 Message Date
Heinrich Schuchardt
c0c21d67f0 efi_loader: make variable store size customizable
Currently the size of the buffer to keep UEFI variables in memory is fixed
at 16384 bytes. This size has proven to be too small for some use cases.

Make the size of the memory buffer for UEFI variables customizable.

Reported-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2020-12-31 14:27:41 +01:00
Heinrich Schuchardt
dd12c6a446 efi_loader: remove empty comment line
Remove a line leading to a warning in make htmldocs.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-08-24 16:37:53 +02:00
Ilias Apalodimas
e01aed47d6 efi_loader: Enable run-time variable support for tee based variables
We recently added functions for storing/restoring variables
from a file to a memory backed buffer marked as __efi_runtime_data
commit f1f990a8c9 ("efi_loader: memory buffer for variables")
commit 5f7dcf079d ("efi_loader: UEFI variable persistence")

Using the same idea we now can support GetVariable() and GetNextVariable()
on the OP-TEE based variables as well.

So let's re-arrange the code a bit and move the commmon code for
accessing variables out of efi_variable.c. Create common functions for
reading variables from memory that both implementations can use on
run-time. Then just use those functions in the run-time variants of the
OP-TEE based EFI variable implementation and initialize the memory
buffer on ExitBootServices()

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-08-01 11:57:41 +02:00
Heinrich Schuchardt
627ab390d8 efi_loader: describe EFI_VAR_FILE_MAGIC
Add documentation for EFI_VAR_FILE_MAGIC used in the file format for UEFI
variables.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-16 12:37:03 +02:00
Heinrich Schuchardt
7dda16343d efi_loader: pre-seed UEFI variables
Include a file with the initial values for non-volatile UEFI variables
into the U-Boot binary. If this variable is set, changes to variable PK
will not be allowed.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-16 12:37:02 +02:00
Heinrich Schuchardt
99bfab8b58 efi_loader: identify PK, KEK, db, dbx correctly
To determine if a varible is on the of the authentication variables
PK, KEK, db, dbx we have to check both the name and the GUID.

Provide a function converting the variable-name/guid pair to an enum and
use it consistently.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-16 12:37:02 +02:00
Heinrich Schuchardt
012c56ac76 efi_loader: restructure code for TEE variables
When using secure boot functions needed both for file and TEE based UEFI
variables have to be moved to the common code module efi_var_common.c.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-16 12:37:02 +02:00
Heinrich Schuchardt
f1f990a8c9 efi_loader: memory buffer for variables
Saving UEFI variable as encoded U-Boot environment variables does not allow
support at runtime.

Provide functions to manage a memory buffer with UEFI variables.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:17 +02:00
Heinrich Schuchardt
5f7dcf079d efi_loader: UEFI variable persistence
Persist non-volatile UEFI variables in a file on the EFI system partition.

The file is written whenever a non-volatile UEFI variable is changed after
initialization of the UEFI sub-system.

The file is read during the UEFI sub-system initialization to restore
non-volatile UEFI variables.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:17 +02:00
Heinrich Schuchardt
01df8cf336 efi_loader: separate UEFI variable API from implemementation
Separate the remaining UEFI variable API functions GetNextVariableName and
QueryVariableInfo() from internal functions implementing them.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:16 +02:00
Heinrich Schuchardt
f2d2b3a11c efi_loader: prepare for read only OP-TEE variables
We currently have two implementations of UEFI variables:

* variables provided via an OP-TEE module
* variables stored in the U-Boot environment

Read only variables are up to now only implemented in the U-Boot
environment implementation.

Provide a common interface for both implementations that allows handling
read-only variables.

As variable access is limited to very few source files put variable
related definitions into new include efi_variable.h instead of efi_loader.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:16 +02:00